Nuclear Weapon News and Background
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Russia rejects arms deal
Talks: Missile-defense pact fails; leaders sign agreements to reduce nuclear-attack risk.
Mercury News Washington Bureau
Mercury News Moscow Bureau
Posted at 11:20 a.m. PDT Monday, June 5, 2000

MOSCOW -- Facing a determined new adversary at an important moment in relations between Moscow and Washington, President Clinton failed Sunday to convince Russian President Vladimir Putin that a U.S. missile-defense system is necessary and wouldn't threaten the military balance between the world's dominant nuclear powers.

"We're against having a cure which is worse than the disease," said a stone-faced Putin during a joint news conference with Clinton.

Appearing together in the czarist splendor of St. George's Hall in the Kremlin, Putin vowed good relations between the United States and Russia. The frank, businesslike atmosphere of the talks, in contrast to the frigidity of the Cold War and the unpredictability of Putin's predecessor, Boris Yeltsin, may mark the opening of a new chapter in the long rivalry between America and Russia.

Putin displayed neither Soviet-style hostility nor the personal warmth that characterized Yeltsin's relationship with Clinton. His steely resolve in the arms talks, coupled with a dip into American politics, suggested that Putin considers Russia and the United States equals that will clash on some issues, cooperate on others and agree to disagree on the rest.

Sitting rather than standing next to the much-taller American president, refusing to smile in the face of criticism, Putin used his premier appearance on the world stage to signal that he wants Russia and its leader to be treated with greater respect and deference.

Even keel

``He was personal but not too personal,'' said Dmitri Trenin, an analyst with the Moscow Carnegie Center, a Moscow independent think tank. ``He never went so far as to suggest there's a friendship emerging. He wants to keep it on an even keel with Clinton's successor.''

Putin managed to win Clinton's endorsement, said Pavel Felgengauer, an often critical Russian defense analyst, and ``didn't give anything away in return.''

Putin and Clinton signed two agreements to reduce the threat of nuclear attack -- one to dispose of 68 tons of weapons-grade plutonium so it cannot fall into the hands of ``rogue'' nations or terrorists, and one to share early warnings of missile launches to avoid a mistaken counterattack.

But Putin flatly rejected Clinton's proposal that the two nations amend the 28-year-old Anti-Ballistic Missile Treaty. Negotiated at the height of the Cold War, the treaty prevents either side from building a national missile defense so that both remain vulnerable to attack and thus are deterred from ever starting a war.

Putin agreed that there is a new threat of a limited missile attack from rogue nations such as North Korea, but said there should be a better way to stop it than upsetting the strategic balance between the United States and Russia. ``There are a lot of problems there,'' he said.

He and Clinton agreed to dispatch aides to start negotiating a potentially sweeping arms-control agreement this summer, linking the changes the United States wants in the ABM Treaty with deeper nuclear-arms cuts that Russia needs to reduce the cost of maintaining its nuclear arsenal.

In agreeing to link the negotiations on offensive and defensive weapons, Clinton signaled that he may be willing to cut the U.S. nuclear arsenal more deeply than the Pentagon wants in order to win Russian approval to amend the ABM Treaty.

Russia's proposal

Already committed to reducing each nation's nuclear arsenal to between 3,000 and 3,500 warheads, Russia has proposed cutting to 1,500 warheads under a new Strategic Arms Reduction Treaty, known as START III.

The Joint Chiefs of Staff told Congress a few weeks ago that the United States nuclear doctrine requires a minimum of 2,000 to 2,500 warheads.

``If we were to come down below that, it would require us to change our strategic plan,'' Clinton said. ``We believe it would be much better, if we were going to do that, if we could also know that we were defending ourselves against a new threat, which we believe is real.''

Such a grand compromise could also satisfy the objections of China, which fears a U.S. defense would make its small nuclear force impotent, and America's European allies, who fear it would trigger a new arms race between the Americans and Russians with them in the middle.

Clinton has three more meetings scheduled with Putin this year where they could finalize an agreement, but less than eight months left in his presidency.

Even if he did sign a last-minute agreement with Putin -- as former President George Bush signed the START II treaty with Russia after losing to Clinton in 1992 but before leaving office -- Clinton's deal would be dead on arrival in the Republican-controlled Senate.

Aware that he likely will deal with the next American president, Putin all but ignored Clinton's implied warning that Russia might get a better deal now than it would after November's election.

Vice President Al Gore, the expected Democratic nominee for president, echoes Clinton administration policy in saying that Russian agreement is critical to maintaining the ABM Treaty while also allowing the United States to field a limited missile-defense system. But Republican presidential candidate George W. Bush says that if the Russians didn't agree to amend the treaty, he would exercise an escape clause and build the missile defense anyway.

``We're familiar with the programs of the two main candidates,'' Putin said. ``No matter who gets to be president, we're willing to go forward on either one of these approaches.''

Clinton came to Moscow as Putin assumes power in the first democratic change of government in Russia's 1,100-year history.

He pressed the new leader to nurture his country's fragile young democracy, to be tough enough to push through economic reforms, but not so tough that he endangers individual liberty.

``I have come to Moscow at an important time,'' Clinton said, noting that Russia has a new president, new government, new legislature and a newly recovering economy.

``I'm encouraged by the economic plan President Putin has outlined and by the current recovery. I look forward to Russia's continuing to implement proposed reforms that will actually make the recovery last -- reforms such as tax reform, anti-money laundering legislation, strong property rights protections.''

Yet he said he also criticized Putin for Russia's brutal war against separatist rebels in the republic of Chechnya and for a recent crackdown on independent news media.

Putin seemed unmoved by the criticisms or by the disagreement over nuclear strategy and insistent that neither should hurt relations between the two countries.

``Problems like this exist, and have existed, and probably will exist. That is not important,'' he said.

Worse than we knew
By Pat Ortmeyer & Arjun Makhijani
Bulletin of the Atomic Scientists
Nov/Dec 97, Vol 53 No. 7

On August 1, the National Cancer Institute (NCI) revealed that as a result of U.S. nuclear tests conducted in the atmosphere in Nevada, American children were actually exposed to 15 to 70 times as much radiation as had been previously reported to Congress. As a result, many thousands of today's adults are at risk of developing thyroid cancer.

This information comes from fragments of a congressionally mandated study, 14 years in the making. The NCI report details estimated radiation doses to the thyroid gland due to releases of radioactive iodine 131. Most of the releases occurred from 1951 to 1958.

Although areas near the Nevada Test Site were most often contaminated, the newly released data show that virtually the entire continental United States was affected and "hot spots" occurred in unpredictable places far from the site. These hot spots occurred because rainstorms sometimes caused locally heavy deposits of fallout. As a result, some children in large portions of the Midwest, parts of New England, and areas east and northeast of the test site (Idaho, Montana, and the Dakotas) received doses of iodine 131 as high as 112 rads.

These dose estimates refer not to whole-body exposure, but to the concentration of iodine 131 in the thyroid gland, which occurred primarily through the "milk pathway." As cows and goats grazed in fallout-contaminated pastures, iodine 131 contaminated their milk. Children received high thyroid doses because they drank much more milk than adults, they had smaller thyroids, and their thyroids were growing. In making its county-by-county estimates, NCI used both milk production and consumption patterns as well as weather data.

What the government knew

Given the location of the U.S. test site, none of the NCI's findings should come as a surprise to the nuclear weapons establishment, which knew from the beginning that a western test site would spread contamination across most of the country. In 1948, for instance, the committee assigned to choosing a location was told by U.S. Air Force Meteorologist Col. B. G. Holzman that an East Coast site would be advisable "because the United States is predominantly under the influence of westerly winds."1

Instead, the committee chose a western site because the weapons labs were nearby, which it felt would be helpful in "accelerating the pace of the weapons development program."2

Estimates of thyroid doses, first reported in testimony to Congress in 1959-and still cited in 1997-ranged from 0.2 to 0.4 rad. (According to the NCI, 0.4 rad is roughly the radiation dose delivered by one mammogram.) But American children on average actually received an estimated cumulative dose to the thyroid of 6 to 14 rads, and in the 24 most heavily contaminated counties, doses were between 27 and 112 rads.

The exposure of millions of children is especially troubling because much of it could have been avoided. The Atomic Energy Commission (AEC) learned about the risks of fallout and the prevalence of hot spots with the first atomic test, and the AEC was aware of the danger of consuming contaminated milk during most of the years of testing in Nevada.

Early warning

Authorities had an early tangible warning that fallout from nuclear tests would travel far from the site of a detonation and that care would be needed to contain it. Fallout was discovered 200 miles from the test site where "Trinity," the first nuclear bomb, was detonated in New Mexico in July 1945. As a result, Stafford Warren, the Manhattan Project's chief of radiological safety, recommended to Gen. Leslie Groves, head of the project, that future tests should be conducted at least 150 miles away from civilian populations.3

The Trinity test also resulted in at least one hot spot in Indiana, over 1,000 miles away. A month after the test, customers of the Eastman Kodak Company began complaining about buying fogged X-ray film. After investigating, an Eastman Kodak physicist determined that packing material (made from corn husks at a plant in Indiana) had been radioactively contaminated. The physicist also deduced that the origin of the contamination was an atomic explosion. His knowledge of the secret project was not altogether surprising: the Kodak Company ran the Tennessee Eastman uranium processing plant at the Oak Ridge National Laboratory.

Kodak also reported problems from fallout after the first test in Nevada in January 1951, but this time they occurred as far away as company headquarters in Rochester, New York. After a snowstorm, Geiger counters at the Kodak plant showed readings 25 times above normal. When Kodak complained and threatened to sue, the Atomic Energy Commission agreed to give the company "advance information on future tests" including "expected distribution of radioactive material in order to anticipate local contamination."4

In fact, the entire photographic film industry was warned about fallout. Throughout the atmospheric testing program, AEC officials gave the photographic industry maps and forecasts of potential contamination, as well as expected fallout distributions, which enabled them to purchase uncontaminated materials and take other protective measures. The National Association of Photographic Manufacturers was also given some data on the nature of the test shots "for their own information."

But the AEC did not see fit to provide milk producers or consumers with similar information, even when the significance of the milk pathway became clear.

One of the better known hot spots occurred in Albany, New York, after the "Simon" test in April 1953. After a heavy rainstorm, students in a college radiochemistry class noticed that their Geiger counters showed readings as high as 1,000 times above normal.5

Measurements taken from roofs, puddles, buildings, and foliage around town showed equally elevated readings. In a 1954 report, the AEC described this incident as "an interesting example of a small area of very intense fallout."

But the AEC report that evaluated the Albany incident also indicated that fallout as far as 600 miles from the test site, in areas such as western Kansas, could deposit 1,000 to 100,000 times the radioactivity recorded in Albany. The report also recommended that, since hot spots were more likely to occur during months with the greatest precipitation, "Total fallout in the United States could be reduced somewhat by scheduling test series in the late fall," when storms were least likely to occur.6

This recommendation was largely ignored.

Deceit and denial

Although public concern about fallout grew in the early 1950s, the AEC consistently denied that the public was in danger. But the AEC's collection of milk samples was haphazard at best. For example, in 1953, the Public Health Service was asked to obtain milk samples in St. George, Utah, near the test site. But the service took a sample from a carton of milk purchased in a store, not from a local farm or dairy — at a time when the majority of residents of southwest Utah obtained milk from their own cows and many others purchased milk from neighboring farms.

According to Morgan S. Seal, a fallout monitor with the Public Health Service, the testing procedure was not very useful either. "In the case of milk, we even treated it with perchloric acid to get rid of all the organic residue. . . . We knew for a fact then that those oxidating techniques completely eliminated any iodine in the material that you were treating."7

Studies on animals exposed to iodine 131 had been going on since the 1940s, although they primarily involved direct measurement of the thyroid to detect iodine uptake rather than whether the radioactive iodine would contaminate the animal's milk.

In 1953, however, researchers at the Hanford Nuclear Reservation studied milk samples from sheep that had been fed iodine 131 pellets and concluded that similar iodine levels in bovine milk "suggest that [iodine 131] would be found in such dairy products as skim milk, cottage cheese, and whey."8

In 1954, the Journal of Dairy Research was more direct in discussing the risk to humans of iodine in milk, indicating that "cows grazing in the neighborhood [near a nuclear power plant accident] may ingest sufficient of the isotope to constitute a danger to the consumers of their milk."9 Also in 1954, AEC-funded research determined that the elevated levels of iodine found in animal thyroids in Tennessee were linked to fallout from nuclear tests.10

Additional evidence of the danger of the milk pathway was presented by delegates to the U.N. Conference on Peaceful Uses of Atomic Energy in 1955. One research paper argued that radioactive iodine deposited in grazing areas became so highly concentrated in milk that the then-permissible levels of iodine 131 in the air were ten thousand times too high. "This limit should be reduced by four orders of magnitude to assure radiation safety for grazing animals. Approximately the same reduction is required for the safety of humans eating large quantities of fresh garden produce and drinking milk from cows grazing on iodine 131-contaminated pasture."11 An Oxford University delegation to the conference stressed that "human beings whose diet consists largely of milk, notably infants . . . because of their youth may be considered super-susceptible to the effects of radiation."12

Although the Atomic Energy Commission ignored these recommendations, elsewhere attitudes were changing. In 1957, when a fire at Britain's Windscale reprocessing plant caused the release of between 16,200 and 27,000 curies of radioiodine, officials ordered all milk produced within a 200-square-mile area around the plant to be dumped as a precautionary measure. By comparison, cumulative releases of iodine 131 from atmospheric tests during the 1950s were around 150 million curies, but at no time did the government order that milk be dumped.

In 1959, in response to public concerns about fallout, President Dwight D. Eisenhower created the Federal Radiation Council and charged it with setting federal radiation standards. When it was discovered that iodine levels in milk in Utah exceeded its standards — and that fallout standards were being exceeded in hot spots around the country — state officials in Utah and Minnesota decided to divert contaminated milk from the market. But in 1962, the radiation council (whose members included the chairman of the AEC and the Secretary of Defense) made the remarkable determination that the radiation guidelines should not be applied to fallout without further detailed studies because "any possible health risk which may be associated with exposures even many times above the guide levels would not result in a detectable increase in the incidence of disease." The council also concluded that preventive measures, presumably such as diverting milk, may actually "have a net adverse rather than favorable effect on the public well-being."13 In testimony before Congress in 1969, council chairman Paul C. Tompkins defended the failure to divert milk from the market by claiming that doing so would have caused malnutrition.14

In 1962 the AEC's Fallout Studies Branch produced a report indicating that after the "Harry" test in 1953, children living in St. George, Utah may have received doses to the thyroid of radioiodine as high as 120 to 440 rads. The AEC tried to suppress the report, but it was eventually released. However, a committee review appended to the report warned that its "specific conclusions must be regarded with considerable reservation."

The evidence of high thyroid doses from contaminated milk continued to grow. In 1966, another AEC study showed that children both directly downwind and far away from the test site had received high thyroid doses of iodine 131 from drinking contaminated milk. The highest thyroid doses were to children directly downwind: infants in St. George, Utah were estimated to have received 120 rads. But across the country, researchers found significant doses to children from iodine fallout: 46 rads in Salt Lake City, Utah; 56 rads in Roswell, New Mexico; 51 rads in Grand Junction, Colorado; 19 rads in Amarillo, Texas; and 15 rads in Albany, New York.14

Fallout from fallout

The National Cancer Institute study, only small portions of which were released in August, did not directly assess the risk of cancer as it relates to fallout. But researchers did predict that some 10,000 to 75,000 excess thyroid cancers could be expected from the reported doses, and that only 30 percent of those cancers had been diagnosed to date. In 1977 the NCI reported that the incidence of thyroid cancer was on the rise: in a 1969­71 survey there were 3.9 cases of thyroid cancer per 100,000 people, up from 2.4 cases per 100,000 in 1947 — an increase of 62 percent. For Caucasians between the ages of 20 and 35 the rate doubled.

However, concluding that cases of thyroid cancer are a result of exposure to iodine 131 is not straightforward; during the years of atmospheric testing it was also common for physicians to treat an assortment of disorders with X-rays and other radiation sources. For example, from the 1940s to the 1960s, nasal applicators containing sealed radium 226 sources were used to treat nasal and inner ear problems and to reduce swelling of lymphoid tissue.

The National Cancer Institute estimates that around 160 million people — virtually everyone living in the United States at the time — received some iodine dose from fallout. But those most at risk, according to a peer-reviewed 1995 study, are people who were exposed while under 15 years of age and who received a radiation dose of 10 rads or more. The risk is greatest for those exposed before the age of five.15

More specific numbers have not been released, but simple demographics coupled with the published numbers indicate that millions of people who were then under 15 may have been exposed to 10 rads or more. (About five to 10 percent of thyroid cancers are fatal; survivors require lifelong treatment with a synthetic thyroid hormone essential for metabolism and other physiological functions.)

What should be done?

The National Cancer Institute, which has been working on its study for nearly 14 years, argues that more research is needed. But the need to address uncertainties should not be an excuse for further delay — the government has a responsibility to the 160 million people who were unknowingly exposed. The complete report and the follow-up studies conducted by the National Academy of Sciences' Institute of Medicine should be released promptly so that those at risk can be notified and given appropriate medical screening.

In its study of populations exposed to iodine 131 releases at Hanford, the Agency for Toxic Substances and Disease Registry recommended screening all those who had received doses of 10 rads or more. Average doses to children in the 24 most affected counties in the NCI study were far greater (27 to 112 rads).

The thyroid survey in the Marshall Islands also offers a precedent: although contamination levels varied widely and no dose reconstruction was carried out, every Marshallese born before 1965 was eventually offered a free clinical examination.

These precedents, at Hanford and in the Marshall Islands, offer a foundation upon which a public policy response to thyroid doses from iodine fallout could be based.

The NCI claims that it did not release dose data four years ago when the preliminary results were known because the report was not yet complete. However, public health officials should have been informed, given the high dose estimates for many counties across the country. If estimated doses were revised downward in the final version, then no harm would have been done. Since thyroid cancer is highly treatable, screening could have been instituted earlier, possibly saving lives.

The failure to provide adequate warning of the dangers of fallout should not be compounded by a failure to release full information to the millions affected by iodine 131 fallout from atmospheric nuclear testing.

Pat Ortmeyer is outreach coordinator for the Institute for Energy and Environmental Research (ieer), and managing editor of the Institute's Science for Democratic Action. Arjun Makhijani is president of ieer.

U.S. Plan to Renovate Warheads Stirs Opposition
By Walter Pincus
Washington Post Staff Writer
Sunday , March 26, 2000 ; A02

The Energy Department plans to renovate more than 6,000 aging nuclear warheads over the next 15 years, almost double the number that the United States is allowed to deploy under the START II arms reduction treaty, according to senior U.S. officials.

The added warheads will make up what Energy officials refer to as the "inactive reserve," some 2,500 to 3,000 refurbished warheads that would give the United States the ability to match another country's sudden production of additional warheads.

This plan, the legacy of a 6-year-old presidential decision, is coming under sharp criticism from arms control proponents. They contend that it is unnecessary and possibly counterproductive to maintain an arsenal of 6,000 warheads at a time when President Clinton and other U.S. officials are attempting to persuade India, Pakistan, North Korea, China and Russia to halt or restrain their nuclear weapons programs.

"While the president is talking about the dangers of nuclear weapons, technicians at the national laboratories are working to refurbish a stockpile the size of which is unaffected by any agreement or treaty," said Janne Nolan, director of international programs for the Century Foundation and a former official in the Arms Control and Disarmament Agency.

Robert S. Norris, a nuclear arms specialist with the Natural Resources Defense Council, has dubbed the plan "Cold War lite."

"This is the dark side of the stockpile. We will spend vast billions to refurbish warheads which we [cannot deploy but] haven't decided to throw away," Norris said.

On the other hand, a Defense Department official with responsibility for strategic weapons contended that until Russia ratifies START II, the United States must hedge its bets against a possible reversal of that agreement. After the treaty enters into force and "we gain confidence" that the Russians are abiding by it, the official said, "then we, too, can eliminate additional warheads."

The United States spends about $4.6 billion a year to maintain its nuclear arsenal. The Energy Department does not separately break out the cost of the 3,000 to 3,500 deployed warheads from the cost of the 2,500 to 3,000 that will be held in reserve. But to address what the acting head of Energy's defense programs called "shortfalls in production readiness," the department is requesting $55 million in the supplemental appropriations bill before Congress.

The funds are "essential," Brig. Gen. Thomas F. Gioconda told a House Armed Services subcommittee last week, to support "important workloads" at three plants involved in the refurbishing program: Pantex in Texas, Y-12 in Tennessee and the so-called Kansas City plant in Missouri.

The first Strategic Arms Reduction Treaty (START I), signed in 1991, permits Washington and Moscow to maintain 6,000 strategic warheads on bombers, submarines and land-based missiles. The 1993 START II agreement would reduce that limit to between 3,000 and 3,500 deployed warheads. Neither treaty restricts the number of warheads kept in reserve.

Although the Senate ratified START II in 1996, the Russian Duma has delayed voting on it, so the treaty has yet to go into effect. Both sides have cut their arsenals to the START I level, but Congress has prohibited the U.S. military from going below 6,000 deployed warheads until Moscow ratifies START II.

Russian leaders--including Vladimir Putin, the almost certain winner of a presidential election today--repeatedly have promised to push the treaty through the Duma. Russian and American officials also have had preliminary discussions about a START III agreement that could further reduce nuclear stockpiles.

The plan to keep an "inactive reserve" of 2,500 to 3,000 more warheads than permitted to be deployed under START II is the product of a little-publicized Clinton administration nuclear policy called "lead and hedge." It was described to Congress in 1996 by Harold P. Smith Jr., then assistant to the secretary of defense for nuclear, chemical and biological defense programs.

He said that while the administration "leads" by pushing for force reductions in arms control negotiations, the United States has to "retain the ability to hedge by returning to START I levels."

Smith said the policy was approved by President Clinton in September 1994 as part of a Nuclear Posture Review, an annual document setting guidelines for America's nuclear forces.

Michael Krepon, president of the Henry L. Stimson Center and an arms reduction advocate, said the Pentagon has pressed for the "inactive reserve" of warheads because its plan for how to fight a nuclear war is basically unchanged from a decade ago.

"The Pentagon has not revised targeting doctrine since the Cold War," Krepon said. "It has simply downsized the active requirement and put half of what they say they need on the shelf. But the war plan requirement for 6,000 detonations has never changed."

An informal Russian proposal to reduce the number of warheads on each side to 1,500 in the future START III talks has met opposition from some U.S. defense officials who contend that that number would not be enough to ensure deterrence.

The Russian military, strapped for funds, appears to be moving toward a 1,500-warhead arsenal in any event. But, Krepon said, the difference in the size of the Russian and U.S. stockpiles is so great that "the Russians are looking at a U.S. breakout level"--strategic jargon for the ability to field a vastly superior nuclear force.

Newly reconstructed B-61 bombs for strategic bombers already have gone into the U.S. stockpile, while the first refurbished W-87 warheads are now being delivered to the Air Force for rearming America's 50 Peacekeeper intercontinental ballistic missiles. The Peacekeeper carries 10 W-87s, each of which has 20 times the explosive power of the U.S. bomb that destroyed Hiroshima.

The program also will see refurbished W-87s put on the 500 deployed Minuteman III ICBMs over the next five years. Additional W-87s will be placed in the "inactive" stockpile, available to replace those on the deployed missiles or to be put on any newly constructed rockets.

Meanwhile, plans are going forward to start similar refurbishment for the W-76 warheads carried by the Trident I sub-launched intercontinental missile; the W-80 warhead for sea- and ground-launched cruise missiles; and the W-88, the newest and most miniaturized U.S. warhead, carried by the Trident II sub-launched ICBM.

While adhering to a pledge made by President George Bush not to resume underground nuclear testing, the Energy Department also has a backup plan to resume such testing within three years if needed. One official said last week that the time frame could be shortened "to months" for limited testing.

Energy already is planning to step up the number of "subcritical tests"--tiny, contained explosions that do not involve an uncontrolled nuclear chain reaction but do allow scientists to study how nuclear materials react to explosive force--from four last year to seven this year.

Essentials of Post-Cold War Deterrence
from "Backing Up Globalization with Military Might"
CovertAction Quarterly
Fall/Winter 1999
by Karen Talbot
citing a story by Linda Diebel
Toronto Star
July 23, 1999

Nothing could describe U.S. military goals better than the British American Security Information Council's recently published, partially declassified, text of the U.S. Strategic Command's 1995 Essentials of Post-Cold War Deterrence:

"[T]he United States should have available the full range of responses, conventional weapons, special operations, and nuclear weapons. Unlike chemical or biological weapons, the extreme destruction from a nuclear explosion is immediate, with few if any palliatives to reduce its effect. Although we are not likely to use nuclear weapons in less than matters of the greatest national importance. Nuclear weapons always cast a shadow over any crisis or conflict in which the U.S. is engaged. Thus, deterrence through the threat of use of nuclear weapons will continue to be our top military strategy...

"That the U.S. may become irrational and vindictive if its vital interests are attacked should be a part of the national persona we project to all adversaries..."

US, Russia Sign Missile Agreement
Saturday December 16 6:21 AM ET

BRUSSELS, Belgium (AP) - Secretary of State Madeleine Albright and Russian Foreign Minister Igor Ivanov signed an agreement Saturday aimed at strengthening cooperation on preventing accidental missile launches on both sides.

The new agreement comes as an update to an initial early warning system set up last year by President Clinton and Russian President Vladimir Putin to prevent accidental launches. The updated pact looks to expand a joint warning center where the sides can exchange information, officials said.

``The result will be deeper confidence and greater strategic stability between our two nations, which translates into a safer and more secure world,'' Albright said after the signing.

Ivanov told reporters that other nuclear powers will be invited to join the agreement. He said such cooperation benefits everyone, not just the two former Cold War adversaries.

``All these efforts are aimed at strengthening strategic stability,'' he said.

Cooperation on preventing accidental missile launches began after a near-launch of a nuclear counterstrike in 1995, when Russia mistook a harmless weather rocket fired from Norway for a NATO missile.

Albright and Ivanov used their breakfast meeting Saturday to discuss a wide range of issues in what might be their last bilateral face-to-face meeting before the Clinton administration makes way for President-elect George W. Bush. Topics ranging from the situation in the Balkans to arms sales to Iran were on the agenda.

Two weeks ago, Russia unilaterally walked away from a 1995 agreement with the United States that barred Moscow from making new weapons deals with Iran. No agreement was reached on that issue Saturday.

Albright's visit to Europe is part of what could be her last big trip as secretary of state. She attended a NATO foreign ministers meeting on Thursday and Friday and spent the early part of the week in Africa and Hungary.

Secret Nuke Documents Made Public
Associated Press
posted on Yahoo
January 22, 2000

WASHINGTON (AP) - The government's aggressive push five years ago to declassify historic papers led to about 1,000 documents containing nuclear weapons secrets to be mistakenly declassified, the Clinton administration told Congress.

While the nuclear weapons documents were inadvertently opened to researchers, only one of the files - on nuclear weapons deployment in foreign countries in the 1950s - was actually examined by any outsiders before the mistakes were discovered, the Department of Energy said in a report.

The papers were among millions of pages that were declassified between 1995 and 1998 under an executive order from President Clinton directing federal agencies to lift the veil of secrecy from documents that are more than 25 years old.

The openness campaign was widely applauded as an effort to reverse decades of secrecy about the nuclear weapons programs at the old Atomic Energy Commission and about a variety of events from the Vietnam War and UFO research to the failed Bay of Pigs invasion of Cuba.

The declassification effort is expected to cover about a billion pages before it is completed in a few years.

The classified report sent to Congress just before Christmas details the findings of a DOE audit of some 948,000 pages of nuclear weapons related documents that had been part of the three-year declassification effort.

During the review, auditors found that 14,890 pages containing secret weapons information were mistakenly declassified and made available for public view at the National Archives, according to an unclassified summary of the report.

The material covers ``about 1,000 documents,'' many of which originated in the old Atomic Energy Commission but had been transferred to other agencies and declassified there, said a DOE official, who spoke on condition of not being identified further.

Although none was declassified by the Energy Department, the mistakes were found in DOE audits of the declassification process required by a law passed by Congress in 1998.

Included among the 14,890 pages was information on nuclear bomb tests in the 1950s and 1960s ``that provided insight ... in weapons design technology'' as well as yields on specific weapon and their deployment and storage, according to the unclassified summary.

In a letter accompanying the report, Energy Secretary Bill Richardson cited ``the gravity of these inadvertent releases'' and said he was increasing the number of auditors and expanding training programs for those conducting declassification at the other agencies.

While the documents contained information that was in some cases 30 to 40 years old, the report said it still could be useful to someone seeking to build a crude nuclear device.

Such information, because it is technically less sophisticated, ``can provide useful design parameters to emerging (nuclear) proliferant nations and to terrorist groups,'' the department said.

The documents were erroneously declassified for a variety of reasons, the DOE official said. In some cases, reviewers were not adequately trained and did not recognize the material. In other cases, documents dating back decades were misfiled or incorrectly labeled.

Steven Aftergood, who directs the Project on Government Secrecy at the Federation of American Scientists, said that while the government should pursue ``a vigorous and successful declassification program, nobody wants to see sensitive nuclear weapons information disclosed.''

He said the fact that DOE is conducting audits that discovered the declassification mistakes ``suggests the DOE is finding a balance which will allow declassification to proceed without risking unintentional disclosure.''

Aftergood's organization obtained a copy of the unclassified portions of the DOE report to Congress and made it available.

What is the difference between atomic, nuclear, and thermonuclear weapons?
Nuclear Q & A webpage
Bulletin of the Atomic Scientists

Nuclear is a general term for weapons that release energy from nuclear reactions. Atomic refers to the earliest and least sophisticated weapons, which use nuclear fission. This occurs when neutrons bombard the nuclei of heavy elements, such as uranium and plutonium, and the nuclei split, releasing energy and more neutrons, which split still more nuclei. Atomic was the exclusive term until sometime during the Eisenhower administration; Ike said it 31 times in his "Atoms For Peace" address to the United Nations in 1953, but he split the difference in 1957, when a memo with the subject line "Policy regarding use of atomic weapons" accompanied his "Authorization for the Expenditure of Nuclear Weapons." However, by 1962 JFK was talking about nuclear--not atomic--warheads in the captive land of Cuba, and atomic was relegated largely to 1940s and 1950s holdouts, such as the International Atomic Energy Agency and certain bimonthly publications.

The United States tested the first thermonuclear devices in 1952; also called fusion or hydrogen bombs, these use nuclear fusion, which results when the nuclei of hydrogen isotopes merge and release energy. Fusion takes place only at very high temperatures, so thermonuclear devices first set off a fission reaction, which triggers the fusion; some weapons have two fusion stages, the first initiating the second. Thermonuclear devices are much more powerful than fission bombs: the biggest American warhead, the B83, has a yield of 1,200 kilotons, more than 57 times larger than the 21 kilotons of Fat Man, the bomb dropped on Nagasaki.

What happened to all those fallout shelters?
Nuclear Q & A webpage
Bulletin of the Atomic Scientists

Fallout shelters no longer are the status symbol they were in the 1960s, when President Kennedy urged "a fallout shelter for everyone as rapidly as possible." Detente, arms agreements, and, later, the implosion of the Soviet Union put an end to what once had been a growth industry. In 1992, the U.S. Federal Trade Commission dispensed with its rules governing advertising for fallout shelters, including the prohibition of "scare tactics, such as the employment of horror pictures calculated to arouse unduly the emotions of prospective shelter buyers." An era had come to a close.

Still, many backyard fallout shelters remain. People just are finding other uses for them. Last year USA Today reported that a Chicago peace activist uses hers as the local office of a project to wrap the Pentagon in fabric (on the anniversary of Hiroshima, appropriately enough), and a downstate Illinois tax lawyer turned his into a wine cellar. One shelter is even a museum piece: in 1994, the Smithsonian's National Museum of American History unveiled a permanent exhibition of an all-steel shelter, donated by Vera Howey of Fort Wayne, Indiana. A Smithsonian article accompanying the debut notes that it was one of six shelters an enterprising Hoosier sold for $1,800 apiece in the 1950s. It came equipped with a chemical toilet and a hand-cranked air pump. The museum outfitted it with canned goods and 1950s board games for that period feel.

And the shelter movement lives! At its on-line store the American Civil Defense Association sells the Hive, a polyethylene underground shelter. Competitively priced at $1,749, with a five-year limited warranty, the Hive may be stocked with one of the Association's survival food packages. The Cadillac of calamity pantries, the YRT-1, contains 120 cans of fruits, vegetables, grains, and "soups and gravies," which provide 1,750 balanced calories per day for one year--a steal at $1,596, plus freight from Montana ($1,571 for association members).

Types of Nuclear Weapons
Nuclear Weapons Frequently Asked Questions
By Carey Sublette
Version 2.16, dated 1 May 1998
from the Federation of American Scientists FAQ site

Nuclear weapons can be grouped into different classes based on the nuclear reactions that provide their destructive energy, and on the details of their design. The popular division of nuclear weapons into fission bombs and fusion bombs is not entirely satisfactory. The spectrum of weapon design is more complex than this simple classification implies. All nuclear weapons so far invented require fission to initiate the explosive release of energy. Weapons that incorporate fusion fuel can do so in various ways, with different intended effects. This section attempts to survey the basic types of bomb designs systematically. More detailed discussions of the physics and design principles of each type will be covered in more detail in later sections.

1.1 Terminology

A variety of names are used for weapons that release energy through nuclear reactions - atomic bombs (A-bombs), hydrogen bombs (H-bombs), nuclear weapons, fission bombs, fusion bombs, thermonuclear weapons (not to mention "physics package" and "device"). A few comments about terminology is probably in order.

The earliest name for such a weapon appears to be "atomic bomb". This has been criticized as a misnomer since all chemical explosives generate energy from reactions between atoms - that is, between intact atoms consisting of both the atomic nucleus and electron shells. Further the fission weapon to which "atomic bomb" is applied is no more "atomic" than fusion weapons are. However the name is firmly attached to the pure fission weapon, and well accepted by historians, the public, and by the scientists who created the first nuclear weapons.

Since the distinguishing feature of both fission and fusion weapons is that they release energy from transformations of the atomic nucleus, the best general term for all types of these explosive devices is "nuclear weapon" (hence the name of this FAQ).

Fusion weapons are called "hydrogen bombs" (H-bombs) because isotopes of hydrogen are principal components of the nuclear reactions involved. In fact, in the earliest fusion bomb designs deuterium (hydrogen-2) was the sole fusion fuel. Fusion weapons are called "thermonuclear weapons" because high temperatures are required for the fusion reactions to occur.

1.2 Nuclear Test Names

Before discussing U.S. nuclear tests, the designation system used to identify the tests and each bomb that is tested should be clarified. Each test bomb has a code name that identifies it, the actual test has another code name. Thus the first atomic bomb was called Gadget, and it was tested in operation Trinity.

The early test operations were conducted as part of a test series, a large scale operation where many scientists, support technicians, military personnel, etc. assemble in order to set off and observe a number of devices over several weeks or months. This test series has another code name. For example the second and third test explosions of nuclear weapons (which were the fourth and fifth nuclear explosions of course) were part of the Crossroads test series. The two tests were designated Able and Baker. Sometimes the U.S. conducted two sequences of tests for different purposes jointly as a single series. When this occurred the name for each sequence was combined to form the name of the entire series (e.g. Tumbler-Snapper).

In the early test series, the same test names were reused several times. Thus there was an Able test in the Crossroads, Ranger, Buster-Jangle, and Tumbler-Snapper test series. To unambiguously identify each test the convention is to list the series code name, followed by the test name: Crossroads Able, Ranger Able, and so on. After mid-1952 unique test names began to be used, so that this convention was no longer strictly necessary. However it is useful to specify the series as well, so I have adopted the general practice of identifying tests by the series-test combination.

After 1961 the test series system was dropped as underground testing in Nevada became routine, all of which are usually considered part of the Nevada Series. Actually these tests are also still designated as being part of specific test series, but now each "series" simply corresponds to a government fiscal year (Operation Niblick is FY64, Operation Whetstone is FY65, etc.) and loses any real meaning. There was a final series of open air testing in the Pacific (the Pacific Series: Dominic I and Dominic II)in 1962, and a few special test programs (Plowshare, Vela Uniform Seismic Detonation). For Nevada Series tests after 1961, and all U.S. tests after 1963, I often follow the common practice of simply identifying them by their test names.

The code names of the actual devices are generally not well known. Many remained classified until recently (or still are). Since a bomb can only be tested once, identifying the device by the test in which it was detonated is unambiguous. In the open literature the test name has usually been used to designate the bomb that was tested, a convention followed here as well.

British tests follow a similar nomenclature but are not as systematic. Except for the first test (Hurricane), each test has both a series and test identifier. Sometimes the test identifier alone is unique, sometimes not. A variety of test series qualifiers may be attached to the series name (different from the actual test name), but the pattern for doing so is unclear. For example the Grapple series included the test Grapple 1/Short Granite (with Grapple 1 by itself uniquely identifying the test), but multiple tests all with the series designation Grapple Z. As with U.S. tests, both full series and test name designations will be given.

1.3 Units of Measurement

As a general rule I try to use the metric system throughout this FAQ. Units belonging to the U.S. Customary measurement system will crop up periodically since the primary sources of information about nuclear weapons in general are from the United States and I have not tried to convert all measurements from U.S. sources to metric yet. This presents certain problems when approximate or rounded numbers are given - should "50 lb" be rendered "22.7 kg" (falsely implying 3 digit precision) or should it be "25 kg" (and changing the measurement by 13%)?

There is also the problem of which "metric" system to use. The metric system was invented in the Napoleonic era and an international standards body has existed since 1875. Over the last two centuries many metric units had come into use, with many variations by nationality and discipline. In 1960 the SI system (Le Systeme International d'Unites) was adopted - a thoroughgoing effort to clean-up and regularize the mess that had accumulated. Many of the units that came into use early in the atomic age - curies, rems, rads, roentgens, barns, fermis, etc. - were eliminated. These units are outside the SI system, but are recognized by the SI standards as anciliary metric units to be discouraged and eventually phased out. However the original historical and scientific documents regarding the atomic age, and most writings about it since, are completely dominated by these non-SI units. Accordingly I have made no attempt to keep to the SI system.

A continuing source of confusion with nuclear weapons is the meaning of the word "ton". Normally this is used as a unit of mass or weight (a distinction I am going to ignore) in either the Metric, British Imperial, or U.S. Customary measurement systems (the last two both having two types of tons, short and long). In connection with nuclear weapons the term "ton" and its metric extensions (kiloton, megaton, etc.) are also used as units of explosive energy output or yield. The confusion is further heightened by the non-standard convention sometimes employed in the U.S. or Britain of using the abbreviation MT (or Mt, or mt) to distinguish metric tons from short tons, while also using MT (or Mt, or mt) to mean "megaton".

The SI system does not use the ton, but it does recognize a metric unit of 1000 kg called the "tonne" (aka the metric ton). In this FAQ I use tonne to mean metric ton. Ton is used either to refer to the U.S./Imperial short ton, or for the energy yield of small explosions. Which is which should be apparent from context.

Now the units of explosive energy (megatons, kilotons, or even just tons, depending on yield) are derived from attempts to compare the explosive force of a bomb to conventional explosives, the original intention was to equate it with tons of trinitrotoluene (TNT) - a workhorse military explosive. This presented problems very quickly. To which "tons" does the comparison refer? And the explosive force of TNT is not exactly a universal constant. The energy release is affected by such things as charge density, degree of confinement, temperature, and the reference end state of the explosion products. Energy outputs ranging over 980-1100 calories/g are reported.

To clarify the situation kilotons (megatons, etc.) were redefined to be a metric unit equal to exactly 1012 calories (4.186x1012 joules). Thus treating kilotons as a metric mass measurement (kilotonnes) of TNT gives a value of 1000 c/g, well within the reported range, while treating it as "kilo short tons of TNT" gives 1102 c/g, at the extreme upper end of the reported range. Thus a kiloton can be called a "kilo metric ton of TNT" and a "kilo short ton of TNT" with about equal validity.

Note that the metric definition of kiloton refers to ALL of the energy immediately released by the device, regardless of form. Although chemical explosives release essentially all of their energy as kinetic or blast energy, only part of the energy in a nuclear explosion is released in this form (though under most conditions, it is the major part). Thus a kiloton nuclear explosion actually has significantly less blast effect than a kiloton chemical explosion.

The proper capitalization of the abbreviations for kiloton and megaton is also non-standard. kt, kt, kT, and KT can all be found in the literature (the authoritative Effects of Nuclear Weapons avoids the issue by never abbreviating these terms). The SI standards guide recognizes the use of a lower case "t" for tonne, but no capitalization rule has ever been adopted for the explosive ton. The official SI capitalization rule for kilo is "k" and for mega it is "M" (I think it would have been more logical to reserve lower case letters for metric scale fractional units - deci, centi, milli, etc., while reserving upper case for multiple units - deka, kilo, mega, etc., but SI doesn't do this).

For no particular reason I use the lower case "t" for the explosive yield measurement ton, and I follow the SI standard in metric scale abbreviations thus we have kt and Mt for kiloton and megaton.

1.4 Pure Fission Weapons

These are weapons that only use fission reactions as a source of energy. Fission bombs operate by rapidly assembling a subcritical configuration of fissile material (plutonium or enriched uranium) into one that is highly supercritical. The original atomic bombs tested in 16 July 1945 (device name: Gadget, test name: Trinity) and dropped on Japan in 6 August 1945 (Little Boy, over Hiroshima) and 9 August 1945 (Fat Man, over Nagasaki) were pure fission weapons.

These are the easiest nuclear weapons to design and manufacture, and the capability to do so is a prerequisite for developing any of the other weapon types. In addition to the five declared nuclear powers (the U.S., the USSR/Russia, Britain, France, and China) which have all acquired and tested these weapons, they have also been acquired by Israel, India, South Africa, and Pakistan. India has tested a fission bomb, while Israel and South Africa are suspected of having tested one.

There are practical limits to the size of pure fission bombs. Larger bombs require more fissionable material, which:

  1. becomes increasingly difficult to maintain as a subcritical mass before detonation and
  2. makes it harder to assemble into a high efficiency supercritical mass before stray neutrons cause predetonation.

Due to secrecy, and the boosting issue described below, it is somewhat difficult to identify the largest pure fission bomb ever tested for certain. It appears to have been the 500 kt Ivy King test by the U.S. (15 November 1952). The device exploded in this test was the Mk-18 Super Oralloy Bomb ("SOB") designed by a team led by Ted Taylor.

1.5 Combined Fission/Fusion Weapons

All nuclear weapons that are not pure fission weapons use fusion reactions to enhance their destructive effects. All weapons that use fusion require a fission bomb to provide the energy to initiate the fusion reactions. This does not necessarily mean that fusion generates a significant amount of the explosive energy, or that explosive force is even the desired effect.

1.5.1 Boosted Fission Weapons

The earliest application of fusion to useful weapons was the development of boosted fission weapons. In these weapons a few grams of a deuterium/tritium gas mixture are included in the center of the fissile core. When the bomb core undergoes enough fission, it becomes hot enough to ignite the D-T fusion reaction which proceeds swiftly. This reaction produces an intense burst of high-energy neutrons that causes a correspondingly intense burst of fissions in the core. This greatly accelerates the fission rate in the core, thus allowing a much higher percentage of the material in the core to fission before it blows apart. Typically no more than about 20% of the material in an average size pure fission bomb will split before the reaction ends (it can be much lower, the Hiroshima bomb was 1.4% efficient). By accelerating the fission process a boosted fission bomb increase the yield 100% (an unboosted 20 kt bomb can thus become a 40 kt bomb). The actual amount of energy released by the fusion reaction is negligible, about 1% of the bomb's yield, making boosted bomb tests difficult to distinguish from pure fission tests (detecting traces of tritium is about the only way).

The first boosted weapon test was Greenhouse Item (45.5 kt, 24 May 1951), an oralloy design exploded on island Janet at Enewetak. This experimental device used cryogenic liquid deuterium-tritium instead of gas. The boosting approximately doubled the yield over the expected unboosted value. Variants on the basic boosting approach that have been tested including the use of deuterium gas only, and the use of lithium deuteride/tritide, but it isn't known whether any of these approaches have been used in operational weapons.

Due to the marked increase in yield (as well as other reasons - such as reducing the weight of the fission system, and eliminating the risk of predetonation) today most fission bombs are boosted, including those used as primaries in true fission-fusion weapons. Although boosting can multiply the yield of fission bombs, it still has the same fundamental fission bomb design problems for high yield designs. The boosting technique is most valuable in small light-weight bombs that would otherwise have low efficiency. Tritium is a very expensive material to make, and it decays at a rate of 5.5% per year, but the small amounts required for boosting (a few grams) make its use economical.

1.5.2 Staged Radiation Implosion Weapons

This class of weapons is also called "Teller-Ulam" weapons, or (depending on type) fission-fusion or fission-fusion-fission weapons. These weapons use fusion reactions involving isotopes of light elements (e.g. hydrogen and lithium) to remove the yield limits of fission and boosted fission designs, to reduce weapon cost by reducing the amount of costly enriched uranium or plutonium required for a given yield, and to reduce the weight of the bomb. The fusion reactions occur in a package of fusion fuel ("the secondary") that is physically separate from the fission trigger ("the primary"), thus creating a two-stage bomb (the fission primary counting as the first stage). X-rays from the primary are used to compress the secondary through a process known as radiation implosion. The secondary is then ignited by a fission "spark plug" in its center. The energy produced by the fusion second stage can be used to ignite an even larger fusion third stage. Multiple staging allows in principle the creation of bombs of virtually unlimited size.

The fusion reactions are used to boost the yield in two ways:

  1. By directly releasing a large amount of energy in fusion reactions;
  2. By using high-energy or "fast" neutrons generated by fusion to release energy through fissioning of a fissionable jacket around the fusion stage. In the past this jacket was often made of natural or depleted uranium, so that energy is produced by fast fission of cheap U-238. Thorium may also be used for this purpose, although it is inferior to cheap and abundant depleted uranium. Weapons in which there is a premium on weight and size (i.e. virtually all modern strategic weapons) use moderately to highly enriched uranium as the jacketing material.

Bombs that release a significant amount of energy directly by fusion, but do not use fusion neutrons to fission the fusion stage jacket, are called Fission-Fusion weapons. If they employ the additional step of jacket fissioning using fusion neutrons they are called Fission-Fusion-Fission weapons.

The fast fission of the secondary jacket in a fission-fusion-fission bomb is sometimes thought of, or referred to, as a "third stage" in the bomb, and it is in a sense. But care must be taken not to confuse this with the true three-stage thermonuclear design in which there is another complete tertiary fusion stage.

Bombs that are billed as "clean" bombs (a relative term) obtain a large majority of their total yield from fusion. The last and largest stage of these bombs is always a pure fusion stage (not counting the spark plug), substituting a non-fissionable material for the jacket. The fusion-fraction of these designs as demonstrated in tests has been as high as 97% (this was the Tsar Bomba, see below).

Fission-fusion-fission bomb are dirty, but they have superior "bang for the buck" and "pow per pound". They generate a large amount of fission fallout since fission accounts for most of their yield. The 5 Mt Redwing Tewa test (20 July 1956 GMT, Bikini Atoll) had a fission fraction of 85%. If the emphasis is on cheapness depleted or natural uranium is usually used for the jacket. If the emphasis is on yield per weight (like nearly all modern strategic weapons) enriched uranium is used.

The staging concept allows the use as fuel pure deuterium, or varying mixtures of lithium 6 and 7 in the form of a compound with deuterium (lithium 6/7 deuteride). These natural stable isotopes are vastly cheaper than the artificially made and radioactive tritium.

The staged radiation implosion concept was originally conceived by Stanislaw Ulam and then developed further in a collaboration between Ulam and Edward Teller in early 1950. The first test of a staged thermonuclear device was Ivy Mike on 31 October 1952 (GMT) on Elugelab/Flora island at Enewetak Atoll. This experimental device, called Sausage, used pure deuterium fuel (probably the only time this was ever done) and a natural uranium jacket. It was designed by the Panda Committee led by J. Carson Mark at Los Alamos. Mike a yield of 10.4 Mt, 77% of which was fission.

The Teller-Ulam concept was later rediscovered by the other four nuclear weapon states, all of which have tested and deployed these weapons. No other nation is known to have deployed these designs, although the undeclared nuclear powers of Israel and India almost certainly have done development work on them.

Three stage designs have been tested and deployed to produce very high yield weapons. The first three stage U.S. test, and probably the first three stage weapon test ever, was the Bassoon device detonated in the Redwing Zuni test (27 May 1956 GMT, Bikini Atoll, 3.5 Mt). The largest nuclear explosion ever set off (50 Mt) was the Tsar Bomba (King of Bombs), a Soviet three stage fission-fusion-fission design. It was exploded on 30 October 1961 over Novaya Zemlya at an altitude of 4000 m.

By jacketing the third stage with non-fissionable material, three stage devices can produce high yield clean weapons. Both Zuni and Tsar Bomba were in fact very clean devices - Zuni was 85% fusion and Tsar Bomba was 97% fusion. Both designs permitted replacing the lead or tungsten third stage jacket with U-238 however. A version of Bassoon called Bassoon Prime was tested in the dirty Tewa test mentioned above. A dirty device derived from the Bassoon was weaponized to create the highest yield weapon the U.S. ever fielded, the 25 megaton Mk-41. The Tsar Bomba design was for a fission-fusion-fission bomb with a staggering yield of at least 100 megatons!

A possible variation on the staged radiation implosion design is one in which a second fission stage is imploded instead of a thermonuclear one. This was actually the initial concept developed by Stanislaw Ulam before he realized its possible application to thermnuclear weapons. The advantage of this approach is that radiation implosion speeds are hundreds of times higher, and maximum densities tens of times greater, than those achievable through high explosives. This allows achieving higher yields than is practical with high explosive driven fission weapons, and the use of lower grades of fissile material. If some fusion fuel is included in this second fission stage to boost yield, a sort of hybrid two-stage boosted weapon design results that blurs the distinction between two-stage fission and classic Teller-Ulam thermonuclear weapons. The TX-15 "Zombie" developed by the U.S. was originally planned to be a two stage pure fission device, but later evolved into this sort of hybrid boosted system. The Zombie was tested in the Castle Nectar shot (13 May 1954 GMT; Bikini Atoll; 1.69 Mt), and was fielded as the Mk-15.

1.5.3 The Alarm Clock/Sloika (Layer Cake) Design

This idea predates the invention of staged radiation implosion designs, and was apparently invented independently at least three times. It was first devised by Edward Teller in the United States, who named the design "Alarm Clock". Later Andrei Sakharov and Vitalii Ginzburg in the Soviet Union hit upon it and dubbed it the "sloika" design. A sloika is a layered Russian pastry, rather like a napoleon, and has thus been translated as "Layer Cake". Finally it was developed by the British (inventor unknown). Each of these weapons research programs hit upon this idea before ultimately arriving at the more difficult, but more powerful and efficient, staged thermonuclear approach.

This system was dubbed "Layer Cake" by the Soviets because it uses a spherical assembly of concentric shells. In the center is a fission primary made of U-235/Pu-239, surrounding it is an (optional) layer of U-238 for the fission tamper, then a layer of lithium-6 deuteride/tritide, a U-238 fusion tamper, and finally the high explosive implosion system. The process begins like an ordinary implosion bomb. After the primary in the center completes its reaction, the energy it releases compresses and heats the fusion layer to thermonuclear temperatures. The burst of fission neutrons then initiates a coupled fission-fusion-fission chain reaction. Slower fission neutrons generate tritium from the lithium, which then fuses with deuterium to produce very fast neutrons, that in turn cause fast fission in the fusion tamper, which breed more tritium. In effect the fusion fuel acted as a neutron accelerator allowing a fission chain reaction to occur with a large normally non-fissionable U-238 mass. While spiking the fusion layer with an initial dose of tritium is not strictly necessary for this approach, it helps boost the yield.

The achievable fusion fraction is fairly small, 15-20%, and cannot be increased beyond this point. Its use of fusion fuel is also quite inefficient. This design is also limited to the same yield and yield-to-weight range as high yield pure fission and boosted fission weapons. This was developed into a deliverable weapon by the Soviet Union and the British prior to their development of the staged designs described above. The U.S. did not bother to pursue it, partly because Teller did not feel it was sufficiently destructive to be worthwhile.

The first test of this concept was a device designated RDS-6s, (known as Joe 4 to the U.S.) on 12 August 1953. By using tritium doping it achieved a 10-fold boost over the size of the trigger, for a total yield of 400 kt. The UK Orange Herald Small device tested in Grapple 2 (31 May 1957) was similar but used a much larger fission trigger (300 kt range) apparently without tritium for a total yield of 720 kt, a boost in the order of 2.5-fold. This is probably the largest test of this design.

Although apparently not used in any weapons now in service in the five declared weapons states, it remains a viable design that could be attractive to other states that do not have the resources to develop the technically more demanding radiation implosion design. Information supplied by Mordechai Vanunu indicates that Israel may have developed a weapon of this type.

This design should probably be considered distinct from other classes of nuclear weapons. This design is something of a hybrid and could be considered either a type of boosted fission device, or a one-stage type of fission-fusion-fission bomb.

1.5.4 Neutron Bombs

Neutron bombs, more formally referred to as "enhanced radiation (ER) warheads", are small thermonuclear weapons in which the burst of neutrons generated by the fusion reaction is intentionally not absorbed inside the weapon, but allowed to escape. This intense burst of high-energy neutrons is the principle destructive mechanism. Neutrons are more penetrating than other types of radiation so many shielding materials that work well against gamma rays do not work nearly as well. The term "enhanced radiation" refers only to the burst of ionizing radiation released at the moment of detonation, not to any enhancement of residual radiation in fallout.

The U.S. has developed neutron bombs for use as strategic anti-missile weapons, and as tactical weapons intended for use against armored forces. As an anti-missile weapon ER weapons were developed to protect U.S. ICBM silos from incoming Soviet warheads by damaging the nuclear components of the incoming warhead with the intense neutron flux. Tactical neutron bombs are primarily intended to kill soldiers who are protected by armor. Armored vehicles are extremely resistant to blast and heat produced by nuclear weapons, so the effective range of a nuclear weapon against tanks is determined by the lethal range of the radiation, although this is also reduced by the armor. By emitting large amounts of lethal radiation of the most penetrating kind, ER warheads maximize the lethal range of a given yield of nuclear warhead against armored targets.

One problem with using radiation as a tactical anti-personnel weapon is that to bring about rapid incapacitation of the target, a radiation dose that is many times the lethal level must be administered. A radiation dose of 600 rads is normally considered lethal (it will kill at least half of those who are exposed to it), but no effect is noticeable for several hours. Neutron bombs were intended to deliver a dose of 8000 rads to produce immediate and permanent incapacitation. A 1 kt ER warhead can do this to a T-72 tank crew at a range of 690 m, compared to 360 m for a pure fission bomb. For a "mere" 600 rad dose the distances are 1100 m and 700 m respectively, and for unprotected soldiers 600 rad exposures occur at 1350 m and 900 m. The lethal range for tactical neutron bombs exceeds the lethal range for blast and heat even for unprotected troops.

The neutron flux can induce significant amounts of short lived secondary radioactivity in the environment in the high flux region near the burst point. The alloy steels used in armor can develop radioactivity that is dangerous for 24-48 hours. If a tank exposed to a 1 kt neutron bomb at 690 m (the effective range for immediate crew incapacitation) is immediately occupied by a new crew, they will receive a lethal dose of radiation within 24 hours.

Newer armor designs afford more protection than the Soviet T-72 against with ER warheads were initially targeted. Special neutron absorbing armor techniques have also been developed and deployed, such as armors containing boronated plastics and the use of vehicle fuel as a shield. Some newer types of armor, like that of the M-1 tank, employ depleted uranium which can offset these improvements since it undergoes fast fission, generating additional neutrons and becoming radioactive.

Due to the rapid attenuation of neutron energy by the atmosphere (it drops by a factor of 10 every 500 m in addition to the effects of spreading) ER weapons are only effective at short ranges, and thus are found in relatively low yields. ER warheads are also designed to minimize the amount of fission energy and blast effect produced relative to the neutron yield. The principal reason for this was to allow their use close to friendly forces. The common perception of the neutron bomb as a "landlord bomb" that would kill people but leave buildings undamaged is greatly overstated. At the intended effective combat range (690 m) the blast from a 1 kt neutron bomb will destroy or damage to the point of unusability almost any civilian building. Thus the use of neutron bombs to stop an enemy attack, which requires exploding large numbers of them to blanket the enemy forces, would also destroy all buildings in the area.

Neutron bombs (the tactical versions at least) differ from other thermonuclear weapons in that a deuterium-tritium gas mixture is the only fusion fuel. The reasons are two-fold: the D-T thermonuclear reaction releases 80% of its energy as neutron kinetic energy, and it is also the easiest of all fusion reactions to ignite. This means that only 20% of the fusion energy is available for blast and thermal radiaiton production, that the neutron flux produced consists of extremely penetrating 14.7 Mev neutrons, and that a very small fission explosion (250-400 tons) can be used for igniting the reaction. The more typical lithium deuteride fuel would produce much more blast and flash for each unit of neutron flux, and would require a much larger fission explosion to set it off. The disadvantage of using D-T fuel is that tritium is very expensive, and decays at a rate of 5.5% a year. Combined with its increased complexity this makes ER warheads more expensive to build and maintain than other tactical nuclear weapons. To produce a 1 kt fusion yield 12.5 g of tritium and 5 g of deuterium are required.

The U.S. developed and produced three neutron warheads, a fourth was cancelled prior to production. All have been retired and dismantled.

The Soviet Union, China, and France are all known to have developed neutron bomb designs and may have them in service. A number of reports have claimed that Israel has developed neutron bombs which, though they could be valuable on an armor battleground like the Golan Heights, are difficult to develop and require sigificant testing. This makes it unlikely that Israel has in fact acquired them.

1.6 Cobalt Bombs and other Salted Bombs

A "salted" nuclear weapon is reminiscent of fission-fusion-fission weapons, but instead of a fissionable jacket around the secondary stage fusion fuel, a non-fissionable blanket of a specially chosen salting isotope is used (cobalt-59 in the case of the cobalt bomb). This blanket captures the escaping fusion neutrons to breed a radioactive isotope that maximizes the fallout hazard from the weapon rather than generating additional explosive force (and dangerous fission fallout) from fast fission of U-238.

Variable fallout effects can be obtained by using different salting isotopes. Gold has been proposed for short-term fallout (days), tantalum and zinc for fallout of intermediate duration (months), and cobalt for long term contamination (years). To be useful for salting, the parent isotopes must be abundant in the natural element, and the neutron-bred radioactive product must be a strong emitter of penetrating gamma rays.

Table 1.6-1 Candidate Salting Agents

Parent        Natural   Radioactive  Half-Life 
Isotope      Abundance    Product

Cobalt-59     100%        Co-60      5.26 years
Gold-197      100%        Au-198     2.697 days
Tantalum-181   99.99%     Ta-182     115 days
Zinc-64        48.89%     Zn-65      244 days

The idea of the cobalt bomb originated with Leo Szilard who publicized it in Feb. 1950, not as a serious proposal for weapon, but to point out that it would soon be possible in principle to build a weapon that could kill everybody on earth (see Doomsday Device in Questions and Answers). To design such a theoretical weapon a radioactive isotope is needed that can be dispersed world wide before it decays. Such dispersal takes many months to a few years so the half-life of Co-60 is ideal.

The Co-60 fallout hazard is greater than the fission products from a U-238 blanket because

  1. many fission-produced isotopes have half-lives that are very short, and thus decay before the fallout settles or can be protected against by short-term sheltering;
  2. many fission-produced isotopes have very long half-lives and thus do not produce very intense radiation;
  3. the fission products are not radioactive at all. The half-life of Co-60 on the other hand is long enough to settle out before significant decay has occurred, and to make it impractical to wait out in shelters, yet is short enough that intense radiation is produced.

    Initially gamma radiation fission products from an equivalent size fission-fusion-fission bomb are much more intense than Co-60: 15,000 times more intense at 1 hour; 35 times more intense at 1 week; 5 times more intense at 1 month; and about equal at 6 months. Thereafter fission drops off rapidly so that Co-60 fallout is 8 times more intense than fission at 1 year and 150 times more intense at 5 years. The very long lived isotopes produced by fission would overtake the again Co-60 after about 75 years.

    Zinc has been proposed as an alternate candidate for the "doomsday role". The advantage of Zn-64 is that its faster decay leads to greater initial intensity. Disadvantages are that since it makes up only half of natural zinc, it must either be isotopically enriched or the yield will be cut in half; that it is a weaker gamma emitter than Co-60, putting out only one-fourth as many gammas for the same molar quantity; and that substantially amounts will decay during the world-wide dispersal process. Assuming pure Zn-64 is used, the radiation intensity of Zn-65 would initially be twice as much as Co-60. This would decline to being equal in 8 months, in 5 years Co-60 would be 110 times as intense.

    Militarily useful radiological weapons would use local (as opposed to world-wide) contamination, and high initial intensities for rapid effects. Prolonged contamination is also undesirable. In this light Zn-64 is possibly better suited to military applications than cobalt, but probably inferior to tantalum or gold. As noted above ordinary "dirty" fusion-fission bombs have very high initial radiation intensities and must also be considered radiological weapons.

    No cobalt or other salted bomb has ever been atmospherically tested, and as far as is publicly known none have ever been built. In light of the ready availability of fission-fusion-fission bombs, it is unlikely any special-purpose fallout contamination weapon will ever be developed.

    The British did test a bomb that incorporated cobalt as an experimental radiochemical tracer (Antler/Round 1, 14 September 1957). This 1 kt device was exploded at the Tadje site, Maralinga range, Australia. The experiment was regarded as a failure and not repeated.

    How many nuclear devices are there in space?
    Nuclear Q & A webpage
    Bulletin of the Atomic Scientists

    There are more than 75 nuclear devices in space, 38 of them American and 37 belonging to Russia. Forty-six of these devices are in orbit around the Earth, 12 remain on the moon and Mars, and 17 are aboard deep space probes.

    Nuclear devices are an attractive source of energy in space because they can provide vast quantities of power in a small, lightweight, reliable package. While solar energy is sufficient for most satellites orbiting earth, deep-space and most planetary probes flying away from the sun cannot rely on its radiation for their power. There is no contest between nuclear fuel and chemical-based means of power production: in a business where launching anything is extremely costly, one kilogram of nuclear fuel can produce up to 10 million times more energy than the same amount of chemical-based batteries. Nuclear power is also attractive for military applications: a nuclear power source would be more likely than fragile solar arrays to survive any damage or radiation from explosions in space.

    For all the advantages offered by nuclear devices, there is always the threat of an accident. A total of seven rockets carrying nuclear payloads have failed to achieve orbit, and three satellites carrying nuclear payloads have accidentally re-entered earth's atmosphere. Though most of these accidents did not cause damage--the nuclear payloads remained intact, and some were even re-used on later missions--several incidents have been disturbing.

    In 1964, before the United States designed nuclear devices to survive atmospheric re-entry, an American satellite accidentally lost its orbit and re-entered the Earth's atmosphere. As it was designed to do, the satellite jettisoned its nuclear payload at a high altitude, releasing radiation over the Indian Ocean at an altitude of 75 miles. In a more serious incident in 1978, a Soviet radar reconnaissance satellite malfunctioned and crashed into the Great Slave Lake in Canada's Northwest Territory. Thousands of highly radioactive fragments were dispersed in the lake and surrounding area; the Soviets grudgingly paid for only half the clean-up cost.

    These accidents have raised fears that if some proposals for a national missile defense program were carried out, the probability for a nuclear accident would increase. Some proposed missile defense systems rely heavily on reactor-powered satellites. If implemented, activists warn, these programs would increase the danger of one or more of these satellites crashing due to failed launches and/or accidental re-entries. Also, some opponents of RTGs and other nuclear devices worry that nuclear powered deep-space devices on vessels like the Cassini probe, which use close earth orbits to "slingshot" themselves into outer space, may disintegrate in the atmosphere and spew their radioactive payloads over vast areas of the earth's surface. Scientists, however, claim that these fears are largely unfounded, and complain that public phobia of nuclear power has drastically cut funding for space exploration's most viable energy source.

    Six Seconds That Didn't Shake the World
    By Colonel Dan Smith, USA (Ret.)
    January 20, 2000

    Twenty eight minutes: that's the time the Pentagon believes is available to detect a missile launch, track and project the course of the missile, and launch a U.S. missile that has a chance of intercepting and destroying the incoming missile or its warhead.

    On January 18, for the second time in four months, that was the scenario played out high above the Pacific Ocean. This is how it was choreographed:

    A detailed analysis of exactly what caused the failure of both infrared detectors may not be available for some days or weeks. However, some things are known:

    The idea driving the current NMD development is that the U.S. must be able to deter a rogue nation from launching or, if necessary, knock down a handful of Intercontinental Ballistic Missiles fired at the United States. Considering the countries normally named in this scenario -- Iran, North Korea, and eventually Iraq, perhaps 28 minutes for NMD is a reasonable window -- if the new U.S. satellite systems are ever launched, other nations allow us to upgrade critical ground based radars, the actual NMD launch vehicle comes on line, and all the components that are part of the NMD system are successfully integrated and work as intended.

    And "work" must be for the entire 28 minutes. In the real world, anything short of that -- even six seconds -- would shake not only the U.S. but the whole world with devastating consequences.

    For Nonproliferation, Arms Control Study, One School Rules
    By Judith Miller
    New York Times
    January 13, 2000

    MONTEREY, Calif. -- In universities, as in real estate, location and timing are everything. Fortunately for Dr. William Potter, an indefatigable promoter of arms control and American-Russian cooperation, his Center for Nonproliferation Studies has enjoyed both.

    Established a decade ago as the Soviet Union was disintegrating and control over its vast stores of weapons was slipping into limbo, the center is the only place of study in the United States that offers a graduate certificate in nonproliferation.

    Begun in 1989 in two small offices in a bungalow and with a budget of $35,000, it has flourished over the past decade on the notion that by bringing together students, officials and analysts from around the globe to study weapons of mass destruction on the spectacular, secluded shores of this Northern California town, the world may become a safer place.

    Today the center has 50 staff members, 65 graduate students -- including Russians, Ukranians, Chinese, Indians and Koreans -- a $6 million budget and offices in Washington and Kazakhstan.

    It is part of a private graduate school, the Monterey Institute of International Studies.

    By producing information and analysis about nuclear, biological, chemical and other unconventional weapons and training a new generation of arms control specialists, the center has become the largest nongovernmental organization dedicated to fighting the spread of weapons of mass destruction, a hub of arms control expertise, and a magnet to those committed to nonproliferation, which focuses on stopping the spread of weapons of mass destruction.

    Monterey's exquisite location out of the Boston-New York-Washington corridor amuses some of its fans.

    "There's something a little odd at times about having so many bioweaponeers, who tend to be type-A personalities, in laid-back, New Age Monterey, where most people are either retired or massage therapists," said Jonathan B. Tucker, a leading germ warfare expert on leave from the center.

    The center occupies part of the historic two-and three-story adobe buildings of the Monterey Institute. A third of the center's budget comes from foundations and another third from government contracts and grants, including a $9 million, multiyear grant from the Pentagon. The rest comes from sales of publications and subscriptions to the center's databases.

    "The center must be commended for doing the nitty-gritty, nonglamorous reference work upon which so much analysis depends," said Philip Zelikow, a former White House official who directs the Miller Center of Public Affairs at the University of Virginia. "These patiently accumulated databases are probably the best source of information outside of classified government sources about developments that affect nonproliferation."

    The databases benefit from having veritable slave labor to help build them -- the center's graduate students who cull information from sources available to the public in 22 languages. The students, in turn, Dr. Potter says, benefit from learning the computer skills and technology upon which so much modern political science research depends.

    Working on the databases is only one dimension of the center's training. To earn a certificate in nonproliferation as part of their masters' degree, students take 15 units of specialized lecture and seminar courses and participate in a 15-week simulation in which they assume the roles of arms control negotiators.

    Last year, for instance, Dr. Potter and other staff members simulated the talks surrounding the third planned treaty between Moscow and Washington to limit strategic nuclear arms, known as START III. At that session, the role of the representative of the United States's National Security Council was played by one of two young Chinese Foreign Ministry officials sent to Monterey each semester by Beijing.

    His Russian counterpart was played by a young Russian scientist from Snezhinsk, one of Russia's two nuclear weapons laboratories.

    "They negotiated intensively," Dr. Potter said, "and the Russian often tested the patience of his Chinese counterpart by using actual arguments that the Chinese government had used in criticizing America's missile defense policy. But this time, the Chinese diplomat, who was playing an American, had to respond as an American official.

    "They had very tense and testy negotiations -- despite their camaraderie as students. But in this case, they negotiated a treaty that reduced not only strategic, but tactical, or short-range nuclear weapons."

    Tactical weapons are yet to be addressed by the real Russian and American negotiators, who are to begin their talks when the START II treaty is ratified.

    Next semester, Dr. Potter will simulate the conference at the United Nations to review the 1970 Nuclear Nonproliferation Treaty, which bans the acquisition of nuclear weapons by non-nuclear states and provides for inspections of nuclear facilities. Several of the students will attend the conference this spring.

    The leap from theoretical to actual negotiations, a unique aspect of the training, is one of the center's hallmarks. Dozens of its graduates have gone on to jobs in their respective countries arms control groups and agencies. Dr. Tucker and several other faculty members have been United Nations weapons inspectors in Iraq. Amy Sands, the center's deputy director, is a former assistant director of the now-defunct Arms Control and Disarmament Agency.

    Vladimir A. Orlov, a Russian scholar who was one of Dr. Potter's original trainees, was so impressed with center that he founded his own institute in Moscow, the Center for Policy Studies, which now collaborates with Dr. Potter's center on several projects.

    "Bill's work and approach inspired mine," said Dr. Orlov, who returned to Monterey in December for a conference assessing the Clinton administration's efforts to stop the spread of unconventional weapons. "Hopefully, together, we will build a community of people from all of our countries dedicated to stopping the spread of these weapons."

    U.S. Reportedly Hid Nuclear Weapons on 2 Japanese Isles
    By Walter Pincus
    Washington Post
    December 12, 1999

    In the 1950s, the United States secretly maintained nuclear weapons on two Japanese islands occupied by American military forces as a result of agreements ending World War II, according to an article in Monday's Bulletin of the Atomic Scientists.

    More than 500 miles away from the Japanese mainland, the islands of Chichi Jima and Iwo Jima were used to store American nuclear bombs and missiles for U.S. submarines and bombers in the event of a nuclear war, the article says.

    Although the storage of these weapons on American-occupied islands meant the United States technically abided by Japan's non-nuclear principles, "the non-nuclear status of the country was fundamentally undermined," according to William Arkin, one of the authors.

    The new disclosures came as a result of further research by the authors, who in an earlier article mistakenly identified Iceland as the "I" country listed among 15 foreign sites in a declassified Pentagon report that identified where U.S. nuclear weapons were stored during the Cold War.

    "That 'I' country turned out to be Iwo Jima," said Robert S. Norris, another of the authors. Chichi Jima was the "C" country that they had earlier not been able to identify, he added.

    When U.S. military occupation ended in 1951, the two islands stayed under American control with nuclear weapons remaining until the mid-1960s. The weapons were withdrawn from Iwo Jima in 1959 and Chichi Jima in 1965, according to the article. However, when the islands were returned to Japan, a secret 1968 agreement was in effect that granted the United States the right to store weapons there in a military emergency, according to the authors.

    Norris said yesterday he expects the article to be "big news in Japan and raise questions about who in the Japanese government knew and agreed to these programs."

    Because the Japanese people have been the only ones to experience the impact of nuclear weapons, the governments there have kept up the facade that no weapons would ever be produced, possessed or introduced on their territory.

    Over the years, however, there have been public protests about U.S. Navy ships that carry nuclear weapons making port calls and regular stories about American weapons being stored on Okinawa, another U.S.-occupied, Japanese-owned island.

    During this period, and continuing today, the U.S. government policy has been neither to confirm nor deny the presence of nuclear weapons at any site. Throughout the Cold War, Japanese leaders, starting with Prime Minister Nobusuke Kishi, maintained that their country would neither develop nuclear weapons nor permit them on its territory.

    Global Nuclear Stockpiles, 1945-1996
    Quantities for the five declared nuclear powers, year by year.
    posted online 7.9.97

    We are often asked: "How many nuclear weapons are there in the world today?" Or we are asked, "How many were there during the Cuban Missile Crisis?" or at some other point in the Cold War. The truest answer is that probably no one knows for sure.

    American officials know the quantities for the U.S., year by year, and Russian officials know the same about their own stockpile. But, as far as we know, no one in either country has precise details about reserves in the other. The situation is the same for British, French, and Chinese stockpiles, to say nothing of Israeli, Indian, and Pakistani supplies.

    But pleading ignorance won't do, so here is a chart with NRDC's best estimate of the annual totals for the five declared powers from 1945 through 1996.

    End Year    US      SU      UK      FR     CH      Total
    1945         6       -       -       -      -          6
    1946        11       -       -       -      -         11
    1947        32       -       -       -      -         32
    1948       110       -       -       -      -        110
    1949       235       1       -       -      -        236
    1950       369       5       -       -      -        374
    1951       640      25       -       -      -        665
    1952     1,005      50       -       -      -      1,055
    1953     1,436     120       1       -      -      1,557
    1954     2,063     150       5       -      -      2,218
    1955     3,057     200      10       -      -      3,267
    1956     4,618     426      15       -      -      5,059
    1957     6,444     660      20       -      -      7,124
    1958     9,822     869      22       -      -     10,713
    1959    15,468   1,060      25       -      -     16,553
    1960    20,434   1,605      30       -      -     22,069
    1961    24,173   2,471      50       -      -     26,694
    1962    27,609   3,322     205       -      -     31,136
    1963    29,808   4,238     280       -      -     34,326
    1964    31,308   5,221     310       4      1     36,844
    1965    32,135   6,129     310      32      5     38,611
    1966    32,193   7,089     270      36     20     39,608
    1967    31,411   8,339     270      36     25     40,081
    1968    29,452   9,399     280      36     35     39,202
    1969    27,463  10,538     308      36     50     38,395
    1970    26,492  11,643     280      36     75     38,526
    1971    26,602  13,092     220      45    100     40,059
    1972    27,474  14,478     220      70    130     42,372
    1973    28,449  15,915     275     116    150     44,905
    1974    28,298  17,385     325     145    170     46,323
    1975    27,235  19,443     350     188    185     47,401
    1976    26,199  21,205     350     212    190     48,156
    1977    25,342  23,044     350     228    200     49,164
    1978    24,424  25,393     350     235    220     50,622
    1979    24,141  27,935     350     235    235     52,896
    1980    23,916  30,062     350     250    280     54,858
    1981    23,191  32,049     350     275    330     56,195
    1982    23,091  33,952     335     275    360     58,013
    1983    23,341  35,804     320     280    380     60,125
    1984    23,621  37,431     270     280    415     62,017
    1985    23,510  39,197     300     360    425     63,792
    1986*   23,410  45,000     300     355    425     69,490
    1987*   23,472  43,000     300     420    415     67,607
    1988*   23,236  41,000     300     415    430     65,381
    1989*   22,827  39,000     300     415    435     62,977
    1990*   21,781  37,000     300     505    435     60,021
    1991*   20,121  35,000     300     540    435     56,396
    1992*   18,340  33,000     200     540    435     52,515
    1993*   16,831  31,000     200     525    435     48,991
    1994*   15,456  29,000     250     485    435     45,626
    1995*   14,111  27,000     300     485    425     42,321
    1996*   12,937  25,000     260     450    400     39,047
    US = United States, SU = Soviet Union/Russia, UK = United Kingdom,
    FR = France and CH = China

    *The figures for the United States (from 1988) and Soviet Union/Russia (from 1986) include warheads with active, operational forces and retired, non-deployed warheads awaiting dismantlement and weapons in reserve. For recent years the estimate for the former SU/Russia is 50 percent active, 50 percent retired/reserve.

    Panel Urges U.S. to Plan Atomic Weapons Plant, New Warheads
    By Walter Pincus
    Washington Post
    December 10, 1999

    A blue-ribbon scientific panel, appointed by Congress to review the U.S. nuclear stockpile, has recommended that the Department of Energy design a new, billion-dollar plutonium weapons plant and organize teams at the nation's nuclear laboratories to design new warheads for the first time in more than a decade.

    The panel, chaired by John S. Foster, former head of Lawrence Livermore National Laboratory and a senior Defense Department official from 1965 to 1973, said "a paramount concern" is the uncertain future reliability of the already 20-year-old plutonium "pits" at the heart of America's nuclear warheads, according to a declassified version of its report obtained by The Washington Post.

    The report urges the Energy Department to start immediately on the "conceptual design" for a plant to replace the former plutonium facility at Rocky Flats, Colo., which closed in 1989. The panel warned that it could take up to 15 years to put such a plant into operation, mainly because of "political and environmental issues" rather than technical ones.

    The findings of the panel, which included former defense secretary James R. Schlesinger and Harold M. Agnew, former head of Los Alamos National Laboratory, are likely to be welcomed by members of Congress who fear a decline in the U.S. nuclear deterrent and recently voted to reject the Comprehensive Test Ban Treaty.

    The Foster panel's recommendations for more spending on the U.S. nuclear program are echoed in proposals, to be released today, from an internal review of the Energy Department's "stockpile stewardship" program, which seeks to ensure the reliability of American warheads. The review concluded that costs will rise because some of the reductions in nuclear weapons expected from U.S.-Soviet arms control treaties have not materialized.

    It noted, for example, that the Energy Department has not been planning to refurbish older warheads for the Minuteman III land-based intercontinental ballistic missile because those weapons were to be retired with the ratification of the START II.

    But the Russian parliament still has not ratified START II, and the Russian government has warned that the U.S. rejection of the Comprehensive Test Ban Treaty, along with America's efforts to amend the landmark 1972 Anti-Ballistic Missile treaty, could spark a new arms race.

    In sum, "arms control issues may force Energy to keep [old warheads] in the stockpile," the review said.

    U.S. Once Deployed 12,000 Atom Arms in 2 Dozen Nations
    By Judith Miller
    New York Times
    October 20, 1999

    The United States stored 12,000 nuclear weapons and components in at least 23 countries and 5 American territories during the cold war, according to an article based on a recently declassified document. The sites included Morocco, Japan, Iceland, Puerto Rico and Cuba.

    The document, a secret history by the Defense Department covering nuclear deployment from 1945 to 1977, is described in the latest issue of The Bulletin of the Atomic Scientists. Altogether, the report says, the United States stored 38 types of nuclear weapons systems at American or allied bases abroad.

    While other declassified documents have made clear that the United States deployed nuclear weapons and materials overseas, the document confirms how widespread the deployments were, and highlights America's overriding dependence at the time on a worldwide network of weapons of mass destruction.

    The magazine article emphasizes the extent to which the Pentagon made special weapons in which plutonium or uranium could be removed and stored elsewhere. This was in order to evade the issue of whether nuclear weapons or materials were stored in countries where there was intense antinuclear fervor.

    "The Pentagon document fundamentally revises some aspects of postwar nuclear history," said William M. Arkin, a nuclear weapons analyst and one of the article's three co-authors. It reveals, for instance, that the first American nuclear weapons placed overseas were sent not to Britain, as many historians believed, but to Morocco, the site of several strategic American bases.

    But Arkin and his co-authors concluded that the declassified study and an annex listing the countries where nuclear weapons were placed contains some errors. For instance, the annex does not list Portugal's Azores Islands or Libya, though Arkin says that other declassified documents show that the Strategic Air Command stored nuclear weapons in both places in the 1950's and 1960's.

    The article says that American nuclear weapons or materials were once deployed in such sensitive places as Japan, Iceland, Taiwan and Greenland, a possession of Denmark. All those nations have forsworn nuclear weapons and publicly vowed not to store them on their territory.

    They were also to be kept under tight control of American forces, but the article notes that the initial controls were lax.

    Most diplomats from the countries on the list that are considered sensitive on the subject declined to comment on the article and the document, or on whether their governments were aware of any nuclear deployments.

    But a spokesman at the Icelandic Embassy in Washington said, "There is no reason to suspect that any nuclear weapons had ever been stored in Iceland." Some American officials also questioned whether the United States had deployed nuclear weapons on Icelandic territory.

    How the Pentagon document was declassified is a saga in itself. "It has been a 16-year ordeal," said Arkin, who is co-author of a book he was working on at the time, "Nuclear Battlefield" (1985). He requested the document under the Freedom of Information Act in 1983. The study was partly declassified two years later, but most of its annotated charts and country listings were blacked out.

    Arkin, assisted by the Natural Resources Defense Council, a Washington-based nonprofit group of scientists, lawyers and environmentalists, appealed the deletions to the Pentagon. In 1992 and earlier this year, the Pentagon declassified much of the censored material, including the names of nine places were bombs had been stored. But it has continued to suppress the names of 18 countries on the list.

    Because the list was alphabetical, however, and they could see where the names fell in the listing, Arkin and his co-authors -- Robert S. Norris, of the Natural Resources Defense Council, and William Burr, a senior analyst at the National Security Archives, a Washington-based nonprofit group that collects declassified information -- say they were able to deduce their identities.

    The deployment of nuclear weapons domestically and overseas remains among the most closely held military secrets. Arkin said his research indicated that the United States still keeps such weapons in at least seven places -- Belgium, Greenland, Italy, the Netherlands, Germany, Turkey and Britain.

    Kenneth H. Bacon, the Defense Department spokesman, said the Clinton Administration, following a policy long embraced by its Republican and Democratic predecessors, would neither confirm nor deny the existence of nuclear weapons on foreign soil. But he said at least one of the authors' deductions about the countries in which nuclear weapons were stored was not correct.

    Leslie H. Gelb, the president of the New York-based Council on Foreign Relations, who was the State Department's director of political and military affairs between 1977 and 1979, defended the policy of what he called "don't ask, don't tell" with respect to nuclear weapons deployments.

    "You make a country a target by admitting that you've put nuclear weapons there," said Gelb, who wrote about strategic and foreign affairs for The New York Times after he left the Carter Administration.

    Historians, nuclear weapons experts and former Government officials are divided about the likely impact of the document's declassification. Arkin predicted that the disclosures could ignite intense political controversy in countries that are "allergic" to the presence of nuclear weapons and whose governments have forsworn their storage.

    The document and its annex, coupled with other declassified information obtained by the article's authors, show that during the 1970's, the United States had more than 7,000 nuclear weapons in NATO countries, and more than 2,000 on land in the Pacific region.

    Graham T. Allison, a professor at Harvard University's Kennedy School and a co-author of "Essence of Decision: Explaining the Cuban Missile Crisis," said he had not known until he read the version of the declassified document's annex on the web that the United States had stored depth charges -- with the nuclear materials removed -- at its base in Guantánamo, Cuba.

    The article and the authors' version of the annex are available online, at

    Donald P. Gregg, president and chairman of the Asia Society, who was the American Ambassador to South Korea between 1989 and 1993, confirmed the article's assertion that America had once sent nuclear weapons there. He had raised the issue of their removal with Korean leaders more than a year before President Bush announced in 1991 that he was withdrawing all tactical nuclear weapons sent overseas.

    Gregg said he had concluded, and the American military had agreed, that the weapons did not enhance American national security and could have become a provocation to North Korea.

    "My residence had just been broken into by six students angry about beef quotas," he recalled. "They tried to burn my house down. And I thought, 'God Almighty, if they get this mad about beef, what will they do when they learn we have nuclear weapons here?' "

    Gallup Japan Poll on the Ownership of Nuclear Weapons and the Threat of Nuclear War
    Japanese doubt nuclear war is likely in the next decade
    June 5, 1999

    TOKYO, JAPAN -- A Gallup Japan public opinion poll shows that the Japanese people doubt a nuclear war is likely within the next decade, as well as downplay the chances that Japan might be the target of nuclear attack by some country.

    By contrast, while Americans share the Japanese doubts about the likelihood of a nuclear war in general, they are twice as likely as the Japanese to believe their own country could be the target of a nuclear attack.

    Gallup Japan conducted a poll in July, 1998 on "The Ownership of Nuclear Weapons and the Threat of Nuclear War" through its Tokyo call center.

    This poll, in the interest of comparing differences in awareness between Japan and the U.S., incorporated questions from a poll on nuclear war conducted by The Gallup Organization in the U.S. in early June, 1998.

    Summary of Poll Findings

    According to the poll, 82% of Japanese believe the development of the atomic bomb was a bad thing, compared with 61% of Americans. In both Japan and the U.S., two in three felt there was little chance of a nuclear war breaking out within the next ten years. However, 36% of Americans felt that it was "very likely" or "fairly likely" that the U.S. would be attacked by another country using nuclear weapons, compared with just 16% of Japanese who felt this way about Japan being attacked.

    When asked to evaluate the threat to world peace posed by specific nations that currently either have, or could have, nuclear weapons, both Japanese and Americans believed Iraq and Iran to be leading threats. Japanese also felt that North Korea would also be serious threats, while Americans pointed to Pakistan.

    Nearly 90% of all Japanese said there was no need for Japan to possess the atomic bomb in the future. In other words, almost 10% felt that Japan would need nuclear weapons.

    Regarding the future of the Nuclear Non-Proliferation Treaty, 65% of respondents sought further reductions in nuclear capabilities, noting that "fewer countries should be allowed to have nuclear weapons, and restrictions should be tightened."

    Four in five Japanese believe that the development of the atomic bomb was a bad thing. Two in three Americans feel the same way.

    82% of all Japanese feel that the invention of the atomic bomb was a bad thing.

    While all major societal groups examined in the poll feel the development of the bomb was bad, Japanese men and adults in their twenties and thirties are about twice as likely as women and older Japanese to say that development of the atomic bomb was a good thing.

    On balance, Americans also feel that the development of nuclear weapons was a bad thing, but by a much narrower margin than in Japan. Overall, Americans are more than twice as likely as the Japanese to consider the bomb a good thing (36% vs. 15%).

    Japanese: "Even if a nuclear war were to break out somewhere in the world, Japan would be safe." Americans: "The U.S. might be attacked in the event of a nuclear war."

    When Japanese respondents were asked about the possibility that their own country would "get into a nuclear war within the next 10 years," the largest percentage, 39%, said it was "very unlikely." Taking into account those who felt such a war was "fairly unlikely," a total of 65% believe there is little chance of nuclear war involving Japan within the next ten years.

    When respondents were asked about the possibility of Japan being attacked by another country using nuclear weapons within the next ten years, 83% responded that such a scenario was unlikely.

    Therefore, a majority of Japanese believe that a nuclear war is unlikely to break out in the near future and that, even if it does, Japan would not be attacked.

    Americans had similar opinions regarding the possibility of nuclear war. However, one in five felt it was "very likely" that the U.S. would be attacked with nuclear weapons within the next ten years. When this group was combined with those who felt it was "fairly likely," 36% of Americans felt that such a scenario was likely to happen. In other words, Americans are more likely than Japanese to be worried that their country would be involved if a nuclear war were to break out.

    Among Japanese, women and those in their twenties and thirties were more likely than were respondents in other groups to think that it was likely ("very likely" & "fairly likely") that their country would be attacked with nuclear weapons.

    Japanese believe that the nuclear capabilities of Iraq, Iran and North Korea seriously threaten world peace.

    When asked which of 13 countries* with nuclear capabilities represented threats to world peace, Japanese were most likely to answer Iraq, followed by North Korea, Iran, and Israel.

    In the wake of nuclear tests by India and Pakistan, a slightly higher percentage of Japanese felt threatened by Pakistan than by India. The U.S. was ranked tenth out of the thirteen countries, but 53% of the respondents still felt that it represented a threat to world peace.

    *The 13 countries were drawn from the nine countries included in a poll conducted by The Gallup Organization in June 1998 (Russia, Great Britain, China, India, Pakistan, Israel, Brazil, Iraq, and Iran), countries that have already announced that they possess nuclear weapons (U.S., France, Great Britain, Russia, and China) and countries thought to be currently pursuing nuclear weapons development programs (Iran, Libya, and North Korea - from The 21, April 1996).

    Both Japanese and Americans Feel Threatened by Iraq and Iran

    When the results of the Japanese survey were compared with those of the U.S. poll, Americans tended to group the 13 countries into those considered threats to world peace (such as Iraq, at 89%) and those not considered threats (such as Great Britain, at 13%). Japanese, on the other hand, tended to view all nations with nuclear weapons capabilities as potential threats. Both Japanese and Americans felt that Middle Eastern nations like Iraq and Iran posed threats and that such countries as Brazil and Great Britain did not represent major threats. However, Japanese were considerably more likely than were Americans to view Israel and India as potential threats.

    Nine in Ten Japanese Believe That Japan Does Not Need the Atomic Bomb

    When asked whether Japan needed nuclear weapons capabilities**, 89% of Japanese said "No." Still, 9% felt that Japan does need to have its own nuclear weapons capability.

    **Respondents were instructed to answer for nuclear weapons and not for the fuel used in nuclear reactors.

    Two in Three Japanese Feel That Treaty Guidelines Should Be Strengthened

    When asked whether the Nuclear Non-Proliferation Treaty should be continued, fully 65% of Japanese believed that "fewer countries should be allowed to have nuclear weapons, and restrictions should be tightened." Only 22% felt that the Treaty should be maintained in its present form.

    Survey Methods
    The Gallup Japan Poll

    Area Surveyed: Tokyo metropolitan area
    Sample Frame: Men and women aged 20 and older
    Sample Size/Composition: Designed to provide 500 valid responses (gender and age were matched to demographics for Tokyo metropolitan area)

    By Gender
    Male: 250 (50.0%)
    Female: 250 (50.0%)

    By Age
    20-29: 115 (23.0%)
    30-39: 90 (18.0%)
    40-49: 94 (18.8%)
    50-59: 88 (17.6%)
    60 and older: 113 (22.6%)

    Methodology: Telephone survey conducted at Gallup Japan call center
    Time Frame: July 11-15, 1998

    The Gallup U.S. Poll
    Area Surveyed: United States (nationwide)
    Sample Frame: Men and women aged 18 and older (1,003)
    Time Frame: June 5-7, 1998

    Broken Arrows and Bent Spears:
    The frightening world of nuclear accidents
    By Bruce Kennedy
    CNN Interactive

    The concept itself is terrifying, even hypothetically. A nuclear weapon, lost, stolen or accidentally destroyed -- endangering thousands, perhaps millions of lives.

    "Broken Arrows," as the U.S. military calls such worst-case scenarios, have been plot devices in action movies and spy novels. But the reality, as reflected in today's headlines, sometimes makes such fiction pale in comparison.

    Scores of accidents involving nuclear reactors and weapons have occurred worldwide since the Nuclear Age began in 1945. And an estimated 50 nuclear warheads still lie on the bottom of the world's oceans, according to Joshua Handler, a former research coordinator for the environmental activist organization Greenpeace.

    Officially, the governments of the nuclear powers are not very forthcoming with information regarding nuclear accidents. The United States last published such a list in 1980, which revealed 32 nuclear accidents or incidents, while Russia has divulged few if any details on such incidents.

    But, says Handler, the Russians -- as a people -- have shrugged off decades of official suspicion and secrecy and are now talking about some of the nuclear near-disasters that took place in their armed forces.

    "They can be surprisingly open in details," he says, "either officially or with people publishing their personal recollections in the press."

    Handler, now a researcher at Princeton, co-authored Greenpeace's "Neptune Papers" series, which chronicled naval accidents around the world from 1945 to 1989. And he has continued to document such accidents, especially in the former Soviet Union, using recently published information as well as interviews he conducted with low- and high-ranking Russian naval officers.

    "They're more adjusted to post-Cold War openness than our guys," he says. "On a human level you would have a more detailed discussion on nuclear weapons and naval nuclear issues with a Russian officer than with a U.S. officer."

    The U.S. Department of Defense has standard answers to any questions regarding its nuclear weapons. Regarding storage of nuclear weapons: "It is U.S. policy neither to confirm nor deny the presence or absence of nuclear weapons at any specific location."

    If asked whether nuclear weapons are aboard a specific naval vessel or aircraft, the DOD tells its personnel to respond: "It is general U.S. policy not to deploy nuclear weapons aboard surface ships, attack submarines and naval aircraft. However, we do not discuss the presence or absence of nuclear weapons aboard specific ships, submarines or aircraft."

    All of the U.S. military incidents listed in our interactive map involve the Navy and Air Force. CNN Interactive contacted the Defense Department for comment on the incidents mentioned in this section. Defense officials referred CNN Interactive to the two branches of the service involved.

    The Navy, following repeated requests for comment, issued the following statement by Cmdr. Frank Thorp shortly before publication:

    "It is disingenuous and perhaps misleading to describe these events as 'nuclear incidents.' The list appears to be partially researched, incomplete and alarmist in nature. I have nothing to add to the Department of Defense's narrative summaries of accidents involving U.S. nuclear weapons from 1950-1980."

    The Air Force, in a statement sent to CNN, said it had "no updates to the Department of Defense's narrative summaries of accidents involving U.S. nuclear weapons from 1950-1980."

    The following terms are taken verbatim from U.S. Defense Department Directive 5230.16, "Nuclear Accident and Incident Public Affairs (PA) Guidance," issued December 20, 1993:

    A Chairman of the Joint Chiefs of Staff term to identify and report an accident involving a nuclear weapon or warhead or nuclear component.

    An unexpected event involving nuclear weapons or nuclear components that results in any of the following:
    a.Accidental or unauthorized launching, firing, or use by U.S. forces or U.S supported Allied forces of a nuclear-capable weapons system.
    b.An accidental, unauthorized or unexplained nuclear detonation.
    c.Non-nuclear detonation or burning of a nuclear weapon or nuclear component.
    d.Radioactive contamination.
    e.Jettisoning of a nuclear weapon or nuclear component.
    f.Public hazard, actual or perceived.

    A Chairman of the Joint Chiefs of Staff term used in the Department of Defense to identify and report a nuclear weapon significant incident involving a nuclear weapon or warhead, nuclear components, or vehicle when nuclear loaded.

    A reporting term to identify and report the seizure, theft, or loss of a U.S. nuclear weapon.

    A reporting term to identify an event involving a nuclear reactor or radiological accident.

    Most of the major accidents of the 1950s involved nuclear weapons on board land-based military aircraft. The technology for intercontinental ballistic missiles, as well as submarine-based missiles, was still in its infancy.

    April 11, 1950 -- New Mexico, United States
    A U.S. B-29 departing Kirtland Air Force Base in New Mexico crashed three minutes after takeoff. Detonators had been installed on a nuclear bomb on board, but because the capsule of fissile material had not been inserted, nuclear detonation was not possible. The bomb's casing was destroyed and some high explosive burned in the fire.
    (Source: U.S. Defense Department)

    February 5, 1958 -- Off Georgia, United States
    A B-47 on a simulated combat mission collided with an F-86 near Savannah, Georgia. The B-47 crew made three attempts to land at Hunter Air Force Base with the nuclear weapon on board, but could not land safely because of collision damage. The weapon was jettisoned into water from an altitude of 7,200 feet. It landed safely, but subsequent searches failed to locate the weapon. A nuclear detonation was not possible since the nuclear capsule was not on board the aircraft.
    (Source: U.S. Defense Department)

    November 10, 1950 -- Quebec, Canada
    The U.S. Defense Department, in its 1980 publication on nuclear accidents, stated the following: "A B-50, experiencing an in-flight emergency, jettisoned a bomb over water (outside the United States) from an altitude of 10,500 feet. The weapon's HE [high explosive] detonated on impact." The report failed to mention that the accident apparently took place just north of the U.S. border in Quebec. According to John Clearwater, a Canadian Defense Department employee working independently on a study of nuclear weapons in Canada, the B-50 jettisoned a Mark 4 bomb over the St. Lawrence River near Riviere-du-Loup, about 300 miles northeast of Montreal. Clearwater told The Canadian Press that the weapon, lacking its essential plutonium core, was detonated above the river. According to Clearwater, detonation of the bomb's high explosives shook the region, scattering nearly 100 pounds (45 kg) of uranium. The U.S. Air Force reportedly covered up the incident at the time, saying a load of conventional practice bombs had been jettisoned by the B-50, which later landed safely at a U.S. Air Force base in Maine.
    (Sources: U.S. Defense Department; The Canadian Press)

    March 10, 1956 -- Exact Location Unknown
    A B-47 carrying two nuclear capsules in carrying cases on a nonstop deployment from MacDill Air Force Base in Tampa, Florida, to an overseas air base failed to contact its tanker over the Mediterranean Sea for a second refueling. After an extensive search, no trace was found of the B-47.
    (Source: U.S. Defense Department)

    February 28, 1958 -- Great Britain
    A B-47 bomber, reportedly loaded with a nuclear weapon, caught fire at the U.S. air base at Greenham Common, England, and completely burned. In 1960 a group of scientists working at the Atomic Weapons Research Establishment (AWRE) at Aldermaston found signs of high-level radioactive contamination around the base. The U.S. government has never confirmed whether the accident at Greenham Common involved a nuclear warhead
    (Source: Campaign for Nuclear Disarmament)

    July 27, 1956 -- Great Britain
    A B-47 bomber with no weapons on board crashed into a nuclear weapons storage facility at the Lakenheath Air Base in Suffolk, England, during a training exercise. In a previously secret cable, Gen. James Walsh, commanding officer of the U.S. 7th Air Division in Britain, said the aircraft demolished a concrete weapons store, known as an "igloo," containing three Mark 6 bombs -- similar to the weapon that destroyed Nagasaki, Japan. "The B-47 tore apart the igloo and knocked about three Mark Sixes," Walsh said in his terse cable to Gen. Curtis LeMay, commander of the U.S. Strategic Air Command. "Aircraft then exploded, showering burning fuel over all. Crew perished. ... Preliminary exam by bomb disposal officer says a miracle that one Mark Six with exposed detonators sheared didn't go." A Defense Department description of the accident said "no capsules of nuclear materials were in the weapons or ... the building."
    (Sources: U.S. Defense Department; National Security Archive)

    The introduction of missile-launching submarines added a new dimension to the nuclear threat, as Soviet and U.S. subs stalked each other. The underwater cat-and-mouse game sometimes ended with lethal results. Major accidents also occurred on board vessels with nuclear reactors.

    April 11, 1968 -- Pacific Ocean
    A Soviet diesel-powered "Golf"-class ballistic missile submarine sank about 750 miles northwest of the island of Oahu, Hawaii, in about 16,000 feet of water. All 80 people on board the vessel were killed. In March 1975, several newspapers published stories about the CIA's attempt to raise the submarine in 1974 using the specially constructed "Glomar Explorer" deep-water salvage ship. Part of the submarine was reportedly raised. Reports say the submarine was carrying three nuclear-armed ballistic missiles, as well as several nuclear torpedoes.
    (Sources: Greenpeace; Joshua Handler, Princeton University)

    January 21, 1968 -- Thule, Greenland
    A B-52 carrying four nuclear weapons crashed and burned near Thule Air Base in Greenland. All the weapons were destroyed and some radioactive contamination occurred at the crash site, which was on sea ice. Some 237,000 cubic feet of contaminated ice, snow and water, along with crash debris, were removed to an approved storage site in the United States. Representatives of the Danish government monitored the cleanup operations.
    (Source: U.S. Defense Department)

    January 24, 1961 -- North Carolina, United States
    A B-52 on airborne alert experienced structural failure of its right wing, resulting in the release of two nuclear weapons. The parachute on one weapon deployed and allowed it to land with little damage. The second fell free and broke apart near the town of Goldsboro, North Carolina. Though no explosion occurred, some of the uranium from that weapon could not be recovered because it had been buried too deep to locate. No radiological contamination was detectable in the area.
    (Sources: U.S. Defense Department; Goldsboro News-Argus)

    April 10, 1963 -- Atlantic Ocean
    The U.S. nuclear-powered submarine Thresher imploded and sank in approximately 8,500 feet of water 100 miles east of Cape Cod, Massachusetts. All 129 on board were killed. The vessel was never recovered.
    (Source: Greenpeace)

    May 1968 -- Atlantic Ocean
    Details of this accident remain classified by the U.S. Defense Department. But media reports say it involved the U.S. submarine Scorpion, which sank 400 miles southwest of the Azores in 10,000 feet of water. All 99 crewmen on board were killed. The ship was reportedly carrying several nuclear ASTORs, or anti-submarine torpedoes.
    (Sources: Greenpeace; Chicago Tribune, January 6, 1991)

    January 17, 1966 -- Palomares, Spain
    A B-52 carrying four nuclear weapons collided with a KC-135 during refueling operations and crashed near Palomares, Spain. One weapon was recovered on the ground and another from the sea after extensive search and recovery efforts. The two other weapons hit the ground, resulting in the detonation of their high explosives and the subsequent release of radioactive materials. Approximately 1,400 tons of contaminated soil and vegetation were removed to the United States for storage at an approved site. Representatives of the Spanish government monitored the cleanup operations.
    (Source: U.S. Defense Department)

    July 4, 1961 -- North Sea
    A major accident occurred on the K-19 "Hotel"-class Soviet nuclear-powered ballistic missile submarine off Norway. A cooling system failed, contaminating crew members, missiles and some parts of the ship with radiation. Temperatures inside one of the sub's two reactors soared to 800 degrees Celsius and threatened to melt down the reactor's fuel rods. Emergency measures by the crew, however, brought down the reactor's core temperature. Several fatalities were reported. Details of the accident emerged in 1990 at a conference in Luxembourg on nuclear accidents, according to a Reuters report.
    (Source: Joshua Handler, Princeton University)

    November 1969 -- White Sea
    In 1975, The New York Times reported that the U.S. nuclear-powered submarine Gato collided with a Soviet submarine on November 14 or 15, 1969, near the entrance of the White Sea. The Times quoted a crew member, who said the Gato was struck in the heavy plating that serves as a protective shield around its nuclear reactor. The ship sustained no serious damage, but the Gato's weapons officer prepared for orders to arm a nuclear-tipped anti-submarine warfare missile and three nuclear-armed torpedoes.
    (Sources: Joshua Handler, Princeton University; The New York Times, July 6, 1975)

    Mid-1960s (date undetermined) -- Kara Sea
    An accident took place on board the Soviet nuclear-powered icebreaker Lenin that led to the dumping of its reactors in the Kara Sea, a body of water that connects to the Arctic Ocean. Some accounts said the Lenin experienced a reactor meltdown.
    (Sources: Greenpeace; Joshua Handler, Princeton University; Rachel's Hazardous Waste News)

    December 5, 1965 -- Pacific Ocean
    An A-4E Skyhawk attack aircraft loaded with one B43 nuclear weapon rolled off the deck of the USS Ticonderoga while the aircraft carrier was traveling from operations off Vietnam to Yokosuka, Japan. The plane and its pilot sank in 16,200 feet of water. Pilot, plane and weapon were never found. The U.S. Defense Department reported the incident took place "more than 500 miles from land." But Greenpeace, quoting U.S. Navy documents, said the accident occurred about 80 miles east of the Japanese Ryuku Island chain and about 200 miles east of Okinawa.
    (Sources: Greenpeace; U.S. Defense Department)

    Both Washington and Moscow sent to sea larger armadas of submarines to add to their nuclear deterrents. The bigger submarine fleets also meant more accidents. Poor weather played a role in another naval near-disaster.

    April 12, 1970 -- Atlantic Ocean
    A Soviet "November"-class nuclear-powered attack submarine experienced an apparent nuclear propulsion problem in the Atlantic Ocean about 300 miles northwest of Spain. The submarine apparently sank after failing to connect a tow line to a Soviet bloc merchant ship; 52 people were killed.
    (Source: Greenpeace, United Press International)

    November 22, 1975 -- Off Sicily, Italy
    The aircraft carrier USS John F. Kennedy and the cruiser USS Belknap collided in rough seas at night during exercises about 70 miles east of Sicily, setting off fires and explosions. The commander of Carrier Striking Forces for the U.S. Sixth Fleet, reporting to his commanders soon after the accident, declared a possible nuclear weapons accident. No subsequent nuclear contamination was discovered during the fire and rescue operations.
    (Source: Greenpeace)

    November 22, 1975 -- Pacific Ocean
    The newspaper Vladivostok in 1993 reported that the K-171, a Soviet nuclear-powered ballistic missile submarine, accidentally jettisoned a nuclear warhead off the Soviet coast near Kamchatka in 1977. After a frenzied search by dozens of Soviet naval vessels and aircraft, the warhead was located and recovered.
    (Source: Joshua Handler, Princeton University)

    June 20, 1970 -- Pacific Ocean
    According to a 1991 Chicago Tribune report, a Soviet "Echo"-class nuclear-powered submarine collided with the U.S. nuclear-powered submarine Tautog in the northern Pacific. The Tautog had been secretly following the Soviet sub for several hours when the Soviet vessel made a 180-degree turn and, according to the article, unexpectedly accelerated towards the Tautog. Crew members interviewed for the article said they thought the Soviet submarine sank after the collision. But Russian Navy officers, interviewed in 1992, say the Soviet submarine did not sink.
    (Sources: Joshua Handler, Princeton University; Chicago Tribune, January 6, 1991)

    Human and mechanical errors led to a series of highly publicized accidents. But a new sprit of U.S.-Soviet cooperation toward the end of the decade assured both sides that that accidents were not provocative.

    September 19, 1980 -- Arkansas, United States
    In Damascus, Arkansas, during routine maintenance in a missile silo, a technician caused an accidental leak in a Titan II missile's pressurized fuel tank. Nearly nine hours after the initial leak, fuel vapors within the silo exploded. The pair of doors covering the silo, each weighing 740 tons, were blown off by the blast, and the nine megaton warhead was hurled 600 feet away. The warhead was recovered intact. One technician was killed in the explosion.
    (Sources: U.S. Defense Department; Arkansas Democrat-Gazette, September 20, 1981; Stephen Schwartz, letter to the editor, Commentary magazine, January 1997)

    October 3, 1986 - Atlantic Ocean
    A Soviet "Yankee I"-class nuclear-powered ballistic missile submarine suffered an explosion and fire in one of its missile tubes 480 miles east of Bermuda. At least three crew members were killed. Gorbachev sent Reagan a private communication regarding the accident in advance of a public announcement on October 4. Gorbachev assured Reagan there was no danger of nuclear explosion, radioactive contamination or accidental launching of nuclear missiles. The submarine sank while under tow on October 6 in 18,000 feet of water. Two nuclear reactors and approximately 34 nuclear weapons were on board.
    (Sources: Greenpeace; Facts on File; Joshua Handler, Princeton University)

    April 7, 1989 - Atlantic Ocean
    The Komsomolets, a Soviet nuclear-powered attack submarine, caught fire and sank about 300 miles north of the Norwegian coast. Forty-two of the 69 crew members were killed. Also lost were the vessel's single nuclear reactor and two nuclear-armed torpedoes.
    (Sources: The Associated Press, United Press International)

    August 10, 1985 - Near Vladivostok, Russia
    An "Echo"-class Soviet nuclear-powered submarine suffered a reactor explosion at the Chazhma Bay repair facility, about 35 miles from Vladivostok. Soviet news accounts say radiation monitors in the area recorded fatally high levels of radiation. Ten officers were killed in the explosion. A cloud of radioactivity spread from the accident site toward Vladivostok but did not reach the city.
    (Source: Joshua Handler, Princeton University)

    The collapse of the Soviet Union drained the former Soviet republics of funds for their armed forces. A lack of routine maintenance put many vessels out of commission or led to accidents on those still working. Despite the apparent end of the Cold War, U.S. and Russian submarines continued to shadow each other -- occasionally with dangerous results.

    September 27, 1991 -- White Sea
    A "Typhoon"-class nuclear-powered ballistic missile submarine suffered a missile launch malfunction during a test launch in the White Sea near Severodvinsk. The Tass news agency, in a report issued several weeks after the incident, said a defect was discovered while the submarine was still under water. After surfacing, the missile reportedly began burning and spontaneously left its launch tube. A fireball was reported on deck. To put the fire out, the vessel dived.
    (Source: Joshua Handler, Princeton University)

    February 11, 1992 -- Barents Sea
    A CIS (Commonwealth of Independent States) "Sierra"-class nuclear-powered attack submarine collided with the U.S. nuclear-powered attack submarine Baton Rouge in the Barents Sea. Western news reports quoted the U.S. Navy as saying the Baton Rouge was at periscope depth when it was hit by the surfacing CIS submarine. There was no apparent damage, and the Baton Rouge returned to its home port in Norfolk, Virginia. The Interfax news agency quoted chiefs of the former Soviet Navy, who said the incident took place inside Russian territorial waters. Those officials also rejected the U.S. Navy's version of the incident -- that the U.S. submarine was outside Russian territorial waters.
    (Source: Joshua Handler, Princeton University)

    March 20, 1993 -- Barents Sea
    The U.S. nuclear-powered submarine Grayling collided with a Russian Delta III nuclear-powered ballistic missile submarine in the Barents Sea some 105 nautical miles north of the Kola Peninsula. A Russian naval spokesman said the submarine returned to its base. Both vessels reportedly suffered only minor damage.
    (Source: Facts on File, The Associated Press)