May/June 2000
Vol. 56, No. 3, pp. 14-17

by Diego Lluma

"I couldn't put my trousers on. My leg started to hurt. My hands started to burn, although at first they looked normal. I put my hands in water all day and all night and started to peel the skin off my fingers. For five or six months I couldn't get out of bed. As soon as I did, I would start bleeding."

This testimony is typical of 11 Georgian soldiers who, in February 1997, started developing what seemed to be radiation burns. But the military doctors who treated the soldiers couldn't figure out how they had been injured. The base where they were stationed, the Lilo Training Detachment of Frontier Troops located just outside the capital, Tbilisi, had no record of ever having housed nuclear materials.

Then, on August 26, several months after the soldiers first reported the mysterious burns, a radiological team from the Georgian Army detected high levels of radiation near an underground shelter at the base. Their suspicions aroused, Georgian authorities asked Russian specialists from the Institute of Physics in Moscow to evaluate the soldiers. The specialists diagnosed their injuries as radiation burns that had apparently resulted from repeated exposures over the course of several months.

Photo by Diego Lluma
Abel Gonzalez, director of Nuclear Safety and Waste at the International Atomic Energy Agency, and an expert on orphaned radioactive sources.

But how could soldiers at a non-nuclear site receive radiation burns? What was the source of the radiation? And how did it get on the base? Local authorities had no answers.

Orphans

Georgian investigators would soon discover that the Lilo base was littered with so-called "orphan sources"--radioactive source materials that were lost, stolen, or abandoned. Usually, orphan sources turn out to be commercial materials, most often abandoned medical supplies or radioactive metals that have been blended with scrap for recycling.

The Lilo case, however, added a new twist to the problem. According to Abel Gonzalez, director of Nuclear Safety and Waste at the International Atomic Energy Agency (IAEA), the sources discovered at Lilo had been used by the Soviet military for nuclear war training. What is remarkable about this case, he says, is that when Russian troops abandoned the base in 1992 they left behind scores of radioactive sources and failed to tell anyone about them. The unsuspecting Georgians subsequently turned the base into a training camp for border troops.

During an interview in his office in Vienna last October, Gonzalez told me the story of the Lilo base and how the situation there--together with similar discoveries in other parts of Georgia--had become a central concern in the IAEA's efforts to contain the problem of orphan sources.

Photo by Diego Lluma
Storage containers for the radioactive sources found at Georgia's Lilo army base.

Lilo

After the first radiation measurements were taken on August 26, 1997, Georgian President Edouard Shevardnadze ordered a national working group of specialists to investigate.

On September 13, two days after the investigation began, the source of the radiation was discovered in the pocket of a winter jacket that the soldiers had been sharing for guard duty. It was a small cesium 137 metal cylinder that had a dose rate of about 45 millisieverts per hour at a distance of one meter. (Worldwide average background radiation is 2.7 to 3.4 millisieverts per year.)

Further measurements showed there was no additional contamination in the immediate area, but a slight increase in background level was detected nearby, which led to finding another source buried 20 centimeters beneath a soccer field. A higher rate was also measured just a few meters from the smoking area, which led to the discovery of still more sources.

At this stage the working group decided to survey the whole facility. After monitoring the entire base--about 250,000 square meters--investigators found eight other sources of varying activity levels.

Two other cesium 137 sources were eventually found, but they were stored in lead containers and thus emitted little radiation. The investigation extended to four other locations just outside the base where the working group found 200 discarded night-vision devices for machine guns, which contained radium 226.

On October 9, the Georgian Minister of Health asked the IAEA to help treat the soldiers and to send an emergency team to evaluate the radiological situation at the base.

Although Georgia was not a member state of the IAEA, nor a signatory of the "Convention of Assistance in the Case of a Nuclear Accident," the IAEA agreed to help. According to Gonzalez, the agency considered the case a "major risk."

The first IAEA team arrived in Lilo on October 11. It assisted in the recovery of sources and performed a radiological survey of the accident site. It also verified that the radioactive sources discovered up to that point--including 12 cesium 137 sources and a number of radium 226 sources--were placed in lead containers and safely stored.

According to Gonzalez, the buried devices were used "to train troops on how to move in a contaminated battlefield." By holding maneuvers on contaminated ground, soldiers could learn how to calibrate equipment used for radiological monitoring during nuclear accidents or a nuclear war.

The problem grows

After the Georgian working group completed its investigation at the base, President Shevardnadze set up a national commission to inspect Georgia's other military bases. By November 1997, the commission had identified 352 contaminated sites.

In one case, the commission discovered dozens of cesium 137 sources at a former Soviet missile base in Vaziani. Seven of the sources were found in a facility designed to store spent nuclear fuel. These devices had apparently been found somewhere else in 1993 and then transported to the facility for storage.

In July 1998, several more discoveries were made: three abandoned sources were found in Matkhoji, a village 300 kilometers west of Tbilisi; portions of a former Soviet military base near Kuthaisi were found to be contaminated with radium 226; and two radioactive sources were found at a military base in the city of Poti, close to the Black Sea.

The worst, however, was yet to come.

In October 1998, two extremely potent sources were discovered near the village of Khaishi, in western Georgia.

According to Carlos Nogueira de Oliveira, coordinator of the IAEA's Center for Emergency Response--a unit created after the Chernobyl accident to aid countries during a nuclear crisis--the discovery at Khaishi was "the most serious thing that happened in Georgia." These were power sources--one of which was not enclosed in shielding--and they were originally taken to Khaishi during the construction of a hydroelectric plant on the Inguri river. "They were brought from the Soviet Union," Nogueira explains, "to power communication devices for establishing radio communication from remote areas." The devices use heat from radioactive decay to produce power.

One source was found on the bank of the Inguri, 80 meters down in a canyon. It was found by accident when the water level was low, allowing a fisherman to find a "piece of metal." When he approached it, he felt heat coming from the cylinder and decided not to touch it. "If he had, he might have received an awful burn, as the source had a temperature of 400 degrees [Celsius]," says Nogueira.

Instead, the fisherman contacted the Civil Defense Service. A recovery operation was carried out by the Institute of Physics and the Ministry of the Environment of Georgia.

The source was made of strontium 90 and had an activity of about 40 kilocuries. The dose rates measured 90 millisieverts per hour at the surface of the container, and 2.9 millisieverts per hour at a distance of one meter.

An even more powerful source was subsequently found nearby. It was made of solid ceramic strontium and had a dose rate of 50 millisieverts per hour at a distance of two meters.

According to Oliveira, more of these sources are still hidden somewhere in Georgia. "We have only recovered four, the last two in May 1999. There are four more missing somewhere."

To give an idea of the magnitude of the dangers these devices present, Gonzalez compares the situation in Georgia to a 1987 accident in Goiania, Brazil. In that case, a radiation therapy unit was left behind in an abandoned clinic. Scavengers broke open the protective casing that housed the machine's cesium 137 and sold the glowing salt-like substance to curious buyers. In the end, more than four hundred people were contaminated and four people died. The cesium had an activity level of about 1,000 curies.

"The devices we found in Georgia," says Gonzalez, "emitted about 40,000 curies, and we know that the Soviets produced sources with up to 150,000 curies." The Russian ambassador to the IAEA told Gonzalez that the Soviet Union manufactured 1,000 of these sources, of which more than 100 are outside Russia. The devices, which Gonzalez believes were used by the Soviet military, have not been accounted for--and nobody, apparently, knows where to start looking.

"These devices were built in the Stalinist way," remarks Gonzalez. "They used a very simple principle: you put a whole lot of activity inside, then you put shielding around it. The container gets hot and you use that heat as a thermocouple. Obviously the design of a device should take safety into consideration, but in the 1950s the idea was to win the war against the Americans without paying attention to anything else."

Where next?

Near the door of the IAEA's Center for Emergency Response in Vienna, a blackboard reads "Current events: Georgia"--meaning the problem is only partially under control.

No one knows for certain what crises are waiting to happen in the other former republics. But the question was one of the principal topics of the 1998 International Conference on the Safety of Radiation Sources and the Security of Radioactive Materials, held in Dijon, France, and co-sponsored by the IAEA, the European Commission, the World Customs Organization, and Interpol.

At this point we only know what's going on in Georgia, we know nothing about what's happening in other countries of the former Soviet Union," says Nogueira cautiously.

Gonzalez is more direct: "There are lots of these sources. So many I can't quantify them. Nobody knows what's going on in the former Soviet Union. But the Russians tell me that they think the situation is disastrous."

Hazardous material

According to Gonzalez, although the radioactive materials lost in Georgia can't be used to make nuclear explosives, they can do a lot of harm to those who handle them.

The injuries sustained by the 11 soldiers attest to this. The burns were so severe that the Georgian government looked abroad for help in caring for the soldiers. Four were sent to the Curie Institute and the Percy Hospital in Paris. The other seven received treatment at the dermatology department of the University of Ulm and the Armed Services Hospital in Germany. The four with the most severe burns received further treatment at the Radiological Research Center of the Russian Academy of Medical Science in Obninsk.

The physical form of the devices found in Georgia poses risks as well, says Gonzalez. Because they are metallic--and not chalk-like as was the cesium in the Brazilian case--the IAEA is concerned that similar devices will go undetected and eventually end up being mixed with scrap metal for recycling. If melted, they could create a radioactive cloud that might spread for miles.

That is exactly what happened in 1998 when above-normal radiation levels were detected in Switzerland. "Russia again," thought Gonzalez when he first heard the report. But the origin of that radioactive cloud turned out to be Cadiz, Spain.

"Nobody knows where that source came from exactly. It's very difficult to say and there are different opinions about its potency," says Nogueira.

What is known is that contamination from scrap melted by the Spanish company Acerinox crossed Spain, France, Italy, and Germany before being detected in Switzerland.

Since the accident in Chernobyl in 1986, most European countries have established permanent field radiation detectors to monitor the environment. After the Cadiz incident, the Spanish government demanded that every company dealing with scrap use special devices to monitor for radioactivity.

Meanwhile, more sources have been found in Georgia. Last June, a cobalt 60 source was found near the botanical gardens in Tbilisi and in July two more cesium 137 sources were found in the town of Rustavi.

Gonzalez calls the orphan sources discovered in Georgia one more "legacy of the Cold War."

We knew, he says, that nuclear test sites and bomb production facilities in Russia and the United States were contaminated. We also knew about the waste left behind by civilian power reactors. We did not, however, expect to find the former republics strewn with radioactive sources after the demise of the Soviet Union.


Diego Lluma is a journalist based in Buenos Aires. He was a Bulletin Visiting Fellow last year.
 
©2000 The Bulletin of the Atomic Scientists