Iran's Nuclear Activities
Dr. Frank Barnaby,
Nuclear Activities (pdf)
The major powers - particularly, Europe,
Japan, Russia and the USA - suspect that Iran is clandestinely
developing nuclear weapons. Firm evidence for this suspicion
comes mainly from the International Atomic Energy Agency
(IAEA). Nuclear-weapon activities in Iran are not new
- in fact, they date back to the days of the Shah who
had ambitions to acquire a nuclear force. But today's
Iranian government insists that its nuclear activities
are solely related to its civil nuclear programme and
that it is not developing nuclear weapons.
The IAEA has announced that Iran is building two plants
at Natanz to enrich uranium and is constructing a heavy-water
reactor in Arak. The Iranian government has acknowledged
the existence of these two previously secret facilities
but claims they are part of its civil nuclear programme
and not part of a military nuclear-weapon programme.
The Iranian government, however, admitted to these activities
only after the National Council of Resistance, an Iranian
opposition group, announced that they were underway.
Both of the uranium enrichment and the heavy water
production plants raise concerns. A heavy-water reactor
is a particularly efficient way of producing plutonium
for use in nuclear weapons. A uranium enrichment plant
can produce the highly enriched uranium needed for nuclear
Many argue that because Iran has enormous reserves
of oil and gas it does not need nuclear energy and that
its nuclear programme demonstrates ambitions to produce
nuclear weapons. Iran claims that it needs to export
as much of its oil as possible to earn much needed foreign
currency, that its oil reserves are finite and that
nuclear power is a sensible investment for the future.
Iranian Nuclear Activities
Apart from the heavy water and uranium enrichment plants,
there are other Iranian nuclear activities that raise
suspicions. These include:
The IAEA has also discovered that Iran has in the past:
- imported uranium hexafluoride gas to test gas centrifuges
at the Kalaye Electric Company, thereby producing
some enriched uranium;
- imported uranium metal for use in laser enrichment;
- produced uranium dioxide, uranium hexafluoride,
and a number of other uranium compounds using imported
uranium dioxide; and
- produced uranium dioxide targets at ENTC and irradiated
them in the Tehran Research Reactor (TRR). The targets
were then processed in hot cells to separate the plutonium.
Iran violated its Safeguards Agreement with the IAEA,
required by the Non-Proliferation Treaty (NPT), by failing
to report many of these activities to the Agency as
the Safeguards Agreement requires. Disclosures by Iran
of its nuclear programme show that it had concealed
many of its nuclear activities, and consequently violated
its obligations under the Safeguards Agreement and the
Iran has signed an Additional Protocol to its Safeguards
Agreement with the IAEA but the Iranian parliament (the
Majlis) has not yet ratified it. The Additional Protocol
permits the IAEA improved access to Iran's nuclear facilities,
including the collection of environmental samples.
These violations are the basis of the international
suspicions that Iran is secretly developing nuclear
weapons. None of these activities are in themselves
illegal; it is the failure to report them to the IAEA
that is illegal.
Because of its long experience in nuclear physics and
engineering and because it has been operating nuclear
research reactors for decades, Iran has a cadre of trained
personnel that could be switched to a nuclear-weapon
programme. If it produces the fissile material - highly-enriched
uranium or plutonium - needed for nuclear weapons it
could fabricate them in a relatively short time.
Iran's Current Nuclear Activities
It is common knowledge that Iran has a civilian nuclear-power
reactor under construction. The Russians are building
the 1,000 megawatt-electrical light-water reactor at
Bushehr. It will use low enriched (about 3.5 percent
in uranium-235) as fuel. Under the contract Iran has
with Russia, Russia will provide the fuel for the lifetime
of the reactor and will take back to Russia the spent
fuel for storage and possibly reprocessing.
This power reactor is, according to Iran, the first
of a series of power reactors planned to generate 6,000
megawatts of electricity. Iran explains that it is interested
in establishing a capability to produce low-enriched
uranium so that it has an indigenous supply of nuclear
Iran operates four research reactors, three at the
Estahan Nuclear Technology Centre and one at the Nuclear
Research Centre in Teheran. Two, at Estahan, are sub-critical
assemblies used for training nuclear physicists and
technicians; they have both been operating since 1992.
The third at Estahan is a 30-kilowatt research reactor
used for research purposes; it has been operating since
1994. The fourth is a 5 megawatt-thermal reactor also
used for research; it has been operating since 1967,
an indication of the length of time during which Iran
has been interested in nuclear technology.
The two facilities suspected of being part of a nuclear-weapon
programme are: a plant to produce heavy water, located
near the town of Arak, about 250 kilometres from Teheran;
and two gas centrifuge plants under construction at
Natanz, 40 kilometres from Kashan. One is a Pilot Fuel
Enrichment Plant (PFEP) and the other is a large commercial-scale
Fuel Enrichment Plant (FEP). Iran has acknowledged that
components for gas centrifuges have been produced in
the workshop of the Kalaye Electric Company in Tehran.
PFEP will apparently contain about 1,000 centrifuges
and may already be completed. Iran plans to install
more than 50,000 centrifuges at the commercial scale
FEP; installation of centrifuges is scheduled to start
in early 2005.
Uranium hexafluoride gas was introduced into the first
centrifuge at PFEP in June 2003 to test a single centrifuge.
In August 2003, Iran began testing a ten-centrifuge
cascade with uranium hexafluoride gas.
Heavy water production
Heavy water (water in which the hydrogen is the deuterium
isotope) is an excellent moderator and coolant for a
reactor fuelled with natural uranium. Such a reactor
is excellent for the production of plutonium of a grade
suitable for use in very effective nuclear weapons (so-called
weapon-grade plutonium). The Dimona reactor used by
Israel to produce plutonium for its nuclear weapons
is a heavy water-natural uranium reactor, as is the
Cirus reactor used by India produce plutonium for its
Heavy water and enriched uranium can both be used in
a civil nuclear-energy programme; they are dual-purpose
materials. For example, the Candu-type nuclear-power
reactor developed and used by Canada uses heavy water
and a gas-centrifuge plant can produce the low-enriched
uranium needed to fuel civil nuclear power reactors.
Iran claims that it wants to replace the aged (35-year
old) Tehran Research Reactor and plans to do so by building
a new heavy water reactor, called the IR-40, at Arak.
The IR-40 will be a 40-megawatt (thermal) reactor cooled
with heavy water. According to the IAEA, Iran plans
to manufacture the fuel (uranium dioxide) elements for
the IR-40 in the Fuel Manufacturing Plant (FMP) to be
built at the Esfahan establishment. Iran says that the
purpose of the IR-40 reactor is the production of radioactive
isotopes for medical and industrial uses.
Iran says that about 85 tonnes of heavy water will
be initially required for IR-40 and less than 1 tonne
will be need annually. Iran is constructing a heavy
water plant at Khondab near Arak with an initial capacity
of 8 tonnes of heavy water per year. Apparently, a second
production with a similar production capacity is under
Uranium enrichment using gas centrifuges
The production of heavy water on a reasonable scale
is a much easier task than producing significant amounts
of highly enriched uranium in a gas centrifuge plant.
The capacity of a gas centrifuge is measures in separative
work units (SWUs). A reasonable estimate is that each
centrifuge of the type that Iran is likely to produce
(most likely made from carbon fibre) would have a capacity
of about 2.5 SWU per year. That this is likely is indicated
by the example of Iraq. In 1991, Iraq had a prototype
centrifuge with a carbon-fibre rotor spun at up to 60,000
rpm (a wall speed of roughly 450 meters per second).
The enrichment capacity during the best test run reached
1.9 SWU per year. IAEA inspectors estimated that an
output of 2.7 SWU per year could have eventually been
An Iranian facility containing, say, 3,000 centrifuges
could produce 7,500 SWU per year or about 40 kilograms
of highly enriched uranium per year. It would take this
facility at least 5 years to produce enough highly enriched
uranium for the nuclear force of six nuclear weapons.
With sufficient expertise in HEU-based nuclear weapons,
40kg per year could provide two nuclear weapons.
Assuming that about 60 per cent of the centrifuges
have to be rejected as sub-standard, a reasonable assumption,
Iran would need to produce about 5,000 centrifuges for
the facility. Moreover, gas centrifuges break down frequently
because of the mechanical stresses they are under. A
steady supply of replacement machines must, therefore,
A facility operating a cascade of 3,000 centrifuges
would use as much energy, electrical power, as a largish
city - approximately 200 kilowatt-hours per SWU or roughly
1,000 kilowatt-hours per gram of highly enriched uranium.
It would, therefore, be impossible to operate such a
facility clandestinely. Building and operating effectively
a gas centrifuge facility of a useful size is not a
trivial task - it is an industrial undertaking. It would
probably take Iran at least four or five years to build
such a facility and begin producing significant amounts
of highly enriched uranium.
For use as the fissile material in nuclear weapons,
uranium must be enriched to more than 90 percent in
the isotope uranium-235. Iran claims that its needs
uranium enriched to between about 3 and 5 per cent for
use in its civil nuclear power programme. But most of
the energy needed to achieve enrichments of more than
90 per cent in uranium-235 is used to reach an enrichment
of up to about 5 per cent. It is, therefore, very advantageous
to use low-enriched uranium as the feed material to
produce weapon-grade uranium. The low enriched uranium
would simply be passed a few times through the enrichment
Laser isotope separation (LIS)
Uranium can be enriched using a laser method called
laser isotope separation (LIS). LIS separates uranium
isotopes more efficiently than gas centrifuges because
it is based on the fact that each isotope of an element
has a unique set of electronic energy states. Consequently,
electrons of atoms of each isotope will absorb light
of a specific colour (i.e., of a specific energy level).
If illuminated by a laser beam containing light of this
precise colour, electrons of atoms of the selected isotope
will absorb photons and become excited. An atom may
give up its excited electron, and become a positively
charged ion. The atoms of the other isotopes will not
absorb photons, because they do not have the 'right'
energy, and will not be ionised. The ionised atoms can
be separated from the neutral ones by an electromagnetic
The Iranians have experimented with an Atomic Vapor
Laser Isotope Separation (ALVIS) system that consists
of two main units - a separator and a laser. When used
to separate uranium isotopes, natural uranium metal
is vaporised in the separator, using an intense electron
beam that creates a uranium vapour stream in a vacuum
chamber that rapidly moves away from the uranium metal.
The vapour contains atoms of U-235 and U-238.
The laser unit uses powerful copper-vapour lasers that
emit beams of green-yellow light. This light energizes
(excites) 'dye' lasers that emit beams of red-orange
light of precisely the right colour (i.e., frequency)
to photoionise preferentially U-235 atoms. The red-orange
beams are passed through the vapour of uranium atoms.
U-235 atoms absorb photons of the red-orange light
whereas U-238 atoms do not. The excited U-235 atoms
eject the excited electrons, becoming ionised; the U-238
atoms remain untouched. An electromagnetic field moves
the positively charged U-235 atoms to a collecting plate
where they condense. The enriched U-235 can then be
removed. The remaining uranium vapour, containing a
much greater proportion of U-238 than natural uranium,
flows on through the separator chamber and is removed.
The ALVIS photoionisation process has an atomic selectivity
of more than 10,000 - only one ion of U-238 is produced
for every 10,000 ions of U-235. This high enrichment
efficiency, combined with the fact that relatively little
energy is needed to operate the separator and laser
systems, makes the operating and capital costs of the
ALVIS process relatively low. This makes laser-isotope
separation appear more attractive than other enrichment
Iranian laser enrichment research and development and
the manufacture of copper vapour lasers have been undertaken
in a laboratory located at Lashkar Ab'ad. A pilot plant
for laser enrichment was established at Lashkar Ab'ad
in 2000 and, the Iranians claim, dismantled in 2003.
The Iranian government has acknowledged to the IAEA
that it has irradiated uranium dioxide targets with
neutrons in the Tehran Research Reactor and subsequently
chemically separated the plutonium produced in the targets.
According to the Iranians, only a small amount of plutonium
If the heavy water reactor being constructed at Arak
is used to produce plutonium for use in nuclear weapons,
it will be necessary to chemically separate the plutonium
from the irradiated reactor fuel elements. The experiments
performed by the Iranians in plutonium separation are,
Iran is developing a number of nuclear technologies
that are duel purpose - they could be used for civil
or nuclear activities or in nuclear weapon programmes.
These technologies are associated, firstly, with the
enrichment of uranium and, secondly, with the construction
of a heavy water reactor. The enrichment activity may
lead to the production of low enriched nuclear fuel
suitable for use as nuclear fuel in the civil nuclear-power
reactors that Iran intends to operate and/or the production
of highly enriched uranium for use as the fissile material
in nuclear weapons.
The IR-40 heavy water reactor being constructed by
Iran will, it says, produce radioactive isotopes for
medical and industrial uses. But the reactor could also
be used to produce effectively plutonium that could
be used to fabricate nuclear weapons. IR-40 could produce
about 8 kilograms of plutonium a year, enough to produce
two nuclear weapons a year.
Iran has been involved in nuclear technology for a
long time - 40 years or so. It therefore has a strong
cadre of nuclear physicists and engineers that could
be diverted to design, develop and fabricate nuclear
weapons if Iran's political leaders took the decision
to do so. What Iran does not have today is significant
amounts of fissile material - highly enriched uranium
or plutonium - needed to produce nuclear weapons.
The activities now underway in Iran could, however,
eventually provide Iran with such fissile material.
Iran would then be able to deploy rapidly a nuclear
weapons force if it takes the political decision to
do so. Iran has ballistic missiles that could deliver
nuclear warheads. Hence, the international concern about
Iran's current nuclear activities.
Are these activities explicable as part of a civil
nuclear programme to generate electricity and produce
isotopes for peaceful purposes? The only other explanation
is that they are part of a nuclear-weapon programme.
It should, however, be emphasised that there is no
firm evidence that Iran intends to fabricate nuclear
weapons. As reported in the International Herald
Tribune on 6th November 2004, Mohamed El Baradei,
Director General of the IAEA, said: "We haven't
seen any concrete evidence that points to a fact that
Iran has a nuclear weapons program" although he
went on to say: "We have seen Iran experimenting
with all aspects of the [nuclear] fuel cycle".
Three European major powers - Britain, France and Germany
- are currently trying to persuade Iran to give up some
of those dual nuclear activities that they suspect may
be being used by Iran in a nuclear-weapon programme.
In particular, they seek suspension of all Iranian activities
related to uranium enrichment until a long-term agreement
is negotiated on Iran's nuclear programme as a whole.
Iran wants any suspension to be limited to six months
and for some enrichment activities to be exempted from
In return for a suspension of its whole enrichment
programme, the European countries are, in the latest
negotiating move, offering Iran some civil nuclear technology
and materials, including a (light-water) research reactor
and a supply of nuclear fuel, as well as increased trade
and assistance with reductions of Iran's regional security
concerns. The Bush Administration would prefer that
the nuclear activities in Iran be referred to the UN
Security Council for discussion. Time will tell whether
or not the negotiations succeed.
Frank Barnaby is the Nuclear Consultant
to Oxford Research Group and a freelance defence
Nuclear Activities (pdf)
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