The governments of the Russia Federation and the United States (US) have embarked on a programme to use weapons-grade plutonium mixed oxide (MOX) fuel in nuclear reactors. In September 2000, an agreement between the US and Russia was reached for each side to render 34 metric tonnes (MT) of surplus weapons-grade plutonium unsuitable for nuclear weapons.

Weapons-grade plutonium disposition
According to a Federation of American Scientists’ Public Interest Report, 200-270MT of weapons-grade plutonium exited worldwide in 1996.¹ The USA was reported to have 85MT and Russia was estimated to have between 100-165MT, although the exact figure has never been made public. The end of the cold war and US-Russian disarmament agreements have resulted fissile material, plutonium and highly-enriched uranium (HEU) becoming redundant.²

A chief goal of plutonium disposition is to make weapons-grade plutonium cores recovered from deactivated nuclear warheads, or pits, inaccessible for nuclear weapons-making purposes. This should render the plutonium as inaccessible as the plutonium found in highly radioactive spent commercial fuel, thereby meeting the "spent fuel standard” defined by the National Academy of Sciences (NAS).³ To achieve this, the plutonium is combined with a gamma radiation source such as high-level waste. This process, known as immobilisation, transforms the plutonium into a quality similar to spent nuclear fuel, which is highly radioactive and difficult to handle. Both MOX irradiation and immobilisation were judged by the NAS to be comparable means of achieving the "spent fuel standard".⁴

Immobilisation
There are two methods of immobilising weapons-grade plutonium and disposing of it as waste: it can be immobilised in a glass matrix (vitrification) or a ceramic matrix (ceramification). The vitrification process involves contaminating plutonium with high-level radioactive liquid waste, which is then mixed with borosilicate glass to create a borosilicate matrix (glass logs). The logs are then sealed in stainless steel cylinders and stored for geological disposal at a nuclear waste repository. The ceramic immobilisation process uses a titanate matrix instead of a borosilicate matrix. Both these options create a highly radioactive environment for plutonium prior to geological disposal and meet the "spent fuel standard".

MOX irradiation
MOX-based plutonium disposition, or MOX irradiation, mixes recovered weapons-grade plutonium with uranium to form a mixed oxide, or MOX, fuel. The MOX fuel is then burnt (irradiated) in nuclear reactors, which can form a "closed fuel cycle" where the plutonium is irradiated, reprocessed and re-used. Irradiating MOX fuel in reactors produces more reactor-grade plutonium than the original MOX fuel because some of the uranium oxide in MOX transforms into plutonium.

The burning of weapons-grade plutonium from recovered pits could eliminate part of the fissile material stockpiles in the five declared nuclear weapons states belonging to the Non-proliferation Treaty (NPT). But Russia, as a nuclear weapons state, is under no legal obligation to put such activities under International Atomic Energy Agency (IAEA) verification. Nonetheless, the MOX irradiation of weapons-grade plutonium is being pursued by the US and Russia—backed by the nuclear industry—under the guise of nuclear disarmament.

Plutonium disposition in Russia
In 1995 the US declared 50MT of military plutonium surplus to its requirements and in 1997 Russia followed. On 1 September 2000, US Vice President Al Gore and Russian Prime Minister Mikhail Kasyanov signed the Plutonium Disposition Agreement committing each side to dispose of 34MT of surplus weapons-grade plutonium. The agreement is due to take place at an initial rate of 2 MT per year, commencing by December 2007, with the aim transforming excess weapons-grade plutonium into a form unusable for weapons. During the agreement it was decided that the US would burn 25MT of plutonium in MOX fuel and immobilise 9MT in high-level waste as part of its "dual track" disposition policy.

The agreement stipulated that Russia would burn all 34MT of surplus weapons-grade plutonium as MOX fuel. Russia has no commitment to dispose of plutonium through immobilisation with the decision not to immobilise was agreed by US negotiators. In the months of negotiations preceding the final agreement, Russia did offer 1MT of weapons-grade plutonium contained in low-assay sludge for immobilisation, but the offer was rebuffed by the US negotiators, which insisted that only high-assay materials were to be covered by the agreement.⁵

The agreement forbids either country from separating plutonium from irradiated MOX fuel until that party has disposed of all 34MT of plutonium. The initial cost estimates for the Russian programme were more than $1.7bn. To ensure that plutonium is irreversibly removed from use in nuclear weapons, the agreement specified that both parties would implement monitoring and inspection activities.

According to agreement, the Russian programme includes one industrial-scale site for MOX fuel fabrication, a test-fuel line for fabrication of initial VVER-1000 lead-test MOX assemblies, the modification of a facility for the fabrication of BN-600 pellet fuel and the completion of the Demonstration Conversion Facility.

In 2002, US-Russian officials completed a joint review of Russia’s plutonium disposition programme, following a year-long National Security Council review of US non-proliferation programmes in Russia. The joint review reportedly endorsed a new action plan that will engage PWRs and fast reactors in the disposition of weapons-grade plutonium, much like the initial programme. Four VVER-1000 PWRs at the Balakovo plant near Saratov will be used, as well as the BOR-60 experimental fast reactor near Dimitrovgrad and the BN-600 fast reactor near Yekaterinburg. The BN-600 operates on the basis of HEU and plutonium bearing fuels have only been tested. In February 2001, Minatom announced its intention to build a BN-800 fast neutron reactor at Beloyarsk NPP by 2009. The BN-800 is a modification of the BN-600, which could also be used for plutonium disposition.

However, Russian reactors may use a lower MOX core fraction than the US. In order to increase the plutonium disposition rate either the core fraction of Russian reactors will have to be increased or Russian MOX fuel would have to be exported. In other words, increasing Russia’s weapons-plutonium disposition rate to 4MT a year would require utilising additional reactor capacity.⁶ And according to the Nuclear Control Institute (NCI), Minatom’s reluctance to declassify the isotopic composition of weapons-grade plutonium means that this military plutonium will be blended with about 12% reactor-grade plutonium to conceal its isotopic composition before converting it to MOX fuel.⁷

The G8 and plutonium disposition
–> Under the 2001 agreement, however, the cost of the Russian plutonium disposition is to be covered by contributions from the G8 countries. At the 1996 Nuclear Safety and Security Summit in Moscow, the G8 initiated the "Programmes for Preventing and Combating Illicit Trafficking in Nuclear Materials”. This pledged to support efforts to ensure that all sensitive nuclear material (separated plutonium and HEU) was properly accounted for. The G8 began to identify possible means of international co-operation to address the management and disposal of plutonium not required for military purposes. And since 1996, the G8 have been examining both immobilisation and MOX irradiation as a means of dealing with weapons-grade plutonium disposition.

On 17 December 1999, the European Council established the "European Union Co-operation Programme for Non-proliferation and Disarmament in the Russian Federation". The G8 Plutonium Disposition Programme Group (PDPG) and the Non-proliferation and Disarmament Co-operation Initiative (NDCI) have in the past discussed European financing of Russian MOX. But while most of the G8 countries have embraced the MOX option for plutonium disposition in Russia on a rhetorical level, they have not been as eager to provide funding for the project.

The G8 foreign ministers’ joint statement from July 2000 pledged "to co-operate to establish multilateral arrangements necessary for a co-ordinated and integrated programme for the safe management and disposition of weapons-grade plutonium no longer required for defence purposes, and call on other states to join us [the G8] in supporting this effort." Still, the ministers did not make any financial commitments to pay for weapons-grade plutonium disposition.

At the G8 Summit in Canada in June 2002 the G8 nations agreed to fund a weapons-grade plutonium MOX fuel programme in Russia.⁸ The nations pledged to raise to up $20bn over ten years to support non-proliferation programmes as part of "The G8 Global Partnership against the Spread of Weapons and Materials of Mass Destruction”, including plutonium disposition in Russia.⁹ In the past, though, the US has been unsuccessful in raising any of the $2bn cost for the Russian MOX programme from the other G8 nations.¹⁰ This being the case, the future of G8 non-proliferation assistance to Russia looks uncertain.

Furthermore, in January 2002 the Bush administration decided to indefinitely suspend the development of immobilisation. It has ordered the dismantling of the Plutonium Ceramification Test Facility at Lawrence Livermore National Laboratory, which was due to test the process for incorporating weapons-grade plutonium into ceramic pucks. The US will now focus on the MOX fuel track and will now proceed with the MOX irradiation of weapons-grade plutonium in parallel with Russia. In its rejection of the bipartisan US policy that opposed the commercial trade in plutonium and closed fuel cycles, the support for the MOX programme reflects a fundamental change in US non-proliferation policy.

Problems with MOX irradiation
Problems with irradiating MOX fuel in nuclear reactors can be broken down into costs, reactor safety issues and fissile material diversion leading to proliferation.

Costs associated with MOX fabrication
The US Department of Energy estimates that the cost of MOX based plutonium disposition in Russia is around $2bn including the cost of building and operating the MOX fuel plant. The cost of disposing of Russia’s surplus weapons-grade plutonium could be reduced to $1bn if one or more Western European countries that already use MOX fuel were willing to purchase Russian MOX fuel.¹¹

According to Frank von Hippel, roughly $700m would be required for research and development and design and construction facilities to convert the plutonium from metal oxide and produce the MOX fuel. This figure includes transportation and storage infrastructure. An additional $1bn would be needed to operate the MOX plant. At 4% plutonium content, 34 MT of plutonium would be turned into MOX fuel with 850MT of heavy-metal content. This plutonium would displace lightly-enriched uranium (LEU) fuel worth roughly $1,000 a kilogramme.¹² What is more, MOX fuel is 3-5 times more expensive to produce than LEU fuel.

A joint US-Russian government study concluded that a MOX fuel plutonium disposition programme in Russia would cost up to $2.5bn, though this does not include the cost of upgrading Russian VVER-1000 reactors to Western safety standards. Doubts over the availability of funding have led Minatom to consider the leasing of MOX fuel to reactors outside of Russia. Minatom has made proposals to lease to Western Europe and East Asia MOX fuel produced in Russia from warhead plutonium.¹³ The MOX fuel would remain the property of Russia. Once used, the SNF would be shipped back to Russia for reprocessing or disposal. This would delay the shut down of Western reactors, which would receive subsidised fuel and be able to send SNF to Russia for reprocessing.

MOX fuel and reactor safety
The use of MOX fuel carries risks that apply to both reactor-grade and weapons-grade MOX fuel and can jeopardise reactor safety. What is more, there is no experience anywhere with the use of weapons-grade plutonium in MOX fuel. The substitution of MOX fuel for lightly-enriched uranium (LEU) in LWRs raises safety risks that have not been adequately assessed. Concerns with operating breeder reactors with MOX fuel exist. Breeder reactors are cooled with sodium, which becomes volatile when it comes into contact with water and air. BN-600 has already had a sodium accident, despite having Russia’s best nuclear safety record.

The likelihood of severe accidents would increase with using MOX fuel. The introduction of MOX fuel into LWRs reduces the effectiveness of the materials used to absorb neutrons in the core, such as control rods and the boron dissolved in the coolant. This makes it more difficult to control the nuclear reactions in the core and reduces the margin available to safely shut down the reactor. The "delayed neutron fraction", a constraint determining the speed at which the power level of the reactor responds to changes in conditions, is small when MOX fuel is used in LWRs. This means that the operator has less control over reactor transients, as well having less time to respond to them.

Using MOX fuel in a reactor core would increase the affects of a severe accident involving containment failure or containment bypass because MOX cores have higher concentrations of actinides, including isotopes of americium, curium and plutonium. Most of these are alpha-particle emitters with radio-toxicities. In the event of a severe, Chernobyl-type accident with containment failure or bypass at a PWR with a 40% weapons-grade MOX core, the number of latent cancer fatalities would be around 25% higher than for a PWR with an all LEU core. The NCI finds that the use of MOX fuel could have serious negative effects on other aspects of PWR operation such as overcooling transients and pressurised thermal shock, which is of concern to VVER-1000s.¹⁴ It would cost $120m-$180m to upgrade each VVER-1000 reactor to meet Western safety standards.

MOX diversion and proliferation risks
Bellona believes that a MOX fuel programme in Russia would increase plutonium proliferation risks. One of the main problems with using MOX fuel on a commercial scale is that it will result in the increased transport of plutonium and fresh MOX fuel. Both the plutonium and fresh MOX fuel would be a very tempting target for terrorist groups or "rogue states" that would like to develop nuclear weapons. The 1987 Edition of the "IAEA Safeguards Glossary" classifies MOX fuel as a "direct-use material".¹⁵ Plutonium could be extracted from MOX fuel in 1 to 3 weeks and then be used for weapons purposes.

MOX fuel disposition would provide Russia with a technical infrastructure to develop a plutonium-based "closed fuel cycle" for its civilian nuclear programme. Minatom has also retained the option to reprocess its irradiated weapons-grade plutonium MOX fuel after the end of the disposition programme. It is possible that weapons-useable plutonium could be separated by reprocessing and re-used in the fabrication of a nuclear weapon. Moreover, large-scale MOX fuel production and transportation also carries with it the threat that fresh MOX fuel could be stolen and diverted to other uses. After all, warhead-derived MOX fuel is merely plutonium and uranium blended and held in ceramic form. It can be dissolved and the two elements separated out, one of which is heavier than the other.¹⁶ In fact, reprocessing requires the SNF to be dissolved in nitric acid whereby uranium, plutonium and radioactive waste are separated. This process produces uranium powder and plutonium powder, the latter used for MOX fuel.

A report by Frank Barnaby for the Oxford Research Group concluded that it would be relatively easy for a terrorist group to make a nuclear device based on plutonium from fresh MOX fuel.¹⁷ Dr Barnaby, a physicist who worked for Britain’s nuclear weapons laboratory at Aldermaston, outlined three methods of chemically separating the plutonium dioxide from the uranium dioxide in MOX fuel. What is more, the US Department of Energy came to the conclusion that: "fresh MOX fuel remains a material in the most sensitive category because plutonium suitable for use in [nuclear] weapons could be separated from it relative easy”. Moreover, an article by Henry Sokolski, executive director of the Non-proliferation Policy Education Center, who served in the Department of Defense under Bush Senior, suggested the US government is risking the spread of plutonium around the world by supporting the disposition of weapons-grade plutonium as MOX fuel.¹⁸

Another problem associated with MOX fuel is connected with breeder reactors. While the BN-600 reactor would be operated without a "blanket" so it will not breed more plutonium, it could in fact be operated in breeder mode. More worrying, perhaps, is Minatom’s pursuit of a new, larger fast breeder reactor, the BN-800. This could lead to a plutonium-based "closed fuel cycle" and increase separated plutonium stockpiles. By subsidising Minatom’s plutonium economy, the G8 might inadvertently contribute to proliferation risks instead of reducing them.

Conclusion
The best solution for surplus weapons-grade plutonium is to convert it into the "spent fuel standard" by means of immobilisation. Immobilisation requires far less resources than MOX irradiation (industrial infrastructure, fuel fabrication, handling, shipment). Immobilisation has the advantage of keeping the plutonium under state control at designated sites. This makes physical protection much easier. Immobilisation also makes the recovery of nuclear weapons-usable plutonium difficult. Besides, in the post-11 September 2001 security environment, immobilisation would remove weapons-useable material from circulation.

Bellona believes that preventing nuclear proliferation is one of the most urgent tasks facing the world and the use of MOX fuel would add to proliferation risks. Surplus weapons-grade plutonium should be converted into the "spent fuel standard" by immobilising the plutonium with high-level waste prior to geological disposal.

Notes
1. Frank von Hippel, ‘Recommendations for Preventing Nuclear Terrorism’, Journal of the Federation of American Scientists, Public Interest Report, Vol.54, No.6, Nov/Dec 2001, FAS
2. Prof. J. E. Harris, ‘Disarmament and disposal of fissile material’, Interdisciplinary Science Reviews, 1998, Vol.23, No.3.
3. Committee on International Security and Arms Control (CISAC), National Academy of Sciences, ‘Managing and Disposition of Excess Weapons Plutonium: Reactor-Related Options’, National Academy Press, 1995.
4. See the Nuclear Control Institute: Plutonium Disposal Section, NCI
5. Edwin S Lyman, ‘The Future of Immobilisation under the US-Russian Plutonium Disposition Agreement’, NCI, July 2001, NCI
6. NCI. Ibid
7. Edwin S Lyman, ‘The Safety Risks of Using Mixed-Oxide Fuel in VVER-1000 Reactors: An Overview’, NCI, May 2000, NCI
8. See the G8 Summit: the G8 Summit
9. See Bellona’s Position Paper on ‘The G8 Global Partnership against the Spread of Weapons and Materials of Mass Destruction’.
10. NCI. ‘G8 Nations to Waste Billions on Dangerous Russian Plutonium Fuel’, 27 June 2002, NCI
11. FAS. Ibid
12. FAS. Ibid
13. Greenpeace Briefing, ‘The Disarmament Myth of Plutonium Fuel Production’, March 2001.
14. Edwin S Lyman, ‘Public Health Consequences of Substituting Mixed-Oxide Fuel for Uranium in Light-Water Reactors, NCI, January 1999, NCI
15. The International Atomic Energy Agency "IAEA Safeguards Glossary", 1987. See points 46, 49 and 105.
16. CND, UK, Briefing Paper, Mixed Oxide Fuel: some answers to some questions, CND
17. Stuart Miller, ‘Scientists says BNFL plant is terrorist risk’, 31 May 2001, the Guardian
18. The Non-proliferation Policy Education Center, NPEC