The most detailed official government description of Canada's W-Pu disposition MOX initiative I have seen so far has recently been posted at
PLUTONIUM MOX FUEL INITIATIVE
© Department of Foreign Affairs and International Trade, September 2, 1999
Much of the excess weapons-usable plutonium in Russia and the United States (U.S.) presents a clear and present danger to world peace and security because it can be re-made into nuclear weapons. Canada is willing to consider the use of MOX fuel - consisting of a mixture of plutonium oxide and uranium oxide - in Canadian-based CANDU reactors because it would help ensure that this weapons-grade plutonium would never again be used in nuclear weapons.
Worldwide attention is focused on addressing the safety and security of Russian and U.S. surplus weapons plutonium so that the risks of diversion to rogue states or terrorist organizations can be minimized. The U.S. and Russia are studying options for reducing their inventories of surplus weapons plutonium; one option of interest involves using the mixed oxide (MOX) fuel in Canadian CANDU reactors. This option would involve the fabrication outside Canada of MOX fuel bundles, containing up to about 3 percent plutonium, and the transport of this fuel to Canada to be used in CANDU reactors for the generation of electricity.
Non-Proliferation Considerations and Objectives
With the end of the Cold War, Russia and the U.S. agreed to reduce the nuclear warheads in their arsenals by nearly 75 percent. It is expected that, by the year 2003, approximately 40,000 nuclear warheads will have been dismantled and each country will have more than 50 metric tonnes of weapons-grade plutonium surplus to their defence needs.
The U.S. and Russia are examining strategies for the disposition of this surplus weapons plutonium. The technologies being assessed to ensure the earliest implementation include plutonium immobilization using glass (vitrification) or ceramics and consumption as fuel in civilian nuclear generating stations.
At the April 20, 1996, Moscow Summit on Nuclear Safety and Security, G-7 and Russian leaders agreed that international cooperation is needed for the safe management and use of plutonium no longer required for defence purposes. The Prime Minister, the Right Honourable Jean Chrétien, noting the possible positive benefits to non-proliferation by reducing plutonium stockpiles, announced that Canada had agreed, in principle, to the concept of using MOX fuel in Canadian-based CANDU reactors. Studies and assessment of the CANDU option by Atomic Energy of Canada Limited (AECL) and Ontario Hydro (now Ontario Power Generation Inc. - OPG) in collaboration with U.S. and Russian experts have continued since 1994. Canada has a long history of promoting international non-proliferation measures and encouraging disarmament. Canada shares the concern of the international community that plutonium, a key component of nuclear weapons, must remain inaccessible to rogue states or organizations. The vast amount of plutonium that will accrue from the nuclear weapons dismantlement programs will present a challenge for the continued physical security and accountability of this material.
Responsibility for the safe and secure storage and disposal of military fissile material rests with the nations that produced it. However, Canada agrees with the need for international attention to address the various arrangements that could effectively reduce the stockpiles of plutonium in nuclear weapons states, particularly if this can be accomplished in a productive manner by using some of the contained energy in plutonium for peaceful economic gain. The safe and secure use of MOX fuel in a nuclear station for the generation of electricity would meet the objective of transforming swords into ploughshares.
The U.S. and Russia anticipate the concurrent reduction of their respective stockpiles of weapons plutonium. Both have indicated interest in the participation of a trusted third party, such as Canada, since it could assist in providing the assurances needed for managing MOX fuel from both countries. The final U.S. Programmatic Environmental Impact Statement (PEIS) on the Storage and Disposition of Weapons-usable Fissile Materials issued on December 9, 1996 stated that the U.S. Department of Energy (DOE) "would retain using MOX fuel in CANDU reactors in Canada in the event that a multilateral agreement to use CANDU reactors is negotiated among Russia, Canada and the U.S.A.". Provided that the CANDU MOX initiative can be implemented safely and economically, the parallel draw-down of Russian and U.S. weapons-grade plutonium would provide an opportunity for a significant Canadian contribution to the cause of non-proliferation of nuclear weapons.
The CANDU MOX fuel initiative is based on the use of plutonium drawn exclusively from the nuclear weapons programs in the U.S. or Russia and will not include the use of any plutonium reprocessed from spent fuel. Each country has declared significant amounts of plutonium (of the order of 50 tonnes) surplus to defence needs. AECL and Ontario Hydro, have indicated that MOX fuel made from the weapons plutonium could be utilized in Ontario Hydro nuclear reactors.
The U.S. has been investigating methods to dispose of its weapons-grade plutonium for several years. The U.S. National Academy of Sciences described the stockpiles of plutonium as a "clear and present danger" and recommended that the development of a permanent disposal solution should be given top priority. In an initial comprehensive study on the advantages and disadvantages of disposition options, the Academy identified the use of MOX fuel in existing Canadian CANDU reactors as one of the most promising disposition options. The finding prompted the U.S. DOE to undertake an initial feasibility study of the CANDU option. AECL and Ontario Hydro undertook this study in 1994, under the sponsorship of the U.S. DOE in its study of options for the Storage and Disposition of Weapons-Usable Fissile Materials. This study indicated that MOX use as a fuel in a CANDU reactor is technically feasible. It also indicated that the manufacture of CANDU MOX fuel bundles in the U.S. and their safe and secure transportation to Ontario Hydro Bruce Nuclear Generating Station on Lake Huron in Canada were feasible.
The criterion for final plutonium disposal established by the U.S. DOE is called the Spent Fuel Standard. Its objective is to ensure that the plutonium from weapons is as inaccessible and as unattractive for retrieval and weapons use as the residual plutonium in spent fuel from commercial reactors. The Spent Fuel Standard has been recognized by G-7 and Russian experts as being the acceptable international criterion at their meeting in October 1996.
The factors and criteria used in the U.S. study included:
resistance to theft and retrieval;
resistance to retrieval and reuse by the host nation;
compliance with environment, safety and health regulations;
fosters progress and cooperation with Russia and other countries;
public and institutional acceptance.
In announcing the results of the PEIS on December 9, 1996, the U.S. Secretary of Energy stated that a dual-track strategy would be pursued using two technologies, (a) the plutonium immobilization using vitrification (glass) or ceramics and (b) consumption of MOX fuel in existing reactors. Both U.S. Light Water Reactors (LWRs) and the Ontario Hydro CANDU reactors were included in this category.
In response to Russian interest to possibly provide CANDU MOX fuel, a similar joint study was undertaken with the Ministry of the Russian Federation for Atomic Energy (Minatom). The study entails the feasibility of manufacturing CANDU MOX fuel bundles in Russia with weapons plutonium declared surplus to Russian defence needs, and then transporting the fuel to Ontario Hydro nuclear reactors. This study confirmed that by combining a CANDU MOX fuel line to a planned Russian reactor MOX fuel fabrication facility was feasible and was economical to do so. This study by AECL, Ontario Hydro and the Canadian fuel supplier, Zircatec Inc. in collaboration with Russian nuclear engineers, was funded by the Canadian International Development Agency, under its technical assistance program for Russia.
Use of Plutonium in CANDU
The reference fuel cycle for CANDU reactors is once-through natural uranium. As in other fission reactors, plutonium is produced from the uranium fuel by irradiation during the normal operation of the reactor. The fissile U-235 content of naturally occurring uranium is supplemented by conversion of some U-238 to fissile Pu-239. In fact, the fission of plutonium contributes about half the energy produced by the CANDU fuel bundles during the normal course of operation of the reactor.
The traditional fuel cycle for CANDU reactors uses fuel bundles that consist of an assembly of fuel elements containing natural uranium oxide fuel pellets. The MOX fuel bundle would have the same geometry as the normal natural uranium fuel bundle. However, the fuel pellets inside the fuel elements of the MOX fuel bundle would contain a small amount of plutonium.
While natural uranium is the only fuel being supplied to CANDU reactors around the world, AECL has considerable experience in the research of different fuel cycles, including plutonium. Research work has shown that mixed oxides of plutonium and depleted uranium can be satisfactorily used in the CANDU reactor. The depleted uranium is a product from the enrichment process for light water reactors.
Canadian Government policy does not exclude the use of plutonium as a reactor fuel, but the cost of producing plutonium makes it an uneconomic alternative to natural uranium for the CANDU reactor. In this instance, however, the plutonium has already been produced for weapons purposes and a key factor in the selection of an appropriate disposition alternative is the economic cost involved. Using surplus-weapons plutonium as a CANDU MOX fuel in a productive revenue-generating endeavor, such as the generation of electricity, is viewed as a serious option with the potential of economic benefits relative to direct disposal.
CANDU MOX Fuel Manufacture
The plutonium declared surplus from U.S. and Russian weapons programs would first be converted into plutonium oxide by the respective governments, and then combined with depleted uranium oxide to make mixed oxide fuel or MOX. The MOX would be made into fuel pellets, which would then be assembled into CANDU fuel bundles. The U.S. material is under civilian (DOE) control now. The subsequent steps involved in fabricating the fuel would be completed under applicable verification procedures and international safeguards control in the U.S. and in Russia, before being shipped to the purchaser in Canada. As is normally done, the quality control and manufacturing procedures for the supply of CANDU fuel bundles would be assessed and approved by the CANDU fuel purchaser. The only significant difference between the CANDU MOX fuel bundle and the CANDU natural uranium fuel bundle is that the fuel pellets in the MOX fuel bundle would contain up to about 3 percent plutonium oxide.
Fuel Testing Program
As an important first step in assessing the remaining options before a final decision can be made, the U.S. is financing initial tests on small samples of CANDU MOX fuel, manufactured from U.S. and Russian weapons plutonium. Since the Chalk River NRU research reactor has been used extensively to confirm the performance of similar nuclear fuel in the past, AECL has agreed to conduct these tests. The tests are expected to begin in the autumn of 1999 and will take several years to complete. In light of the keen public interest in this subject, the Atomic Energy Control Board (AECB) will be assessing details of the AECL test program to ensure that it is in within the operating envelope of the NRU reactor and in compliance with the site license authorized by the AECB.
Transport, Handling and Use of CANDU MOX Fuel
The transport, handling and use of CANDU MOX fuel bundles at an Ontario Power Generating Inc. nuclear power plant are not expected to pose any unacceptable security or safety risks. However, these factors are the subject of future study and would be reviewed in detail by the AECB as part of the licensing process. Transport Canada is equally responsible to assess and approve the Emergency Response Assistance plans for transportation of this fuel .
Should the CANDU option be ultimately selected, approval to actually implement the project would be subject to the full process of regulatory licensing and public review according to the legislative requirements of Canadian federal and provincial authorities.
The composition of the spent fuel produced by the MOX fuel would be similar, though not identical to, that which is currently being produced using natural uranium. Studies of possible MOX fuels have shown that, although the proportion of the fissile plutonium is somewhat higher than the residual plutonium (0.3 percent) found in natural uranium spent fuel, it would not exceed 1 percent of the products in the spent fuel.
There is, however, a net destruction of the plutonium, which, in addition to the dilution of the fissile plutonium due to the generation of non-fissile plutonium isotopes, reduces the desirability of the residual plutonium for weapons purposes. Further, the high radiation levels from the fission products contained in the discharged fuel bundles provide a self-protecting radiation barrier. Any attempt to use spent fuel as a source of plutonium for weapons purposes would require significant time, resources and technology to separate the fissile plutonium from the fission products. In addition, the international safeguards measures that are already in place to secure and monitor the spent fuel from Canadian reactors would also be applied to the spent MOX fuel. While management and storage of spent fuel would be handled in the same way, the amount produced from MOX fuel will be about 15 percent less [correction: 68% less, according to Parallex program manager D. Cox, based on 25MWd/kg burnup ] than that from the use of natural uranium fuel to generate the same amount of electricity.
Fuel Supply Contract
The price and terms of MOX fuel supplies would be the subject of negotiation between the utility, Ontario Power Generating Inc., and the fuel suppliers in the U.S. and Russia. This initiative would be confined to the possible use of existing weapons plutonium only, and would not be related to any commercial plutonium fuel cycle. Any final arrangements and contracts would be based on mutually agreed upon terms and would be designed to balance the equities, obligations and objectives of all the parties.
The Canadian Government applauds efforts to elimination of nuclear weapons and has long urged such action. If the use of CANDU reactors can help ensure that material such as plutonium will never again be reassembled into nuclear weapons, the Government believes that a MOX fuel project involving CANDU reactors should be given serious consideration and has given its approval in principle to the concept and to further studies and tests. However, it should be noted that the use of MOX fuel in Canadian-based reactors would not be subsidized by Canadian Government funds.
The CANDU initiative may be subject to further technical assessments, economic studies and tests in collaboration with the Governments of the U.S. and the Russian Federation over the next two years. The CANDU and other international MOX programs are still in the early development phase. These international programs will have an impact on the CANDU MOX initiative, especially when addressing the Russian situation. It is expected that the U.S. and Russia will make final decisions in the next 1 to 2 years on specific projects to be employed. It is only then that, if Canadian are chosen by the nuclear weapons states, firm project proposals can then be presented to the Canadian and Ontario Governments and regulatory authorities for final consideration and approval.
Regulatory Review and Public Consultation
In the event that the CANDU option is selected and has federal and provincial government agreement, prior to commitment and implementation, the proposed project would still have to meet all the requirements of applicable federal and provincial policies and legislation such as the Atomic Energy Control Act and the Canadian Environmental Assessment Act. Any project would be subject to the full assessment and licensing approvals of relevant federal and provincial safety, health and environment regulatory authorities. The approvals processes include provisions for public input.
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