E.R. Merz – författare

MOX fuel, a mixture of weapon-grade plutonium and natural or depleted uranium, may be used to deplete a portion of the world's surplus of weapon-grade plutonium. A number of reactors currently operate in Europe with one-third MOX cores, and others are scheduled to begin using MOX fuels in both Europe and Japan in the near future. While Russia has laboratory-scale MOX fabrication facilities, the technology remains under study. No fuels containing plutonium are used in the US The 25 presentations in this book give an overview of MOX technology.

In the immediate term, plutonium recovered from dismantled nuclear warheads will have to be stored securely, under international safeguards where possible. One of the principal alternatives for the disposition of this plutonium is to blend it with high-level waste as it is vitrified for final disposal in a geologic repository. The high radioactivity of the resulting product provides self-shielding and ensures that the Pu cannot be separated without the development of highly sophisticated technology. This third NATO ARW on the disposal of weapons-grade plutonium discusses the non-reactor disposition option, presenting a thorough evaluation of the pros and cons. In broad terms, the workshop presents an exchange of information on waste vitrification, including technical feasibility as well as the necessary stringent safeguards. It discusses the different approaches to the optimum techniques and credible alternatives for immobilizing transuranics and fission products for disposal. It introduces new disposal techniques, in particular matrix immobilization followed by deep borehole disposal.It assesses the implications of safeguarding requirements and identifies common areas in which defined research tasks can be initiated in co-operative partnership.

MOX fuel, a mixture of weapon-grade plutonium and natural or depleted uranium, may be used to deplete a portion of the world's surplus of weapon-grade plutonium. A number of reactors currently operate in Europe with one-third MOX cores, and others are scheduled to begin using MOX fuels in both Europe and Japan in the near future. While Russia has laboratory-scale MOX fabrication facilities, the technology remains under study. No fuels containing plutonium are used in the U.S. The 25 presentations in this book give an impressive overview of MOX technology. The following issues are covered: an up to date report on the disposition of ex-weapons Pu in Russia; an analysis of safety features of MOX fuel configurations of different reactor concepts and their operating and control measures; an exchange of information on the status of MOX utilisation in existing power plants, the fabrication technology of various MOX fuels and their behaviour in practice; a discussion of the typical national approaches by Russia and the western countries to the utilisation of Pu as MOX fuel; an introduction to new ideas, enhancing the disposition option of MOX fuel exploitation and destruction in existing and future advanced reactor systems; and the identification of common research areas where defined tasks can be initiated in cooperative partnership.

A survey of recent developments in the field of plutonium disposal by the application of advanced nuclear systems, both critical and subcritical. Current national R&D plans are summarized. The actinide-fuelled critical reactors are associated with control problems, since they tend to have a small delayed neutron fraction coupled with a small Doppler effect and a positive void coefficient. Current thinking is turning to accelerator-driven subcritical systems for the transmutation of actinides. The book''s conclusion is that the various systems proposed are technically feasible, even though not yet technically mature. The book presents a unique summary and evaluation of all relevant possibilities for burning surplus plutonium, presented by experts from a variety of different disciplines and interests, including the defence establishment. The obvious issue - the non-proliferation of nuclear weapons - is vital, but the matter represents a complex technological challenge that also requires an assessment in economic terms.

A survey of recent developments in the field of plutonium disposal by the application of advanced nuclear systems, both critical and subcritical. Current national R&D plans are summarized. The actinide-fuelled critical reactors are associated with control problems, since they tend to have a small delayed neutron fraction coupled with a small Doppler effect and a positive void coefficient. Current thinking is turning to accelerator-driven subcritical systems for the transmutation of actinides. The book's conclusion is that the various systems proposed are technically feasible, even though not yet technically mature. The book presents a unique summary and evaluation of all relevant possibilities for burning surplus plutonium, presented by experts from a variety of different disciplines and interests, including the defence establishment. The obvious issue - the non-proliferation of nuclear weapons - is vital, but the matter represents a complex technological challenge that also requires an assessment in economic terms.

This NATO Advanced Research Workshop on Disposal of Weapons Plutonium is a follow-up event to two preceding workshops, each dealing with a special subject within the overall disarmament issue: "Disposition of Weapon Plutonium", sponsored by the NATO Science Committee. The first workshop of this series was held at the Royal Institute of International Affairs in London on 24-25 January 1994, entitled "Managing the Plutonium Surplus, Applications, and Options". Its over­ all goal was to clarify the current situation with respect to pluto­ nium characteristics and availability, the technical options for use or disposal, and their main technical, environmental, and economic constraints. In the immediate term, plutonium recovered from dismantled nuclear warheads will have to be stored securely, and under international safeguards if possible. In the intermediate term, the principal alter­ natives for disposition of this plutonium are: irradiation in mixed­ oxide (MOX) fuel assemblies in existing commercial light-water reac­ tors or in specially adapted light-water reactors capable of operation with full cores of MOX fuel .and irradiation in future fast reactors. Another option is to blend plutonium with high-level waste as it is vitrified for final disposal in a geologic repository. In both cases, the high radioactivity of the resulting products provides "self­ shielding" and prevents separation of plutonium without already­ developed and available sophisticated technology. The so-called "spent fuel standard" as an effective protection barrier is - quired in either case.