Management and Disposition of Excess Weapons Plutonium Reactor-Related Options (1995) / Chapter Skim
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Chapter 7: Conclusions and Recommendations
Chapter 7: Conclusions and Recommendations
Pages 397-418
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From page 397... ...
rendering the plutonium resistant to diversion or theft by immobilizing it in waste forms similar to those contemplated for disposal of high-level wastes originating in nuclear reactors. This work has been motivated by the direct and indirect security dangers that would be posed by long continuation of the status quo in management of the increasing stocks of surplus plutonium from dismantled nuclear weapons, which consists of guarded and monitored storage of plutonium pits (the nuclear-explosive cores of the weapons)
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From page 398... ...
new reactors and/or fuels designed specifically for plutonium disposition, or for plutonium disposition in combination with tritium production. With respect to the end-points of reactor options for plutonium disposition, there is a continuous spectrum of possibilities in terms of residual plutonium quantity, isotopic composition, and quantity of accompanying fission products, but it is useful to distinguish three general classes of outcomes with somewhat different purposes, as follows: (i)
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From page 399... ...
(This way of doing so, unlike the reactor spent fuel approach, would not change the isotopic characteristics of the plutonium.) Vitrification options without fission products would offer quicker, easier processing at the cost of lower barriers to reuse in weapons; in that sense these options are analogous to the "spiking" variants of the reactor options.
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From page 400... ...
In the case of immobilization without fission products as a preliminary step, it can be questioned whether the temporary barriers added in this way, compared to storage as pits, are sufficient to offset the security risks and economic costs of the extra handling and processing steps involved. Acceptance of the "spent fuel standard" also effectively removes the "elimination" options from consideration as the primary disposition approach for the decades immediately ahead, although these options deserve continued study for their possible role in reducing the security hazards of all plutonium military and civilian in the longer term.
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From page 401... ...
We judge the direct and indirect security risks of such delay to be unacceptable. It makes far more sense to use one of the current-reactor/spent-fi~el options or immobilization with fission products to bring the surplus WTu relatively quickly to a level of protection comparable to that of plutonium in commercial spent fuel and then consider, in the light of evolving technological capabilities and evolving conceptions of the nuclear-energy future, how the residual security risks of all of the plutonium at the spent fuel standard, military and civilian alike, might be subsequently reduced.
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From page 402... ...
The limiting ingredients on the timing of the current-reactor/spent-fuel approach in the United States would be providing the needed MOX fuel fabrication capacity (no such capacity is currently operational in the United States) and obtaining the necessary approvals and licenses (use of MOX fuel in U.S.
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From page 403... ...
Given a timely decision to proceed with this option, it should be possible for the WNP reactor or reactors to begin loading MOX fuel in 2002, consistent with the schedule assumed for fuel fabrication at the FMEF. We have estimated the incremental costs of this option (net present value at start of reactor operation, 1992 dollars)
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From page 404... ...
LWRs, the pacing elements of a plutonium disposition scheme based on existing CANDU reactors would be provision of the needed MOX fuel fabrication capacity and obtaining the needed permissions and licenses for burning such fuel. Canada has no MOX filet fabrication capacity; fabricating MOX fuel for CANDUs at the FMEF is technically feasible and would be the most expeditious approach.
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From page 405... ...
This approach would require MOX fuel fabrication capacity substantially larger than could be readily provided at the FMEF facility, however. Currently operating commercial reactors in Russia and Ukraine also have the technical capacity to implement the "spent fuel" option in a timely way for a nominal 50 tons of surplus WPu from the stockpile of the fonder Soviet Union.
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From page 406... ...
The current rate of loading new fuel into naval reactors is essentially zero, moreover, meaning that the capacity for WPu 4 Under a scheme put forward by the Natural Resources Defense Council, for example, money from MOX-burning electric utilities that would have been paid, under existing reprocessing contracts, for reprocessed civilian plutonium in MOX fuel would instead be divided between paying a fair rate of return to the investors in commercial reprocessing plants that would not be operated and paying for WPu that would be processed into MOX.
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From page 407... ...
ADVANCED REACTORS AND SPECIALTY FUELS If the "spent fuel standard" is adopted, there is no need to develop and deploy an advanced-reactor type or nonfertile fuel type to achieve that aim. As indicated above, the numbers and characteristics of existing reactor types, using ordinary MOX fuels, are more than adequate to carry out the spent final option, and the limitation on the reactor-spiking option is fuel fabrication capacity, not inadequacies in the numbers or characteristics of reactors or the characteristics of fuels.
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From page 408... ...
Even given an early decision to use this option, we do not think the start of plutonium fuel loading into MlITGRs could occur before 2013 (Table 6-21. We estimate the cost of this option at $3,900 ~ $2,700 million if the reactor and its fuel fabrication plant do not pay property taxes and insurance and $5,800 ~ $3,200 million if they do (present value of net cost stream, after subtracting electricity revenues, in 1992 dollars as of start of reactor operation)
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From page 409... ...
, as well as monetary costs, in choosing the advanced reactors over currently operating types for this mission. Concerning the possible use of advanced reactors and/or advanced fuels to pursue the elimination of the WPu, which as noted above might eventually be deemed attractive as a step to follow the transformation to the spent fuel standard and to be applied to plutonium of civilian as well as military origin.
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From page 410... ...
IMMOBILIZATION OPTIONS We believe that WPu immobilization by vitrification in borosilicate glass represents a feasible technology that could meet the spent fuel standard, could be available in the relatively near future (within about a decade hence) , and could potentially immobilize all of the nominal 50 tons of U.S.
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From page 411... ...
A waste-vitrification facility with a nominal output of 1 ton of glass per day has been in operation at the Chelyabinsk-65 site in Russia since 1987. The phosphate glass composition employed at this facility appears to be both less durable and less resistant to recriticality if plutonium is embedded in it than is the borosilicate glass planned for U.S.
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From page 412... ...
A number of waste forms other than borosilicate glass have been proposed by various groups for consideration as alternatives for the immobilization of surplus WPu in ways that would, it is argued, meet the spent fuel standard. Besides the phosphate glass mentioned above, these candidates include synthetic rock ("synroc")
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From page 413... ...
With respect to security of the final plutonium forms, the current-reactor options obviously meet the spent fuel standard, and we judge that the vitrification-with-wastes option meets this standard also. The plutonium in the spent fuel assembly would be of lower isotopic quality for weapon purposes than the still weapons-grade plutonium in the glass log, but since nuclear weapons could be made even with the spent fuel plutonium this difference is not decisive.
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From page 414... ...
Although the central estimates in all cases considered correspond to net costs, our judgmental 70-percent confidence intervals include a possibility of profits from WPu disposition for the case in which currently mothballed, partly completed PWRs are completed for the purpose of plutonium disposition and use MOX fuel from FMEF, and for cases when new, evolutionary LWRs are ~ For example, a large glass log of the type expected to be produced at Savannah River's DWPF would contain 1,700 kg of glass in a 450 kg steel jacket; at 1.3-percent WPu in glass, it would hold 22 kg of plutonium; and, at the expected defense HEW content of 20 percent by weight, it would produce a gamma-ray dose rate of 2,600 rem/in at the surface of the container 30 years after the log was produced. By comparison, a MOX fuel assembly from a Westinghouse pressurized-water reactor would have a mass of about 660 kg, would contain about 18 kg of plutonium after irradiation to 40 MWd/kgHM (assuming initial WPu content of 4.0 percent of heavy metal)
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From page 415... ...
(Given such prices and the same financial assumptions, however, a higher profit would be available from a program that completed reactors or built new ones from scratch and used them to generate electricity using LEU rather than MOX fuel, without addressing the problem of plutonium disposition.) The range of $0.5-$5 billion (1992 dollars~covering the best estimates of net present value, at reactor or melter startup, of most of the options considered-corresponds to $10,000 to $100,000 per kilogram of WPu, or $40,000 to $600,000 for a nominal "bomb's worth" of 4~ kg.
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From page 416... ...
Vitrified waste logs, with or without plutonium, will need to be stored in engineered facilities until a geologic repository is ready to receive them; and plutonium-containing spent fuel from nuclear-reactor operations, whether WPu has been incorporated in some of it or not, will need to be stored at reactor sites or at other commercial spent fuel storage facilities until a repository is ready. RECOMMENDATIONS Two options have emerged from our investigations as the most promising ones for the disposition of surplus WPu: the use of LWRs or CANDU reactors, employing MOX fuel in a once-through mode, to embed the WPu in spent fuel that would be emplaced eventually in a geologic repository (together with the larger quantity of such spent fuel that will exist in any case from ordinary nuclear electricity generation)
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From page 417... ...
to manage pursuit of both options in parallel. In connection with the current-reactor/spent-fuel option, work should be started to seek out specific reactors and MOX fabrication options that would minimize multiple plutonium transportation steps so as to reduce this aspect of security risk, to identify locations that are most amenable to public acceptance, and to ascertain the willingness and conditions of the plant owners to participate.
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From page 418... ...
The panel recommends that the United States immediately initiate joint project-oriented activities with Russia covering both the MOX and the vitrification options. Studies of a follow-on nature should continue on the longer-range questions of whether and how the residual security risks of weapon and other plutonium should eventually be reduced beyond the spent fuel standard.
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