Plutonium fuel cycle

Civex A Diversion-Proof Plutonium Fuel Cycle," EPRI... 

Bell, J. T. In "Proceedings of the ANS Topical Meeting on the Plutonium Fuel Cycle", 1977 CONF-7705061. (c) Rofer-DePoorter,... 

Flowers, R. H., Johnson, K. D. B., Miles, J. H., and Webster, R. K., "Possible Long Term Options for the Fast Reactor Plutonium Fuel Cycle," Paper presented at the 5th Energy Technology Conf., Washington, D. C., 1978. 

Toth, L. M., Friedman, H. A., and Bell, J. T., "Photochemical Separation of Actinides in the Purex Process," Paper presented at the Plutonium Fuel Cycle Mtg., Bal Harbour, FL., 1977. 

Lloyd, M. H. "Chemical Behavior of Plutonium in LWR Fuel Reprocessing Solutions." Conference Plutonium Fuel Cycle Process, ANS National Topical Melting, Miami, Florida,... 

Fission energy can be obtained from uranium, using the uranium once-through option and the uranium-plutonium fuel cycle, and from thorium, by the thorium-uranium fuel cycle. Each fuel cycle offers a number of alternative routes with respect to reactor type, reprocessing, and waste handling. Although the uranium based cycles are described with special reference to light water reactors, the cycles also apply to the old uranium fueled gas cooled reactors. 

The heavy arrows in Fig. 21.1 indicate the steps in the nuclear fuel cycle pres dy used on a large commercial scale. The cycle stops at the spent fuel interim storage facility from here two alternative routes are available, one leading to the uranium-plutonium fuel cycle (reprocessing of the spent fuel elements, as described in the next section) and another leading to final storage of the unreprocessed spent fuel elements. The latter is referred to as the once-through fuel cycle (UOT) option. 

Problems relevant in the long-term are the radiotoxicity of the fuel and the long-term risk related to a final repository, which can be steered by an adequate choice of fuel cycle and reactor type. Moreover, it is possible to transmute very long-lived actinides and fission products into less toxic or stable nuclei by means of specific nuclear reactions. Following figure summarises these options for the back-end in the case of the uranium-plutonium fuel cycle. 

T. H. Pigford and K. P. Ang, The plutonium fuel cycles. Health Phys. 29(4), 451-468 (1975). P. SiLVENNOiNEN, Reactor Core Fuel Management, Pergamon Press, Oxford (1976). 

The MSR (see Fig. 2.7) embodies the very special feature of a liquid fuel. MSR concepts, which may be used as efficient burners of transuranic elements from spent LWR fuel, also have a breeding capability in any kind of neutron spectmm ranging from thermal (with a thorium fuel cycle) to fast (with a uranium—plutonium fuel cycle). Whether configured for burning or breeding, MSRs have considerable promise for the minimization of radiotoxic nuclear waste. 

Pebble bed and prismatic reactor are the two major design variants. Both are in use today. In either case, the basic fuel construction is the TRISO-coated particle fuel. Uranium, thorium, and plutonium fuel cycle options have been investigated and some have been operated in the reactors. Spent fuel may be direct disposed or recycled. The unique constmction and high bumup potential of the TRISO fuel enhances proliferation resistance. 

The recycle weapons fuel cycle rehes on the reservoir of SWUs and yellow cake equivalents represented by the fissile materials in decommissioned nuclear weapons. This variation impacts the prereactor portion of the fuel cycle. The post-reactor portion can be either classical or throwaway. Because the avadabihty of weapons-grade fissile material for use as an energy source is a relatively recent phenomenon, it has not been fully implemented. As of early 1995 the United States had purchased highly enriched uranium from Russia, and France had initiated a modification and expansion of the breeder program to use plutonium as the primary fuel (3). AH U.S. reactor manufacturers were working on designs to use weapons-grade plutonium as fuel. 

Plutonium. The plutonium nitrate product must be converted to MO fuel if it is to be recycled to lightwater reactors. Whether from a plutonium nitrate solution or a mixed U/Pu nitrate solution, the plutonium is typically precipitated as the oxalate and subsequendy calcined to the oxide for return to the fuel cycle (33). 

Pu. The Pu has seen appHcation as a long-Hved isotopic heat source. Plutonium-238 is most usehil in space programs, but is also of interest as part of a proliferation-resistant fuel cycle (2). 

Not all of the Pu-239 will fission during the fuel cycle in a nuclear reactor. Some of the plutonium will not experience neutron bombardment sufficient to cause fission. Other plutonium atoms will absorb one or more neutrons and become higher numbered isotopes of plutonium, such as Pu-240, Pu-241, etc. Plutonium comprises just over 1 percent of nuclear reactor spent fuel—the fuel removed from the... 

The plutonium-uranium fuel cycle has particular advantages in fast spectrum... 

If nonproliferation considerations have not led to official opposition to nuclear power, their effect on fuel cycle policy has been profound. Although, its rhetoric and many of its implementating actions have been more restrained, the Clinton Administration has, in principle, adopted the Carter policy of opposition to reprocessing and plutonium recycle, hr at least one important area, however, it has inexplicably out-Cartered earlier policy by terminating work on proliferation-resistant firel cycles that involve recycle of still highly radioactive plutonium. 

The spent firel issue is central to long-term fuel cycle policy, not simply because large volumes are threatening to clog the arteries of the nuclear power industry but because spent fuel is the repository of most of the worid s plutonium, some 1000 tons at present, and is already dispersed among the 30-odd countries in which nuclear power plants are located. The indefinite accumulation of these dispersed inventories has proliferation implications that are at least comparable in their gravity to the surplus weapons plutonium inventories in Russia... 

While the goal of bringing plutonium production and consumption into balance is a long term one, research and development on proliferation-resistant fuel cycles should be taking place at present. International cooperation ofthe appropriate countries in this R D is also essential. Failure to pursue a suitable R D effort and international cooperation is virtually certain to result in the adoption ofthe most proliferation-prone fuel cycle when the plutonium breeder is deployed in the next century. 

Alternative reactor types are possible for the VHTR. China s HTR-10 [35] and South Africa s pebble bed modular reactor (PBMR) [41] adopted major elements of pebble bed reactor design including fuel element from the past German experience. The fuel cycles might be thorium- or plutonium-based or potentially use mixed oxide (MOX) fuel. 

Nuclear fuel recycling allows more efficient nuclear fuel usage and less buildup of nuclear waste. Nuclear power reactors are designed to minimize plutonium build up and much of the plutonium that is produced inside the reactor is used during an ordinary fuel cycle. 

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