Breeder reactor fuels

A variation of the classical fuel cycle is the breeder cycle. Special breeder reactors are used to convert fertile isotopes iato fissile isotopes, which creates more fuel than is burned (see Nuclear reactors, reactor types). There are two viable breeder cycles U/ Pu, and Th/ U. The thorium fuels were, however, not ia use as of 1995. A breeder economy implies the existence of both breeder reactors that generate and nonbreeder reactors that consume the fissile material. The breeder reactor fuel cycle has been partially implemented ia France and the U.K. 

M. Levenson, J. V. C. Trice, and W. J. Mecham, Comparative Cost Study of the Processing of Oxide, Carbide, and MetalFast Breeder Reactor Fuels by Aqueous, Uolatility andPyrochemicalMethods, ANL-7137, Argonne National Laboratory, Argonne, lU., 1966. 

FAME FAO FBR FC FCV FFV FOB FPFC Fatty acid methyl ester Food and Agriculture Organization of the United Nations Fast-breeder reactor Fuel cell Fuel-cell vehicle Flexible-fuel vehicle Free on board Fuel-processor fuel cell... 

I have devoted more space to explaining the dangers of nuclear power than to the consequences of using fossil fuels, because while the consequences of carbon emission are well understood, the inexhaustible nature of thermal power and the implications of terrorists using breeder reactor fuel for military purposes are largely unknown. 

When more them one solute is involved in the consideration of the process design, the situation becomes much more complex since the extraction behaviours of the different solutes will usually be interdependent. In the case of irradiated thermal reactor fuels the solvent extraction process will be dealing with uranium containing up to ca. 4% of fission products and other actinides. These will have only a minor effect on uranium distribution so that a single-solute model may be adequate for process design. However, in some cases nitric acid extraction may compete with U02 extraction and a two-solute model may be needed. In the case of breeder reactor fuels the uranium may contain perhaps 20% of plutonium or thorium. Neptunium or protactinium levels in such fuels may also not be negligible and, under these circumstances, the single-solute... 

Nonstoichiometry diminishes the already low thermal conductivity, lowers the melting point and strength, increases creep and fission product migration and release, and alters irradiation behavior. The increase in oxygen activity with burnup can be significant in leading rods in light-water reactors (5%burnup) and in fast breeder reactor fuels (10% burnup). 

Fast breeder reactor fuel rods consist of stainless-steel-clad mixed oxide (U,Pu)02 fuel however, more stable alloys for cladding and in-core structural materials, with resistance to swelling and embrittlement under fast neutron irradiation, and more efficient fuels (carbide see 17.3.12.1.2) or nitride (see 17.3.12.3)] are needed h The mechanical, metallurgical, and chemical processes in fuel element irradiation are depicted in Figure 1. Figure 2 shows the PFR (U.K.) fast breeder fuel element, and Figures 3 and 4 illustrate the Fast Flux Test Facility (FFTF) fuel system. 

E.C. Norman, ed., Fast Breeder Reactor Fuel Performance, Proc. Int. Conf, March 5-8, 1979, Monterey, CA American Nuclear Society, La Grange, IL, 1979. 

---