Plutonium recycling and the problem of nuclear proliferation

A typical 1-gigawatt light water reactor (LWR), the dominant commercial power reactor type today, operating at 70% capacity factor, generates approximately 250 kilograms of plutonium annually. This plutonium, which is produced in the reactor through neutron capture by uranium-238, is then discharged from the reactor along with the other constituents of the spent fuel. About 70% of the plutonium, or 175 kilograms, consists of fissile (odd-numbered) plutonium isotopes. As long as the plutonium discharged from the reactor is left intermixed with the highly radioactive fission products also contained in the spent fuel, it cannot readily be used for power or for weapons. However, upon chemical separation from the radioactive fission products and other components of the spent reactor fuel, the plutonium produced each year in a gigawatt reactor could be used, either in recycled fuel (to replace about 175 kilograms of U-235 in a power reactor) or to provide the fissile material for more than 25 nuclear warheads. Commercial separation of plutonium and the introduction of nuclear fuel cycles using recycled plutonium, which are now impending in several countries, force one to balance the probable increased risks of nuclear proliferation due to these activities against various economic and other motives that have been forwarded in their defense. The authors undertake an assessment of this balancing in this article