American Nuclear Society

Home / Publications / Journals / Nuclear Technology / Volume 189 / Number 1

Implications of Plutonium Isotopic Separation on Closed Fuel Cycles and Repository Design

Charles Forsberg

Nuclear Technology / Volume 189 / Number 1 / January 2015 / Pages 63-70

Technical Paper / Fuel Cycle and Management /

Updated:December 22, 2014

Advances in laser enrichment may enable relatively low-cost plutonium isotopic separation creating a new unexplored dimension in fuel cycle options. This may have large impacts on light water reactor (LWR) closed fuel cycles and waste management. If 240Pu is removed before recycling plutonium as mixed-oxide (MOX) fuel, it would dramatically reduce the buildup of higher plutonium isotopes, americium, and curium. Plutonium-240 is a fertile material and thus can be replaced by 238U. Eliminating the higher plutonium isotopes in MOX fuel increases the Doppler feedback, simplifies reactor control, and allows infinite recycle of MOX plutonium in LWRs. Reducing production of 241Pu by removal of 240Pu reduces production of 241Am—the primary heat generator in spent nuclear fuel after several decades. Reducing heat-generating 241Am would reduce repository size, cost, and waste toxicity. Avoiding 241Am avoids its decay product 237Np, a nuclide that partly controls long-term oxidizing repository performance. The 240Pu could be added to the high-level waste for disposal. Some of these benefits also apply to plutonium recycled into fast reactors. However, the benefits are fewer because in a fast neutron spectrum, 240Pu is both a fissile material and a fertile material. There would be incentives to separate 242Pu and dispose of it as a waste.

Questions or comments about the site? Contact the ANS Webmaster.