Application of the pyrochemical process to recycle of actinides from LWR spent fuel

Abstract

The Integral Fast Reactor (IFR) process includes recycle of all of the actinides contained in spent IFR fuel, and thus reduces waste disposal challenges. Pyrochemical processes also appears suitable for recovering and recycling actinides from spent fuels from light water cooled reactors (LWRs). Following surveys of many pyrochemical processes, two candidates have been selected for further development. A calcium/salt transport process operating at 800 to 850°C appears to recover the transuranic (TRU) elements efficiently. The oxide fuel is reduced to metal using calcium reductant. Salt extraction and transport are used to effect a suitable separation of transuranics from the excess uranium and the bulk of the fission products. The metallic TRU product is then used as feedstock for casting fast reactor fuel pins. An alternate, and currently preferred, process involves a lithium reductant operating at about 650°C. The electrorefining step used to separate the TRU product from the bulk excess uranium is precisely the one already developed for the IFR recycle. Basic laboratory work shows that either process would be feasible and engineering-scale experiments are being prepared.