PNNL

Abstract

Expanded low-carbon baseload power production through the use of nuclear fission can be enabled by recycling long-lived actinide isotopes within the nuclear fuel cycle. This approach provides the benefits of a) more complete utilization of the energy potential of mined uranium, b) reduced footprint of nuclear geological repositories, and c) reduction in the radiotoxicity decay time for the disposed waste from one hundred thousand years to a few hundred years. A key step in achieving this goal is the separation of long-lived isotopes of americium and curium for recycle into fast reactors. To achieve this goal, a novel process was successfully demonstrated on a lab scale using a bank of 1.25-cm centrifugal contactors, fabricated by additive manufacturing, and a simulant containing the major fission products. Am and Cm were separated from the lanthanides with over 99.9% completion. The sum of the impurities of the Am/Cm product stream was found to be 3.2.10-3 g/L. The process performance was successfully validated using a genuine high burnup used nuclear fuel raffinate in a batch regime. Separation factors of nearly 100 for 154Eu over 241Am and were achieved. All these results indicate the process scalability to engineering scale.