Year
2014
Abstract
Pyroprocessing is a forefront technology used to recycle spent nuclear fuel (SNF) without completely separating the uranium a nd plutonium, and therefore is considered by some to be more resistant to nuclear proliferation. Because there is no dissolution step, there is no equivalent of an input accountancy tank and input accountancy must be accomplished by nondestructive assay ( NDA ) of SNF rods or assemblies. Since pyroprocessing exists only on a pilot scale, the International Atomic Energy Agency (IAEA) has not yet developed an approach for safeguarding planned facilities. A new approach has been identified for back - end advanced fuel cycle safeguards via pyrochemical processing. Oak Ridge National Laboratory is home to the Hybrid K - Edge/X - Ray Fluorescence Densitometer (HKED) system, which may be used for research and development. The HKED system is an established and highly accur ate NDA instrument used to support safeguards verification measurements during reprocessing activities for nuclear material accountancy by the IAEA . Using a combination of K - edge densitometry and X - ray fluorescence techniques, the HKED quantifies input and product heavy metal actinide elements, such as uranium and plutonium in reprocessing streams. Capabilities and limitations are discussed herein for extending the HKED system beyond solutions for aqueous systems with uranium and plutonium ratios of 100:1 t o include additional minor actinides from pyroprocessing (neptunium/americium) in spent fuel and where uranium and plutonium ratios approach 1:1.