B. Goddard, W.S. Charlton, C. Gariazzo, P. Peerani, “A Concept for Quantitative NDA MOX Measurements Using Only Neutron Radiation”, 52nd Annual Meeting of the Institute for Nuclear Materials Management (INMM), Palm Desert, CA, July 17-21, 2011.
There is a desire in the world to reduce the quantity of Pu in storage by burning it as mixed oxide (MOX) fuel in nuclear reactors. For safeguards reasons, the masses of both the 235U and Pu in MOX fuel must be quantified, preferably using non-destructive assay (NDA) techniques. Current NDA techniques require both gamma ray and neutron measurements to be performed. This research investigates the ability to quantify the 235U and Pu content of MOX fuel using only neutron measurements. This would reduce the amount of equipment needed and subsequently the cost required to conduct the measurement. This measurement technique is based on performing three different neutron measurements and analyzing their neutron multiplicity response. The first measurement is a passive measurement of a 252Cf standard to determine the detector efficiency (ε). The second measurement, in a passive configuration, will determine the effective plutonium-240 (240Pueff) content, self multiplication (M), and alpha-neutron reaction rate (α). The third measurement, in an active configuration using interrogation neutrons from an Am-Li alpha neutron source, will determine the effective plutonium-239 (239Pueff) content and 235U content. Simulated and measured results will illustrate the viability of this technique and its practical limitations.