Spent Fuel Interrogation Using Delayed Fast Neutron Spectrum at Missouri University of Science and Technology Reactor


Interrogation of nuclear fuel and Plutonium (Pu) and Uranium (U) discrimination was performed using Missouri University of Science and Technology Reactor (MSTR) fuel by non-destructive (NDA) method. Post-irradiated delayed fast neutron spectra were obtained for two pairs of burnt and fresh fuels. Burnup and 239Pu conversions were calculated based on neutron emission intensity ratios. After 100 kW high power runs, all fuel elements showed three distinct regions of neutron spectra; a distinct low energy peak followed by intermediate energy region without distinct peak but a wide hump, followed by a high energy peak with a long tail. At 10 kW low powers, intermediate energy hump and low energy peak seems to merge together while the high energy peak still remains distinct. Based on data from 10 kW power runs, the burnup values of F1 and F2 fuel elements were estimated to be 149 MWD/T and 196 MWD/T, respectively. 239Pu conversion since 1992 for low enriched (19.75%) fuel elements was calculated as 0.24 g for F1 and 0.32 g for F2. Results based on high power runs of 100 kW provided comparable burnup of 217 MWD/T for F2. However the results for F1 were approximately 10 times higher perhaps due to unique burnup history and consequently high poison buildup. These experimental burnup results compare well with the reactor burnup calculation as reported to the Nuclear Regulatory Commission (NRC).


Nuclear Engineering and Radiation Science


First author of this paper would like to express his gratitude for the financial support from the Turkish Ministry of National Education for providing support for a full doctoral program. Authors would also like to express their sincere appreciation for MSTR staff for providing support during data collection for this research and Dr. Xin Liu for offering the use of neutron measurement system.

Keywords and Phrases

Engineering education; Neutrons; Nuclear fuel elements; Well drilling; Burn up; Emission intensity ratio; Fast neutron spectrums; Fast neutrons; Intermediate energies; Intermediate energy region; Nuclear regulatory commission; Science and Technology; Fuels; Burnup credit; Delayed fast neutrons; Pu/U discrimination

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Article - Journal

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© 2015 Elsevier, All rights reserved.

Publication Date

01 Nov 2015