Citation:
A.M. LaFleur, W.S. Charlton, H.O. Menlove, M. Swinhoe, “Development of Self-Interrogation Neutron Resonance Densitometry (SINRD) to Measure the 235U and 239Pu Content in a PWR 17×17 Spent Fuel Assembly”, Proceedings of 31st Annual Meeting of ESARDA, May 26-28, 2009, Vilnius, Lithuania.
Abstract:
The use of Self-Interrogation Neutron Resonance Densitometry (SINRD) to measure the 235U and 239Pu content in a PWR spent fuel assembly was investigated via Monte Carlo N-Particle eXtended transport code (MCNPX) simulations. The sensitivity of SINRD is based on using the same fissile materials in the fission chambers as are present in the fuel because the effect of resonance absorption lines in the transmitted flux is amplified by the corresponding (n,f) reaction peaks in fission chamber. These simulations utilize the 244Cm spontaneous fission neutrons to self-interrogate the fuel pins. The amount of resonance absorption of these neutrons in the fuel can be measured using 235U and 239Pu fission chambers placed adjacent to the assembly. We used ratios of different fission chambers to reduce the sensitivity of the measurements to extraneous material present in fuel. The development of SINRD to measure the fissile content in spent fuel is of great importance to the improvement of nuclear safeguards and material accountability. Future work includes the use of this technique to measure the fissile content in FBR spent fuel and heavy metal product from reprocessing methods.