Development of neutron spectrum analysis method to assess the content of fissile isotopes in SFA

Abstract

The paper presents the integrated neutron spectrum analysis as a potential method for estimating the contents of fissile isotopes in SFAs. Two method implementation variants are described: (1) measurement of SFA average transmission and (2) measurement of sample average transmission in the spectrum that has passed a SFA. The authors describe the dependences of SFA average transmission on its content of the required isotope obtained by means of two types of detectors: helium counter tube and fission chamber. Also, the authors propose a method to estimate SFA burn-up by means of the integrated NSA. In addition, SFA residence time influence on transmission is estimated.

Keywords

• Spent fuel
• Neutron spectrum analysis
• 235U and 239Pu content assessment
• Helium counter tube
• Fission chamber
• transmission
• Fuel assembly
• Residence time