Neutron Resonance Transmission Analysis of Reactor Spent Fuel Assemblies

Uncertainty assessment of neutron resonance transmission analysis using the linear absorption model

“…We consider boron and iron as representative impurities. As the densities of 56 Fe and nat B, 7.87 and 2.34 g/cm 3 were used. Although fission products and minor actinides are also expected to exist in debris samples, these impurities were neglected in the current estimation since they will not severely disturb the measurement of the densities of U and Pu by NRTA [3].…”

“…In a previous measurement of spent fuel [3], atomic densities of nuclear materials were determined with the uncertainty of 1%-4%. The parameters of that measurement are the sample thickness of 2.5 cm, the average neutron production rate of about 10 13 n/s, the repetition rate of 360 pulse/s, and the measurement time of 20 min.…”

“…The * Corresponding author. Email: kitatani.fumito@jaea.go.jp NRD is a combined technique of neutron resonance transmission analysis (NRTA) [3] and neutron resonance capture analysis (NRCA) [4,5].…”

Further Evaluation of the Neutron Resonance Transmission Analysis (NRTA) Technique for Assaying Plutonium in Spent Fuel

“…[3][4][5] The technique uses a pulsed accelerator to produce an intense, short pulse of neutrons. These neutrons, traveling at different speeds according to their energy in a time-of-flight (TOF) configuration, are used to interrogate a spent fuel assembly.…”

“…Neutron detection is performed using a high-rate sensor, such as a lithiated-glass scintillation detector. [4][5][6] Results are read from the detector as count rate versus time, with faster (higher-energy) neutrons arriving first and slower (lower-energy) neutrons arriving later. The low-energy elastic scattering and absorption resonances of plutonium and other isotopes modulate the transmitted neutron spectrum.…”