Monte Carlo Simulation of Response of Beta-Delayed Neutron Inspection System for Fuel Cladding Damage

Abstract This work was aimed to design one novel device to monitor β-delayed neutron in the circuit coolant water. The response of β-delayed neutron inspection system was primarily simulated by PHITS Monte Carlo code including the pulse height spectrum, detection efficiency and time spectrum of neutron counters. The detection efficiencies (from 1 keV to 1 MeV) of two neutron monitors were respectively displayed as about 50% (12 He-3 counters) and about 30% (108 10B-coated counters). The beta monitor was designed as array of thin-slice plastic scintillators immersed in water to attain as large detection efficiency as possible. The simulated detection efficiency for beta particles (energy higher than 1 MeV) was more than 34%.