High Count Rate, High Temperature Neutron/Gamma Detector for Advanced Reactors

One of the goals of Department of Energy’s Material Protection, Accounting and Control Technologies Campaign is to develop nuclear material accounting methods for next generation, advanced fuel cycles such as Molten Salt Reactors. There are several challenges for nuclear material accounting of Molten Salt Reactors, for example, the high temperature and high dose rates, at which the measurements need to be performed. The goal of the proposed research is to develop high-count-rate, high temperature neutron/gamma-ray detectors that can operate in a Molten Salt Reactor environment. We propose to develop a new high performance detector that can handle high count rates and high temperatures in advanced fuel cycles by designing and implementing an integrated readout electronics system that performs pulse shape discrimination to separate gamma and neutron events. We will utilize dual-mode sensors developed at Radiation Monitoring Devices, Inc. that provide excellent gamma spectroscopic capabilities and high sensitivity to neutrons. In Phase I of the proposed research, we will demonstrate the feasibility of such a detector by assembling a proof-of-principle system with one of the new fast, high sensitivity scintillator materials developed at Radiation Monitoring Devices, Inc. We will study the effect of the event rate and temperature on the gamma-ray spectral energy resolution and gamma/neutron discrimination for dual mode scintillation materials. At the end of Phase I, we will make a decision on the type of scintillator that will be pursued in Phase II. A radiation detection system capable of simultaneous detection of gamma-rays and neutrons at high count rates and temperatures, with good gamma-ray resolution and neutron efficiency will easily find its application in nuclear power plant management, well logging, nuclear plant decommissioning, dosimetry, homeland security, and nuclear physics.