Use of a SLOWPOKE-2 Reactor for Nuclear Forensics Applications

Abstract

A low enriched uranium SLOWPOKE-2 reactor is used as a neutron interrogation source in support of the identification and characterization of Special Nuclear Materials (SNM) at the Royal Military College of Canada (RMCC). Small amounts of fissile uranium and plutonium are sent into a SLOWPOKE-2 irradiation site before their transport to RMCC’s delayed neutron and gamma counting (DNGC) system. The counting arrangement of the DNGC consists of an array of six 3He and a high purity germanium detector. These detectors record the delayed neutron and photon emissions as a function of count time, to verify MCNP6 simulations of delayed particle emissions, and to detect and quantify trace amounts of fissile content. This paper discusses MCNP analyses done in preparation for an upcoming nuclear forensics exercise in the fall of 2014. MCNP6 simulations of the DNGC system focussed on the identification of characteristic gamma lines from prominent fission products. The relative intensities of these gamma lines are dependent on the SNM content in the sample. Gamma line pairs useful for SNM identification in RMCC’s DNGC system are presented.