Neutron Damage in SiC Semiconductor Radiation Detectors in the GT-MHR

Abstract

Abstract As a part of a U.S. Department of Energy Nuclear Engineering Research Initiative (NERI) project, we are evaluating the potential for using silicon carbide (SiC) semiconductor radiation detectors, operating in the pulse mode, as power monitors for gas turbine modular helium reactor (GT-MHR) [1]. Locations for the power monitors will be selected considering acceptable detector count rates and lifetimes. We have characterized the radiation environment at various locations in the GT-MHR, where detectors may be placed, in terms of the 1 MeV equivalent neutron flux in SiC (φeq,1 MeV, SiCTotal). Also, we have characterized the radiation field in beam part 1 (BP1) of the Ohio State University Research Reactor (OSURR) in these same terms, with the intent of correlating observed degradation of the SiC detectors in the OSURR to the degradation that can be expected for various detector locations in the GT-MHR. Comparing φeq,1 MeV, SiCTotal for the GT-MHR and for the OSURR, we conclude that SiC devices cannot be adequately tested in the characterization vessel in OSURR BP1 for the radiation damage that would be incurred over a refueling cycle for detectors placed in-core. Also, we note that the radiation environment in the OSURR BP1 is harder than the radiation environment in the GT-MHR.