Safeguards Approach Study for High Temperature Engineering Test Reactor (HTTR)

The High Temperature Engineering Test Reactor (HTTR) is a HTGR-type research reactor with thermal power of 30 MW, using low-enriched uranium. The enrichment is between 3 and 10 WI%. The fuel block consists of fuel rods and a hexagonal graphite block. The prinwy coolant is helium gas. The invento~ verification is difficult of the reactor core and spent fiel storage because they belong to “difiicult-to-access areas” due to the strong radiation. The safeguards approach for HITR cannot be found among the established ones for Research Reactor and Critical Assemblies(RRCAs). We have to work out a new specific safeguard approach that is appropriate for the HTTR. The difficulty in inventory verification of the core and spent fuel storage is overcome by introduction of the concept of spent fuel flow verification. The reduction in the safeguards efforts are expected by the spent fuel flow control in unattended modes and application of the dual C/S for the spent fhel storage.