MEASUREMENT OF GAMMA-RAY SPECTRA AND HEATING RATES IN IRON AND STAINLESS-STEEL SHIELDS BOMBARDED BY DEUTERIUM-TRITIUM NEUTRONS AND VALIDATION OF SECONDARY-GAMMA-RAY DATA IN EVALUATED NUCLEAR-DATA LIBRARIES

Benchmark experiments for the validation of secondary-gamma-ray data a re conducted for iron and Type 316 stainless steel (SS316) shield asse mblies bombarded by deuterium-tritium neutrons. Gamma-ray spectra and heating rates for both threshold and capture gamma rays are measured. With the present experimental data for gamma rays, a set of benchmark data for iron and SS316, including neutron energy spectra in entire en ergies and various dosimetry reaction rates, is completed for the firs t time. Secondary-gamma-ray data in JENDL-3.1, JENDL-3.2, JENDL-Fusion File, and FENDL/E-1.0 are tested by benchmark calculation of the expe riments. As a result, larger gamma-ray-production cross sections for t hreshold reactions in JENDL-3.1 and JENDL-3.2 and an inconsistent ener gy balance of the (n,gamma) reactions in JENDL-3.1 are found. From the viewpoint effusion engineering, the first priority in evaluating seco ndary-gamma-ray data should be conserving the energy balance. A rigid energy balance in both the JENDL Fusion File and FENDL/E-1.0 is confir med for both threshold and capture gamma rays. The JENDL Fusion File a nd FENDL/E-1.0 provide the highly accurate secondary-gamma-ray data fo r iron and SS316 needed for fusion reactor nuclear design.