Effect of Reactor Fuel Enrichment on Gamma Heating of Irradiated Samples

Assessment of the gamma heating deposited on samples irradiated in material testing reactors is basic safety issue. The GHRRC (Gamma Heating in Research Reactor Cores) code developed in NCSR ¿Demokritos¿ is used here to estimate the relative importance of the mechanisms contributing to the total gamma heating of the irradiated material, for a core fuelled with Low (LEU) and with High Enrichment Uranium (HEU). The Greek Research Reactor core configuration with a 13% burnup has been assumed for the numerical experiments. The gamma heating of a Fe sample irradiated near the core center is examined. The heating components due to fission gammas, capture gammas and gamma dose build-up in the core are compared with respect to the fuel enrichment. Although individual components are found higher either in the LEU or in the HEU core, the total gamma heating is found comparable for the two fuel enrichments.