A preliminary neutronic evaluation of the high temperature nuclear reactor (HTTR) using reprocessed fuel

• The HTTR was simulated using reprocessed fuels spiked with thorium and depleted uranium.
• The effective neutron multiplication factor and the nuclear fuel evolution during the burn-up were analyzed.
• The results indicated that reprocessed fuels can be used in the HTTR.

The High Temperature Engineering Test Reactor (HTTR), a 30 MWth, graphite-moderated, helium-cooled reactor constructed by the Japanese government was simulated using reprocessed fuel obtained by UREX+ and spiked with thorium-232 and with depleted uranium. The effective neutron multiplication factor and the nuclear fuel evolution during the burn-up were analyzed. This study was performed using the ORNL SCALE 6.0 code, with CSAS6 and TRITON6 control modules. The results show in a preliminary way that the burn-up of reprocessed fuels in the HTTR core is possible, although the fissile material quantities should be increased while compared with the enrichments of the standard fuel.