ASSESSMENT OF GAMMA HEATING IN THE GRAPHITE-MODERATED MOLTEN SALT REACTOR TMSR-500 USING OPENMC SIMULATIONS Nurul K Fitriyani*, Rida S.N. Mahmudah, Azizul Khakim
*Physics departemant, faculty of mathematics and natural science (FMIPA) Yogyakarta State University, Sleman 55581, Indonesia
Research Center for Nuclear Reactor Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency (BRIN), Building No. 80 BJ Habibie Science and Technology Area, Setu, South Tangerang 15314, Indonesia.
Abstract
Ensuring the safety and efficiency of the TMSR-500 reactor, a Generation IV Molten Salt Reactor (MSR), is crucial for its planned development in Indonesia. This study evaluates gamma heating exposed to the graphite moderator, contributing to the main heat source in the graphite. The TMSR-500, an advancement of the Molten Salt Reactor Experiment (MSRE), utilizes molten salt fuel, is graphite-moderated, and operates at high temperatures. The effective moderation by graphite reduces neutron energy from fast to thermal levels, ensuring optimal fission sustainability and impacting gamma heating. OpenMC simulations were employed using the Python programming language and Monte Carlo methods to assess gamma heating with ENDF/B-VII.1 nuclear data and a particle count of one million. The simulations were conducted on The National Research and Innovation Agency^s computer facilities. The maximum gamma flux was observed at energies greater than 1 eV, with a measured value of 1.8096 x 10^(14) photons/cm^2 sec. The gamma heating in graphite was found to be 3.4917 W and the corresponding volumetric gamma heating was 9.1 x 10^(-3) W/cm^3. The results indicate that gamma heating in the TMSR-500 has a percentage of 2.0138 of the reactor^s total power, within the level of common knowledge.
