Excess reactivity optimization on High Temperature Gas Reactor (HTGR) design for remote area

Abstract East Nusa Tenggara (NTT) is an island that has an electrification ratio of 85.84%. Small power nuclear power plant could be applied in such a remote area, and High-Temperature Gas Reactor (HTGR) is one of the potential options. Based on data obtained from the Central Statistics Agency (BPS), an HTGR was designed. The purpose of the present study was to find the optimal excess reactivity for HTGR using the basic model of Japan’s HTTR (High-Temperature Engineering Test Reactor). The calculation was conducted using the Standard Reactor Analysis Code System (SRAC) with the Japanese Evaluated Nuclear Data Library (JENDL) 4.0 as the nuclear data library. Calculations for modified HTTR geometry and fuel configuration was performed and analyzed. As a result, for 1.6 times the HTTR geometry model, (7.00 - 8.75)% fissile enrichment with the addition of 0.065% B4C material is the best configuration to obtain the optimal excess reactivity. Meanwhile, for 1.5, 1.4 and 1.3 times HTTR geometry the best configuration values were (5.00 - 6.75)% fissile enrichment with 0.035% B4C, (6.00 - 7.75)% fissile enrichment with 0.045% B4C and (7.00 - 8.75)% fissile enrichment with 0.050% B4C, respectively.