[3O10-14] new type reactor development

[3O11] OTTO cycle Small Pebble Bed Reactor with Rock-like fuel elements

(4)Burnup performance in molten salt coolant

Hai Ho¹, ＊Toru Obara¹ (1.Tokyo Institute of Technology)

Keywords:pebble bed reactor, rock-like fuel, OTTO cycle, molten salt coolant, high burnup

In previous study, a 120 MW-th pebble bed high-temperature gas-cooled reactor (PBR) with rock-like oxide (ROX) fuel has been designed to improve the integrity of the spent fuel in geological disposal. However, the reactor power was low due to the small volumetric heat capacity of helium coolant. The molten salt coolant, with much higher volumetric heat capacity than that of helium coolant, is a solution to increase the reactor power of the PBR. Therefore, in this study the neutronic and criticality calculation were performed to show the feasibility of U-ROX fuel PBR with flibe coolant. The temperature reactivity coefficients were also investigated to ensure the negative temperature feedback of the PBR with flibe coolant.