Estimation of routine discharge of radionuclides on power reactor experimental RDE

Experimental power reactor (RDE), which is planned to be constructed by BATAN, is a kind of High Temperature Gas Cooled Reactor (HTGR) with 10 MWth power. HTGR is a helium gas-cooled reactor with TRISO-coated fuel that is able to confine fission products to be remained in the core. To ensure the safety for workers and public surroundings of the RDE site and to meet the regulatory body requirements for construction and operation, research is needed for environmental radiation in normal and abnormal condition. This study is focused on normal operating condition, while for the accident condition study will be carried out after the final design has been completed. Estimation of radiology in the environment involves the source term released into the environment under routine operation condition. The purpose of this study is to estimate the source terms released into the environment based on postulation of normal or routine operation of the RDE-10 MWth. The research approach starts with an assumption that there are defects and impurities in the TRISO fuel because of limitations during the fabrication. Mechanisms of fission products release from the fuel to the environment were created based on the safety features design of RDE. Radionuclides inventories in the reactor were calculated by the use of ORIGEN-2 whose library has been modified for HTGR type, while assumptions on TRISO fuel defects and release fraction for each compartment of the RDE safety systems are defined by a reference parameter. The results show that the important source terms of RDE are group of noble gases (Kr and Xe), halogen (I), Sr, Cs, H-3, and Ag. Activities of RDE source terms for routine operations have no significant difference with the HTR-10 source terms with the same power. (author)