Preliminary accident analysis for a conceptual design of a 10 MW multi-purpose research reactor

Park, C.; Tanimoto, Masataka ; Imaizumi, Tomomi; Miyauchi, Masaru; Ito, Masayasu ; Kaminaga, Masanori  

Preliminary accident analysis has been carried out for a LOFA (Loss of Flow Accident) and RIAs (Reactivity Insertion Accidents) of the conceptual 10 MW MRR (multi-purpose research reactor) under design study by using the RELAP5/MOD3 code in order to provide the preliminary evaluation of safety margin as well as the intuitions to the design of the MRR. Input and modeling for the RELAP5/MOD3 simulations have also been described. The analysis results indicate that the concept of the MRR is feasible with practical safety margins. The same events have been also analyzed by using the PARET/ANL and the EUREKA-2/RR codes to compare the codes suitability, which have been widely used for the analysis of research reactors. Same geometric and modeling data used for the RELAP5/MOD3 have been used as long as they correspond to each code's input requirements. The three codes show the same or similar overall trends for the events analyzed, but show a small difference in a specific condition.