Safety analysis of the U reactor

In the framework of the MYRRHA project. an experimental fast-spectrum irradiation facility operated with lead Bismuth Eutectic (LBE) coolant and able to operate in both sub-cntical and critical mode is designed to be built in Mol. Belgium In addition to material testing, the objectives of the MYRRllA reactor are to prove live feasibility of the ADS technology as Minor Actinidcs burner and to act as a demonstration plant for future Generation IV heavy metal cooled reactors. SCK-CF.N entered the prc-licensing phase for the MYRRHA reactor. Safety analyses of the MYRRHA system using system codes arc currently performed within the European framework Program project MAXSIMA. The analyses arc aimed at the verification of the capability of the safety systems to bring the reactor to a safe shutdown state after a postulated accidental event, The safety analyses focus on three different categories of transient events, including protected transients to analyze the protection system and decay heat removal system capabilities, protected transients to check on the ovcrcooling nsk and unprotected transients to define and set up the protection requirements. This paper describes the results obtained with the RILAP5-3D ver. 4.0.3 system code on three selected transients for the latest design version of MYRRHA: loss of ofTsite power, overcooling + loss of How and unprotected loss of flow. In addition to the deterministic transient studies, the MAXSIMA project foresees the application of uncertainty quantification techniques. The capabilities of the Uncertainty + Sensitivity (U + S) analysis application SIJSA is illustrated in this paper for the unprotected loss of flow accident.