The prototype fast breeder reactor "MONJU" has an EVSS (ex-vessel fuel storage system) which consists mainly of an EVST (ex-vessel fuel storage tank) and an EVST sodium cooling system. EVST sodium cooling system...The prototype fast breeder reactor "MONJU" has an EVSS (ex-vessel fuel storage system) which consists mainly of an EVST (ex-vessel fuel storage tank) and an EVST sodium cooling system. EVST sodium cooling system consists of three independent loops. During the normal operation, the primary sodium in the EVST is circulated by natural convection and the secondary circulation in the EVST sodium cooling system is powered by electromagnetic pumps. When an SBO (station blackout) occurs, all the pumps and blowers are tripped. Therefore, it was necessary to evaluate the cooling ability by the natural circulation of sodium in the EVST sodium cooling system and air through the air cooler during the SBO. In this study, an analysis and evaluation of the plant dynamics for the spent fuel and the EVSS structural integrity during an SBO were performed. When the number of cooling loops was not changed and natural circulation occurred in only two loops, the sodium temperature in the EVST increased to approximately 450 ~C. However, the structural integrity of the EVSS was maintained. The analytical results, therefore, help clarify the number of necessary cooling loops for efficient decay heat removal and sodium temperature behavior in an SBO.展开更多
CH-HCSB TBM is designed to test the feasibility of DEMO fusion reactor on ITER. A safety assessment has to demonstrate that the TBM with its own cooling system does not impede the safe operation of ITER under normal a...CH-HCSB TBM is designed to test the feasibility of DEMO fusion reactor on ITER. A safety assessment has to demonstrate that the TBM with its own cooling system does not impede the safe operation of ITER under normal and accidental conditions. For analysis of the highly transient accident sequences, a RELAP5 model has been developed for the HCS and TBM system. The steady-state, In-Vessel LOCA, Ex-Vessel LOCA and In-Box LOCA have been analyzed and the designed TBM steady-state inlet/outlet temperatures have been obtained. In all LOCA accidents, the Ex-Vessel LOCA is the most dangerous accident because of the melting of the First Wall. Based on the results, the design of TBM could be modified further in order to improve the safety of TBM and ITER.展开更多
文摘The prototype fast breeder reactor "MONJU" has an EVSS (ex-vessel fuel storage system) which consists mainly of an EVST (ex-vessel fuel storage tank) and an EVST sodium cooling system. EVST sodium cooling system consists of three independent loops. During the normal operation, the primary sodium in the EVST is circulated by natural convection and the secondary circulation in the EVST sodium cooling system is powered by electromagnetic pumps. When an SBO (station blackout) occurs, all the pumps and blowers are tripped. Therefore, it was necessary to evaluate the cooling ability by the natural circulation of sodium in the EVST sodium cooling system and air through the air cooler during the SBO. In this study, an analysis and evaluation of the plant dynamics for the spent fuel and the EVSS structural integrity during an SBO were performed. When the number of cooling loops was not changed and natural circulation occurred in only two loops, the sodium temperature in the EVST increased to approximately 450 ~C. However, the structural integrity of the EVSS was maintained. The analytical results, therefore, help clarify the number of necessary cooling loops for efficient decay heat removal and sodium temperature behavior in an SBO.
文摘CH-HCSB TBM is designed to test the feasibility of DEMO fusion reactor on ITER. A safety assessment has to demonstrate that the TBM with its own cooling system does not impede the safe operation of ITER under normal and accidental conditions. For analysis of the highly transient accident sequences, a RELAP5 model has been developed for the HCS and TBM system. The steady-state, In-Vessel LOCA, Ex-Vessel LOCA and In-Box LOCA have been analyzed and the designed TBM steady-state inlet/outlet temperatures have been obtained. In all LOCA accidents, the Ex-Vessel LOCA is the most dangerous accident because of the melting of the First Wall. Based on the results, the design of TBM could be modified further in order to improve the safety of TBM and ITER.