Recommended by Oleg Novoselsky A systematic study of natural circulation (NC) in a postulated, varying primary mass inventory scenario at residual power fractions has been performed for a nuclear power plant operating in Argentina. It is a pressurized heavy water reactor, cooled and moderated by heavy water. The analysis seems particularly relevant at present, because a second nuclear power plant (NPP), of similar design and nearly 745 MWe, is now under finalization. NRC-RELAP5/MOD3.3 was the code used to perform the simulations. Results obtained are presented in the form of natural circulation flow maps. The trends obtained fit in the expected limits for integral test facilities representative of PWRs. In addition, the validity of a simplified analysis to scale single and two-phase core flow has been verified. A set of constants has been obtained, which permits predicting NC core mass flow rate (CMFR) for this NPP. Results are partially validated, for single-phase NC flow, using a documented plant transient, showing reasonable agreement. Also, the effect of pressurizer size on the predicted evolution curve in the NC flow map (NCFM) is discussed.
Natural Circulation in the ATUCHA-I PHWR Nuclear Power Plant
D'AURIA, FRANCESCO SAVERIO;
2007-01-01
Abstract
Recommended by Oleg Novoselsky A systematic study of natural circulation (NC) in a postulated, varying primary mass inventory scenario at residual power fractions has been performed for a nuclear power plant operating in Argentina. It is a pressurized heavy water reactor, cooled and moderated by heavy water. The analysis seems particularly relevant at present, because a second nuclear power plant (NPP), of similar design and nearly 745 MWe, is now under finalization. NRC-RELAP5/MOD3.3 was the code used to perform the simulations. Results obtained are presented in the form of natural circulation flow maps. The trends obtained fit in the expected limits for integral test facilities representative of PWRs. In addition, the validity of a simplified analysis to scale single and two-phase core flow has been verified. A set of constants has been obtained, which permits predicting NC core mass flow rate (CMFR) for this NPP. Results are partially validated, for single-phase NC flow, using a documented plant transient, showing reasonable agreement. Also, the effect of pressurizer size on the predicted evolution curve in the NC flow map (NCFM) is discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.