A key part of the safety framework of a Nuclear Power Plant (NPP) is represented by the containment behaviour. The GOTHIC thermal hydraulic code has been employed for evaluating the Atucha-I NPP containment responses during two postulated severe accident scenarios, Station Black Out and Large Break Loss of Coolant Accident without Safety Injection Pumps, while assuming that the external cooling of the Reactor Pressure Vessel is carried out during the transients. The target of the analyses is the evaluation of the effects caused by the additional production of steam in the reactor cavity as a consequence of the external vessel cooling. This could lead to pressure values above the safety limit. The containment pressure, temperature, the distribution of hydrogen and the liquid level have been analysed as target variables. Two different nodalizations were used, a “detailed” nodalization, meant to have the most refined according to the available computational resources, and a “coarse” nodalization in order to lower the computational requirements, without significantly compromising the global response. Several sensitivities were simulated for 100,000 seconds and were meant to understand and characterize the impact of the different nodalization parameters (geometrical aspects, material properties, Boundary Conditions) and as such also provide some indications of some important uncertainty parameters contribution.
|Titolo:||Atucha-I NPP Containment Sensitivity Calculations to Support Uncertainty Evaluations|
POP, ALEXANDRU (Primo)
|Anno del prodotto:||2018|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|