The accident that occurred at the TMI-2 plant and the LP-FP-2 experiment conducted in the integral facility LOFT (Idaho National Laboratory) provided unique and valuable data for severe accident code assessment. Both the TMI-2 accident and the LP-FP-2 experiment were characterized by the loss of primary coolant with consequent core uncovery and heat-up that resulted in severe core damage. Both transients were terminated by core reflood with enhanced hydrogen generation and molten core material slumping into the lower plenum in case of TMI-2. These accidental transients have been analyzed with ASTEC V2 system code with the aim to validate and verify the coupling between the ICARE core degradation module and the CESAR module employed for the evaluation of the thermal-hydraulic behaviour of the primary circuit. The improved debris bed and magma models available in the latest version V2.0 of the code have been used to describe the late-phase of core melt progression. The comparison of code results with the available data has highlighted the globally good capability of the code to simulate the thermal-hydraulics of the primary circuit and the core melt progression during both early and late degradation phases, while code model weaknesses are observed in the analysis of the core reflood phase. © 2013 Elsevier B.V.
ASTEC validation on TMI-2 and LOFT LP-FP-2
De Rosa, F.;Bandini, G.
2014-01-01
Abstract
The accident that occurred at the TMI-2 plant and the LP-FP-2 experiment conducted in the integral facility LOFT (Idaho National Laboratory) provided unique and valuable data for severe accident code assessment. Both the TMI-2 accident and the LP-FP-2 experiment were characterized by the loss of primary coolant with consequent core uncovery and heat-up that resulted in severe core damage. Both transients were terminated by core reflood with enhanced hydrogen generation and molten core material slumping into the lower plenum in case of TMI-2. These accidental transients have been analyzed with ASTEC V2 system code with the aim to validate and verify the coupling between the ICARE core degradation module and the CESAR module employed for the evaluation of the thermal-hydraulic behaviour of the primary circuit. The improved debris bed and magma models available in the latest version V2.0 of the code have been used to describe the late-phase of core melt progression. The comparison of code results with the available data has highlighted the globally good capability of the code to simulate the thermal-hydraulics of the primary circuit and the core melt progression during both early and late degradation phases, while code model weaknesses are observed in the analysis of the core reflood phase. © 2013 Elsevier B.V.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.