The analysis of TMI-2 accident has been performed using the SCDAP/RELAP5/MOD3.2 code which is being developed by INEEL for the U.S. NRC. The code is designed to describe the overall reactor coolant system thermal-hydraulic response and core damage progression during a severe accident in light water reactors. The analysis of TMI-2 accident has been performed within the COBE project of the 4th Framework European Programme on Nuclear Fission Safety up to the end of the phase 2. The TMI-2 input deck for SCDAP/RELAP5 code was prepared according to the ICAREICATHARE calculation performed by CEA/IPSN. In general, the SCDA/RELAP5 results were in substantial agreement with ICARE/CATHARE. In a successive step, the SCDAP/RELAP5 analysis was extended to the phases 3 & 4 of the accident including core reflood and late degradation phase. The total hydrogen generation computed before reflood was in good agreement with TMI-2 data. The hydrogen generation computed during the reflood phase was slightly higher than the one estimated in the TMI-2 accident The state of the core, just prior the estimated core slumping at 225 min, was reasonably well predicted by the code. No molten pool crust failure and material slumping to the lower head was computed by the code during the phase 4. The sensitivity analysis to ZrO2 layer failure criteria showed that this parameter may affect significantly both hydrogen generation and core melt progression in the TMI-2 transient analysis.
|Titolo:||Core Degradation and Hydrogen Generation in the TMI-2 Accident with SCDAP/RELAP5|
|Data di pubblicazione:||19-ott-1999|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|