Review Article
Station Black-Out Analysis with MELCOR 1.8.6 Code for Atucha 2
Nuclear Power Plant
Table 2
CNA-2 PHWR NPP versus German PWR—timing of events in an SBO.
| | Plant characteristic | CNA-2 PHWR low pressure SBO MELCOR | Ref. German PWR KONVOI low pressure SBO MELCOR |
| | Core thermal power (MW) (total) | 2160 | 3765 | | Core decay power (MW) at reactor scram | 129.6 | 241.9 | | Total volume of primary system (m3) | 520 | 415 | | Primary system volume to core power ratio (m3/MW) | 0.241 | 0.110 |
| | Event listed for CNA-2 PHWR/Event listed for PWR | Time (h:m) | Time (h:m) |
| | SG dryout | ~2:00 | 0:57 | | PRZ SV failure stuck open | 2:31 | — | | Start of uncovery of core/moderator tank | 3:00/3:00 | ~2:10/— | | Total uncovery of core/moderator tank | 3:30/9:00 | ~4:30/— | | Gap release from fuel | 3:56 | 2:22 | | Beginning of core channel failure (PHWR), respectively Core failure and debris formation (PWR) | 5:16 | 2:35 | | Failure of surge line due to creep rupture followed by accumulator injection | — | 2:55 | Fuel relocation to moderator tank bottom (PHWR)
Molten pool formation in core (PWR) | >5:30 | >4 h | | Failure of moderator tank bottom (PHWR)/core support plate (PWR) and debris relocation to lower head | 11:17 | 5:02 | | RPV failure | 23:45 | 6:22 |
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