An estimation of an operator's action time by using the MARS code in a small break LOCA without a HPSI for a PWR

RELAP5/MOD3.3 Best Estimate Analyses for Human Reliability Analysis

“…If uncertainty analysis would be needed same approach could be followed as for licensing LOCA calculations, for example, [18]. On the other hand, the authors in [19] are of the opinion that the uncertainty is a less important issue for the treatment of an operator's action in a thermal hydraulic simulation and that better approach is to estimate the time window conservatively. Nevertheless, such a statement could be used only when additional available time is sufficient to take into account conservatism.…”

“…To estimate the time windows for operator actions the results of fast running severe accident code such as the MAAP code have been used in the conventional probabilistic safety assessment (PSA). However, information from these is often too conservative to perform a realistic PSA for a riskinformed application [3]. In the last years a few comparative studies were performed to justify the use of MAAP4 for the PSA Level 1 analysis of advanced reactors [4,5].…”

“…To reduce the undue conservatism, the use of bestestimate thermal hydraulic code has become an essential issue in the latest PSA. An example is the use of MARS code for small break LOCA calculations of Korea standard nuclear power plant [3] and the use of RELAP5/MOD3.2 code for LOCA calculations of RBMK-1500 [6]. Also the PSA standard [7] recommends the use of best-estimate code to improve the quality of a PSA.…”

Accident Management Actions in an Upper-Head Small-Break Loss-of-Coolant Accident with High-Pressure Safety Injection Failed

“…Several options of this manual control have been checked similar to the models described in Ref. 60. After adjusting the parameters of all the manual control models, a proportional control was selected.…”

Success criteria time windows of operator actions using RELAP5/MOD3.3 within human reliability analysis

“…Wherever, due to lack of information, the models were incomplete, the worst case was examined and considered. Realistic deterministic safety analyses have been required recently (ASME RA-S-2002RA-S- , 2002Han, Lim, & Yang, 2007) for risk-informed applications. So, the realistic i.e.…”