Optimum RCS depressurization strategy for effective severe accident management of station black out accident

Evaluation of Samg Effectiveness in View of Group Decision

“…We analyzed the operator's actions to determine if they are realistic and effective, and if the guidelines really enhance the plant's capability to handle severe accidents in terms of mitigating the negative impacts of each action in the accident progression. In the following, we summarize the evaluation results of our previous studies [3][4][5], and we believe the conclusions are still valid for the SAMGs of many other operating plants.…”

“…It was shown that once we could depressurize the RCS, the HPME/DCH is not an issue because the system pressure at the time of vessel failure becomes lower than the pressure limit to prevent the phenomena. [5] In paper [5], it was also shown that the RCS inventory needs to be used more economically for an improved RCS depressurization strategy. The rapid depressurization could delay the onset of core degradation for one hour while the water inventory available depletes rapidly.…”

“…Many studies on SAMG strategies have been performed to develop more effective severe accident management strategies [5,13,14], but no research result that takes into account this group polarization on an organizational framework is available. In order to highlight the TSC group decision-making process under a risky condition and thus propose the direction for the development of a severe accident management guideline, we would like to recapitulate previous studies by the authors.…”

“…The details of the simulation can be found in the authors' paper. [5] Rapid depressurization is required in Mitigation-02 as shown in Table 1. Looking at Table 2 of the present SAMG, the TSC needs to decide a strategy to implement evaluating the negative and positive impacts.…”

Validation of RCS depressurization strategy and core coolability map for independent scenarios of SBLOCA, SBO, and TLOFW

“…This code is to treat the entire spectrum of severe accident phenomena, including reactor coolant system and containment thermal-hydraulic response, core heat-up, degradation and relocation, and fission product release and transport, in a unified framework for both PWR and BWR [13,14]. MELCOR code is mostly used by regulatory body and academic researchers to evaluate strategies for severe accident mitigation and to simulate detailed features of severe accident sequences [15][16][17][18][19][20]. In Korea, for a successful severe accident management, an AtomCARE system has been developed for collection of SAMG variables connecting plant monitoring program with MELCOR [21].…”