Time Window Calculations of Operator Action During a MSLBI for a Typical 2-Loops PWR

In some cases of SCA framework, it is needed to obtain the available time for human action, to achieve this, TWC of operator action is carrying out and it is intended for determining the realistic needed time of operator initiation action during diffrent sequences of an accident. This study performs TWC in the case of MSLBI for a typical 2-loops PWR. during this accident, When the EFW is not available, the operator action of PF B is required to remove the decay heat. The objective of this study is to calculate the necessary time of operator action to initiate the PF B in order to prevent the core damage end state. According to the event tree, the 2nd and 7th sequences of the accident which the operator’s action is needed and the necessary time of initiating PF B is calculated for both sequences. reults for the 2nd sequence, showed that 55 minutes and 135 minutes are the almost maximum available time for operator with and without operation of a PSV respectively. The results of 7th sequence indicated that 50 minutes and 135 minutes are the almost maximum available time for operator with and without operation of a PSV respectively.