As part of ARS’s mission of working with clients to develop strategies to minimize the risk of fire in nuclear power plants, we have developed a tool to assist in calculating fire ignition frequency.  Under Task 6 of the NUREG/CR-6850 guidance, plants evaluate the likelihood of fires caused by possible ignition sources identified on plant walkdowns.  The engineers at ARS have developed a Fire Ignition Frequency Database to determine this likelihood and how it affects fire modeling and fire probabilistic risk assessment modeling.

ARS engineers have created customized database tools that calculate the results of Task 6 of the NUREG/CR-6850.  The resulting fire ignition frequency is used in fire modeling as well as in performing Task 11 of NUREG/CR-6850: detailed fire models and the PRA notebook.  In addition to streamlining the calculations involved in Task 6, the creation of the Fire Ignition Frequency Database allows the ARS fire protection engineers to recalculate quickly and accurately if plant data changes.