1. Ashley Mossa Westinghouse PRA Engineer

2. Nuclear 411  Fire Protection has been a “hot” topic since the Browns Ferry Fire in 1975  The Main Control Room (MCR) contains instrumentation & control for virtually all plant equipment and is used to shut down the plant  An alternate shutdown panel can be used in case of MCR evacuation  An industry move to a new fire protection program NFPA 805 is costing NPPs millions of dollars in analyses and plant modifications.

3. Typical MCR

4. Importance of the MCR  Redundancy & diversity throughout the plant  However MCR is where all instrumentation and controls come together.

5. Problem Statement  Determine, for a variety of fire sizes, when operators must abandon the control room due to habitability concerns.  Temperature  Heat Flux  Optical Density  Using the data above, determine the probability of operators leaving the control room

6. Project Steps  Understand FDS  Build FDS Code  Run for a variety of fire sizes & conditions  Analyze results  Determine the probability of operators abandoning the MCR for the ASP

9. Results for Non-Ventilated Case  Non-vented fires of 400kW or less did not require MCR abandonment Fire Size in kW (HRR) Fastest Time to Damage (minutes) 50018.6 60013.4 70011.8 80011.0 90010.4 10009.9 12009.2 15008.2 17007.9 20007.2

10. Questions?