Ashley MossaWestinghouse PRA Engineer

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.

Typical MCR

Importance of the MCR Redundancy & diversity throughout the plant However MCR is where all instrumentation and

controls come together.

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

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

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)

500 18.6600 13.4700 11.8800 11.0900 10.41000 9.91200 9.21500 8.21700 7.92000 7.2

Questions?