Post-accident instrumentation must be environmentally qualified to withstand which conditions in the post-LOCA containment atmosphere?

Post-accident instrumentation must be environmentally qualified to withstand which conditions in the post-LOCA containment atmosphere?

• A. Cold, dryness, and low pressure
• B. Heat, humidity, and pressure
• C. Heat, humidity, and low temperature
• D. Cold, humidity, and high humidity

Answer: (B)

After a LOCA, the containment atmosphere becomes dominated by steam—hot, very humid air under elevated pressure. Instruments must be environmentally qualified to survive that harsh environment so they can still function when needed. This means the qualification envelope includes heat, humidity, and pressure. The other options don’t match what actually happens: cold or dry conditions aren’t representative of a post-LOCA containment, and the humidity/temperature combinations outside steam-filled, pressurized conditions wouldn’t reflect the real environment.

After a LOCA, the containment atmosphere becomes dominated by steam—hot, very humid air under elevated pressure. Instruments must be environmentally qualified to survive that harsh environment so they can still function when needed. This means the qualification envelope includes heat, humidity, and pressure. The other options don’t match what actually happens: cold or dry conditions aren’t representative of a post-LOCA containment, and the humidity/temperature combinations outside steam-filled, pressurized conditions wouldn’t reflect the real environment.