Q14 — Control Air / PORV Accumulators and Spray Valves
APE 65 AA1.03 (3.1)
Given:
• Unit 2 reactor trip + SI
• Instrument air to containment isolated
• PORVs cycling on accumulators
• Then air restored
What is the effect on PORV accumulators and pressurizer spray valves?
• Unit 2 reactor trip + SI
• Instrument air to containment isolated
• PORVs cycling on accumulators
• Then air restored
What is the effect on PORV accumulators and pressurizer spray valves?
A. Accumulators will realign, spray will NOT reopen
B. Accumulators will NOT realign, spray will NOT reopen
C. Accumulators will NOT realign, spray will reopen
D. Accumulators will realign, spray will reopen
▶ Show Answer & Explanation
✓ D. Correct. PORV air accumulators automatically isolate and realign to normal containment control air when pressure restored (>90 psig normal, <85 psig accumulator). Master Pressure Controller will have demand to open spray valves, so both spray valves reopen when air restored.
✗ A. Spray valves will reopen when air restored due to Master Pressure Controller demand. Accumulator realignment is correct but spray valve effect is wrong.
✗ B. Accumulators automatically realign when air pressure is restored, no manual action required. Spray valves will also reopen.
✗ C. Accumulators automatically realign when containment air pressure is restored. Spray valve effect is correct but accumulator effect is wrong.
Ref: NOS05CONAIR-13 | LO: NOS05CONAIR-13, Obj 4.b | Source: New | Cognitive: Comprehension/Analysis
Connections
- Related systems: Pressurizer & PRT, CAV
- Related exam: 2023 NRC Written Exam