Q93 — Loss of Control Air Reactor Trip
079 SAS-A2.01 (3.2)
Given:
• Unit 1 is at 25% Power and stable
• The crew is performing S1.OP-AB.CA-0001 (Loss Of Control Air) due to a leak on the cross connect line between Station Air and the Unit 1 Control Air
• 1A Control Air Header Pressure is 79 psig
• 1B Control Air Header Pressure is 77 psig
In accordance with S1.OP-AB.CA-0001, which ONE of the following completes the statements below?
The crew's NEXT action will be to
• Unit 1 is at 25% Power and stable
• The crew is performing S1.OP-AB.CA-0001 (Loss Of Control Air) due to a leak on the cross connect line between Station Air and the Unit 1 Control Air
• 1A Control Air Header Pressure is 79 psig
• 1B Control Air Header Pressure is 77 psig
In accordance with S1.OP-AB.CA-0001, which ONE of the following completes the statements below?
The crew's NEXT action will be to
A. CHECK ANY Excess Flow Check Valve closed per S1.OP-AB.CA-0001 Attachment 5 (EXCESS FLOW CHECK VALVE TABLE)
B. TRIP the Reactor and perform 1-EOP-TRIP-1 (Reactor Trip Or Safety Injection) CONCURRENTLY with S1.OP-AB.CA-0001 Attachment 6 (ABNORMAL COOLING WATER LINEUPS)
C. INITIATE a plant shutdown per S1.OP-IO.ZZ-0004 (POWER OPERATION) while CONCURRENTLY performing S1.OP-AB.CA-0001 Attachment 12 (LOCAL CONTROL OF SG PRESSURE AND LEVEL)
D. TRIP the Reactor and perform 1-EOP-TRIP-1 (Reactor Trip Or Safety Injection) CONCURRENTLY with S1.OP-AB.CA-0001 Attachment 12 (LOCAL CONTROL OF SG PRESSURE AND LEVEL)
▶ Show Answer & Explanation
✓ D. Correct. IAW S1.OP-AB.CA-0001 (Loss Of Control Air) CAS, when BOTH Control Air Headers indicate less than 80 psig, the crew's NEXT action will be to TRIP the Reactor and perform 1-EOP-TRIP-1 (Reactor Trip Or Safety Injection) CONCURRENTLY with S1.OP-AB.CA-0001 Attachment 12 (LOCAL CONTROL OF SG PRESSURE AND LEVEL).
✗ A. Incorrect but plausible. CHECKING ANY Excess Flow Check Valve closed per S1.OP-AB.CA-0001 Attachment 5 (EXCESS FLOW CHECK VALVE TABLE) is only required when at least one control air header is greater than 80 psig. (S1.OP-AB.CA-0001 Step 3.17)
✗ B. Incorrect but plausible. Tripping of the Reactor is correct. However, the crew is not required to perform S1.OP-AB.CA-0001 Attachment 6 (ABNORMAL COOLING WATER LINEUPS) since cooling water to Station or Emergency Air Compressors was not lost.
✗ C. Incorrect but plausible. The candidate could recognize the need to take the plant offline because BOTH Control Air Headers indicate less than 80 psig. However, the candidate could incorrectly conclude that the plant will be shutdown per S1.OP-IO.ZZ-0004 (POWER OPERATION) while CONCURRENTLY performing S1.OP-AB.CA-0001 Attachment 12 (LOCAL CONTROL OF SG PRESSURE AND LEVEL).
Ref: S2.OP-AB.CA-0001 | LO: NOS05ABCA01-07 (LOSS OF CONTROL AIR) | Source: Modified Bank (ILOT 16-01 SRO Q18) | Cognitive: Lower
Connections
- Related procedures: AB.CA-0001 — Loss of Control Air
- Related systems: Control Air
- Related EOPs: EOP-TRIP-1 — Reactor Trip or Safety Injection
- Related exam: 2019 NRC Written Exam