Q86 — RCP Seal Failure / Standpipe Level
T2G1 003 A2.01 (4.0)
Given:
• Salem Unit 2 is at 100% power
Then:
• Console Alarm, STANDPIPE LEVEL-LO, is now LIT
• The RO reports the following for 21 RCP:
- Seal Leak-off recorder indicates 1.5 gpm and steady
- Seal Injection Flow indicates 8.5 gpm
Which of the following completes both statements?
1. Which RCP seal failed?
2. What action(s) will the CRS direct the crew?
Note: ARP = Alarm Response Procedure
S2.OP-AB.RCP-0001, Reactor Coolant Pump Abnormality
• Salem Unit 2 is at 100% power
Then:
• Console Alarm, STANDPIPE LEVEL-LO, is now LIT
• The RO reports the following for 21 RCP:
- Seal Leak-off recorder indicates 1.5 gpm and steady
- Seal Injection Flow indicates 8.5 gpm
Which of the following completes both statements?
1. Which RCP seal failed?
2. What action(s) will the CRS direct the crew?
Note: ARP = Alarm Response Procedure
S2.OP-AB.RCP-0001, Reactor Coolant Pump Abnormality
A. 1) #3 seal — 2) Perform an orderly shutdown and stop 21 RCP within 8 hours per S2.OP-AB.RCP-0001.
B. 1) #3 seal — 2) Make-up to the standpipe per the ARP; power operation may continue.
C. 1) #2 seal — 2) Make-up to the standpipe per the ARP; power operation may continue.
D. 1) #2 seal — 2) Perform an orderly shutdown and stop 21 RCP within 8 hours per S2.OP-AB.RCP-0001.
▶ Show Answer & Explanation
✓ B. Correct. The conditions in the stem describes a #3 seal leak. Standpipe level low is a primary indicator that the #3 seal is leaking only since the #1 seal leakoff flow is steady at 1.5 gpm which is normal conditions for an intact #2 seal. The crew will take action per the console ARP and perform a makeup to clear the low standpipe level alarm and initiate S2.OP-ST.RC-0008 for RCS leak rate. The CRS could enter S2.OP-AB.RCP-0001 based on the console alarm, but the AB will not provide any direction for a leaking #3 seal.
✗ A. Part 1 is correct. Part 2 is incorrect. Plausible because this is an action in S2.OP-AB.RCP-0001 for a leaking or degraded #2 seal.
✗ C. Part 1 is incorrect. Plausible because the operator may confuse the standpipe level indications in the stem as signs of a #2 seal leak. Part 2 is correct.
✗ D. Part 1 is incorrect. Plausible because the operator may confuse the standpipe level indications in the stem as signs of a #2 seal leak. Part 2 is incorrect. Plausible because this is an action in S2.OP-AB.RCP-0001 for a leaking or degraded #2 seal.
Ref: S2.OP-AB.RCP-0001 (R28) | LO: NOS05ABRCPUMP-18, Obj 17.b — Given appropriate control room reference material, evaluate and determine the effect on the Reactor Coolant Pump: Degraded Reactor Coolant Pump seals and seal water | Source: Modified Bank - Diablo Canyon 2019 NRC SRO86 | Cognitive: Comprehension/Analysis
Connections
- Related systems: RCPs
- Related procedures: AB.RCP-0001 — RCP Abnormality
- Related exam: 2023 NRC Written Exam