Q44 — AFW Pump Auto Start on Both SGFP Trip
059000K1.02 (3.4)
Given:
- Unit 2 is performing a Technical Specifications required shutdown in accordance with S2.OP-IO.ZZ-0004, Power Operation.
- 22 SGFP has been removed from service in accordance with S2.OP-SO.CN-0002, Steam Generator Feed Pump Operation.
- Reactor Power is now 24% and the 21 SGFP has just tripped.
With NO operator action, what will be the status of the Auxiliary Feed Pumps?
- Unit 2 is performing a Technical Specifications required shutdown in accordance with S2.OP-IO.ZZ-0004, Power Operation.
- 22 SGFP has been removed from service in accordance with S2.OP-SO.CN-0002, Steam Generator Feed Pump Operation.
- Reactor Power is now 24% and the 21 SGFP has just tripped.
With NO operator action, what will be the status of the Auxiliary Feed Pumps?
A. ONLY the MDAFW pumps start immediately upon the trip of 21 SGFP.
B. ONLY the TDAFW pump starts immediately upon the trip of 21 SGFP.
C. The MDAFW pumps AND the TDAFW pump start immediately upon the trip of 21 SGFP.
D. The MDAFW pumps AND the TDAFW pump start when NR level in 1/4 SGs lowers to 14%.
▶ Show Answer & Explanation
✓ A. Correct. A trip condition on both SGFPs generates an Automatic start of both the MDAFW pumps. S2.OP-SO.CN-0002(Q), Steam Generator Feed Pump Operation will ensure that the removed from service pump is in the tripped condition.
✗ B. Incorrect. Plausible because the candidate may believe that the automatic start signal from the trip of both SGFPs only starts the TDAFW pump. This is incorrect, only the MDAFW pumps get a start signal from the trip of both SGFPs.
✗ C. Incorrect. Plausible because the candidate may believe that the automatic start signal from the trip of both SGFPs also includes the TDAFW pump. This is incorrect, only the MDAFW pumps get a start signal from the trip of both SGFPs.
✗ D. Incorrect. Plausible because the candidate may believe that the removed from service 22 SGFP is not tripped and that all AFW pumps will start on the SG low-low level signal. Incorrect as S2.OP-SO.CN-0002(Q), Steam Generator Feed Pump Operation will ensure that the removed from service pump is in the tripped condition. Also incorrect because the TDAFW pump does not start until 2/4 SGs reach 14%.
Ref: Logic Drawing 221064 (AFW pump starts) | LO: N/A | Source: Bank, Salem 2015 NRC Exam | Cognitive: Fundamental
Connections
- Related systems: AFW, Feed & Condensate
- Related procedures: S2.OP-SO.CN-0002 — Steam Generator Feed Pump Operation, S2.OP-IO.ZZ-0004 — Power Operation
- Related exam: 2020 NRC Written Exam