Q78 — AB.CN-0001 Peer Checks and Polisher Bypass
APE: 054 Loss of Main Feedwater (MFW)-G2.1.6 (4.8)
Given:
• Unit 2 is at 95% Reactor Power and stable
• Condensate Polishing is in service
• The crew is implementing S2.OP-AB.CN-0001 (Main Feedwater / Condensate System Abnormality) IMMEDIATE ACTIONS
At time 12:00
• 21 Header Drain Pump has tripped
• SGFP suction pressure is 310 psig and lowering
Which ONE of the following completes the statements below?
During performance of S2.OP-AB.CN-0001 IMMEDIATE ACTIONS, HU-AA-101 (Human Performance Tools And Verification Practices) states that Peer Checks are _(1)_ (during transients).
With SGFP suction pressure at 310 psig and lowering, S2.OP-AB.CN-0001 directs the crew to FIRST open _(2)_ in an effort to restore SGFP suction pressure.
• Unit 2 is at 95% Reactor Power and stable
• Condensate Polishing is in service
• The crew is implementing S2.OP-AB.CN-0001 (Main Feedwater / Condensate System Abnormality) IMMEDIATE ACTIONS
At time 12:00
• 21 Header Drain Pump has tripped
• SGFP suction pressure is 310 psig and lowering
Which ONE of the following completes the statements below?
During performance of S2.OP-AB.CN-0001 IMMEDIATE ACTIONS, HU-AA-101 (Human Performance Tools And Verification Practices) states that Peer Checks are _(1)_ (during transients).
With SGFP suction pressure at 310 psig and lowering, S2.OP-AB.CN-0001 directs the crew to FIRST open _(2)_ in an effort to restore SGFP suction pressure.
A. _(1)_ required _(2)_ 2CN47 (23/24/25 Heater Strings Bypass)
B. _(1)_ required _(2)_ 21/22/23CN108 (Bypass Polisher Valves)
C. _(1)_ desired but NOT required _(2)_ 2CN47 (23/24/25 Heater Strings Bypass)
D. _(1)_ desired but NOT required _(2)_ 21/22/23CN108 (Bypass Polisher Valves)
▶ Show Answer & Explanation
✓ D. Correct. For Part 1 and IAW HU-AA-101 Step 4.8.6, "Peer checks for actions necessary to mitigate a transient are desired but not required". For Part 2 and IAW S2.OP-AB.CN-0001 Steps 3.20 through 3.22, the crew will FIRST open 21/22/23CN108 (Bypass Polisher Valves) in an effort to restore SGFP suction pressure.
✗ A. For Part 1, the candidate could incorrectly conclude that Peer Checks are required for all IMMEDIATE ACTIONS. For Part 2, opening 2CN47 will be opened after 21/22/23CN108s are opened to restore SGFP suction pressure. Consequently, the candidate could incorrectly conclude that S2.OP-AB.CN-0001 requires 2CN47 to be opened first.
✗ B. For Part 1, the candidate could incorrectly conclude that Peer Checks are required for all IMMEDIATE ACTIONS. Part 2 is correct.
✗ C. Part 1 is correct. For Part 2, opening 2CN47 will be opened after 21/22/23CN108s are opened to restore SGFP suction pressure. Consequently, the candidate could incorrectly conclude that S2.OP-AB.CN-0001 requires 2CN47 to be opened first.
Ref: S2.OP-AB.CN-0001, HU-AA-101 (Human Performance Tools And Verification Practices) | LO: NOS05ABCN01-06 (MAIN FEEDWATER/CONDENSATE SYSTEM ABNORMALITY) | Source: New | Cognitive: Higher
Connections
- Related systems: Feed & Condensate
- Related procedures: AB.CN-0001 — Condensate System Abnormality, HU-AA-101 — Human Performance Tools and Verification Practices
- Related exam: 2018 NRC Written Exam