Q17 — SGFP Trip Load Reduction
059 MFW-AA2.06 (2.7)
Given:
• Unit 2 is at 100% Reactor Power and stable
At time 09:00:00
• 22 SGFP trips
At time 09:00:15 (15 seconds later)
• The crew enters S2.OP-AB.CN-0001 (MAIN FEEDWATER/CONDENSATE SYSTEM ABNORMALITY)
• Unit 2 is at 100% Reactor Power
In accordance with S2.OP-AB.CN-0001, which ONE of the following completes the statement below?
The crew will initiate a MANUAL Main Turbine load reduction until less than or equal to a MAXIMUM of _(1)_ % Turbine Power at a rate less than or equal to a MAXIMUM of _(2)_ %/MIN.
• Unit 2 is at 100% Reactor Power and stable
At time 09:00:00
• 22 SGFP trips
At time 09:00:15 (15 seconds later)
• The crew enters S2.OP-AB.CN-0001 (MAIN FEEDWATER/CONDENSATE SYSTEM ABNORMALITY)
• Unit 2 is at 100% Reactor Power
In accordance with S2.OP-AB.CN-0001, which ONE of the following completes the statement below?
The crew will initiate a MANUAL Main Turbine load reduction until less than or equal to a MAXIMUM of _(1)_ % Turbine Power at a rate less than or equal to a MAXIMUM of _(2)_ %/MIN.
A. (1) 50 (2) 30
B. (1) 50 (2) 15
C. (1) 66 (2) 30
D. (1) 66 (2) 15
▶ Show Answer & Explanation
✓ D. Correct. IAW S2.OP-AB.CN-0001, the crew will initiate a Main Turbine load reduction until less than or equal to a MAXIMUM of 66% Turbine Power at a rate less than or equal to a MAXIMUM of 15%/MIN.
✗ A. For Part 1, there are only two SGFPs. The candidate could incorrectly conclude that each SGFP provides 50% total flow. Consequently when 22 SGFP trips, the candidate could incorrectly conclude that S2.OP-AB.CN-0001 requires a load reduction to 50% Turbine Power. For Part 2, a loss of stator cooling water will cause an automatic turbine runback at 30%/minute. Consequently, the candidate could incorrectly conclude that the maximum turbine load ramp in S2.OP-AB.CN-0001 is 30%/MIN.
✗ B. For Part 1, the candidate could incorrectly conclude that each SGFP provides 50% total flow and S2.OP-AB.CN-0001 requires a load reduction to 50% Turbine Power. Part 2 is correct.
✗ C. Part 1 is correct. For Part 2, the candidate could incorrectly conclude that the maximum turbine load ramp in S2.OP-AB.CN-0001 is 30%/MIN (confusing with the stator cooling water loss automatic runback rate).
Ref: NOS05ABCN01-06 (Main Feedwater/Condensate System Abnormality) | LO: NOS05ABCN01-06 LO 2 — State the immediate actions of AB.CN-0001 | Source: Modified Bank (ILOT 1601 NRC RO Q17) | Cognitive: Lower
Connections
- Related systems: Feed & Condensate, AFW
- Related procedures: AB.CN-0001 — Condensate System Abnormality
- Related exam: 2019 NRC Written Exam