Q43 — AFW 2MS132 Instrument Air Supply Rupture
T2G1 061 A2.07 (4.0)
Given:
• Salem Unit 2 is at 100% power
• Instrument air supply line to 2MS132, 23 AFW Turbine Steam Inlet Valve, ruptures
Which of the following completes both statements?
1. What is the status of 23 AFW Pump?
2. What action should the operator take FIRST?
• Salem Unit 2 is at 100% power
• Instrument air supply line to 2MS132, 23 AFW Turbine Steam Inlet Valve, ruptures
Which of the following completes both statements?
1. What is the status of 23 AFW Pump?
2. What action should the operator take FIRST?
A. (1) Running (2) Reduce reactor power to prevent overpower condition per S2.OP-IO.ZZ-0004, Power Operation
B. (1) Running (2) Take manual control of the Main Feedwater Regulating valves to prevent SG overfill per S2.OP-AB.CA-0001, Loss of Control Air.
C. (1) NOT Running (2) Enter Tech Spec LCO 3.7.1.2, Auxiliary Feedwater System for INOPERABLE AFW Pump.
D. (1) NOT Running (2) Fail open the 2MS132 by using the handwheel on the valve actuator per S2.OP-AB.CA-0001, Loss of Control Air.
▶ Show Answer & Explanation
✓ A. Correct. Air supply line rupturing on the 2MS132 will cause the AFW steam inlet valve to fail open. This will result in 23 AFW running and injecting cold feedwater into the SGs. As a result, reactor power will increase above the 100% RTP and the operator should reduce reactor power per S2.OP-IO.ZZ-0004, Power Operation. Per S2.OP-IO.ZZ-0004, the maximum power level is 3459 MWt (100% RTP).
✗ B. Incorrect. Part 1 is correct. Part 2 is incorrect. Plausible because with 23 AFW running additional feedwater is being supplied to all the SGs. Incorrect in that with digital feedwater system in Automatic, the MFW Regulating Valves will automatically adjust demand to maintain SG NR levels within program band.
✗ C. Incorrect. Plausible because the operator may incorrectly recall how the valve fails on loss of air and believe the 2MS132 fails closed thereby preventing the start of 23 AFW pump. Entering TS LCO 3.7.1.2 is plausible because this LCO is applicable for the 23 AFW pump condition.
✗ D. Incorrect. Plausible because the operator may incorrectly recall how the valve fails on loss of air and believe the 2MS132 fails closed thereby preventing the start of 23 AFW pump. Failing open the 2MS132 is plausible because many AOVs can be locally operated.
Ref: NOS05AFW000-18, S2.OP-IO.ZZ-0004 (R88) | Source: Bank — Salem | Cognitive: Comprehension/Analysis
K/A: 061 A2.07 — Ability to (a) predict the impacts of the following on the Auxiliary Emergency Feedwater System and (b) based on those predictions, use procedures to correct, control, or mitigate the consequences of those abnormal operations: Air operated valve, solenoid-operated valve, or motor-operated valve
K/A: 061 A2.07 — Ability to (a) predict the impacts of the following on the Auxiliary Emergency Feedwater System and (b) based on those predictions, use procedures to correct, control, or mitigate the consequences of those abnormal operations: Air operated valve, solenoid-operated valve, or motor-operated valve
Connections
- Related systems: AFW, Main Steam
- Related procedures: S2.OP-IO.ZZ-0004 — Power Operation, AB.CA-0001 — Loss of Control Air
- Related exam: 2023 NRC Written Exam