Q37 — PZR Pressure Channel Fails High / DNBR Limit
010 A1.07 (3.7)
Given:
• Unit 2 is at 100% Power
• All systems are in normal alignment and in AUTO
• The controlling PZR Pressure channel fails HIGH
Which ONE of the following completes both statements?
1. In order to restore RCS pressure to program, the RO will manually _(1)_ demand on the Master Pressure Controller.
2. If RCS pressure lowers to less than _(2)_ psig, LCO 3.2.5, DNB Parameters, for minimum DNBR will NOT be MET.
• Unit 2 is at 100% Power
• All systems are in normal alignment and in AUTO
• The controlling PZR Pressure channel fails HIGH
Which ONE of the following completes both statements?
1. In order to restore RCS pressure to program, the RO will manually _(1)_ demand on the Master Pressure Controller.
2. If RCS pressure lowers to less than _(2)_ psig, LCO 3.2.5, DNB Parameters, for minimum DNBR will NOT be MET.
A. _(1)_ lower / _(2)_ 2200
B. _(1)_ lower / _(2)_ 2185
C. _(1)_ raise / _(2)_ 2200
D. _(1)_ raise / _(2)_ 2185
▶ Show Answer & Explanation
✓ B. Correct. A failed high controlling PZR pressure channel will raise the demand of the MPC to 100% and opening all spray valves. The Master Pressure Controller (MPC) demand will have to be lowered in order to close the spray valves and turn on all the PZR heaters to restore RCS pressure to program. The TS limit for minimum DNBR for RCS Pressure is ≥ 2200 psia (or < 2185 psig).
✗ A. Incorrect. First part is correct. Second part is incorrect. The TS limit for minimum DNBR for RCS Pressure is ≥ 2200 psia (or < 2185 psig).
✗ C. Incorrect. First part is incorrect. A failed high controlling PZR pressure channel will raise the demand of the MPC to 100% and opening all spray valves. Second part is incorrect. The TS limit for minimum DNBR for RCS Pressure is ≥ 2200 psia (or < 2185 psig).
✗ D. Incorrect. First part is incorrect. A failed high controlling PZR pressure channel will raise the demand of the MPC to 100% and opening all spray valves. Second part is correct.
Ref: NOS05PZRP&L-12, TS LCO 3.2.5 | LO: NOS05PZRP&L-12, Obj 15 — Given a PZR Pressure and Level Control System failure, predict the effect on the RCS | Source: New | Cognitive: Comprehension/Analysis
Connections
- Related systems: Pressurizer Level & Press Control
- Related tech specs: TS 3/4.2 — Power Distribution
- Related exam: 2022 NRC Written Exam