Q9 — PZR Spray Valve Failure
APE 27 AK3.03 (3.7)
Given:
• Unit 1 is at 100% Power.
• ALL systems are in AUTO.
• 1PS1, PZR Spray Valve, fails open.
• All PZR Heaters have energized.
• The RO places 1PS1 in manual and will NOT close
In accordance with S1.OP-AB.PZR-0001, Pressurizer Pressure Malfunction, which ONE of the following completes both statements?
1. The reactor is required to be tripped when RCS pressure lowers to __(1)__ psig.
2. The reason this action is performed is to prevent challenging an automatic reactor trip on __(2)__.
• Unit 1 is at 100% Power.
• ALL systems are in AUTO.
• 1PS1, PZR Spray Valve, fails open.
• All PZR Heaters have energized.
• The RO places 1PS1 in manual and will NOT close
In accordance with S1.OP-AB.PZR-0001, Pressurizer Pressure Malfunction, which ONE of the following completes both statements?
1. The reactor is required to be tripped when RCS pressure lowers to __(1)__ psig.
2. The reason this action is performed is to prevent challenging an automatic reactor trip on __(2)__.
A. 1. 1900
2. OTΔT
2. OTΔT
B. 1. 1900
2. Low PZR pressure
2. Low PZR pressure
C. 1. 2000
2. Low PZR pressure
2. Low PZR pressure
D. 1. 2000
2. OTΔT
2. OTΔT
▶ Show Answer & Explanation
✓ D. Correct. With the 1PS1 spray valve failed open, RCS pressure will rapidly lower. Based on the rapidly lowering RCS pressure, S1.OP-AB.PZR-0001 will direct the crew to manually trip the reactor, when RCS pressure is 2000 psig and lowering. The bases in the procedure states that the reason a manual reactor trip is performed is to prevent challenging the automatic reactor trip on OTΔT.
✗ A. First part is incorrect. Plausible because the automatic reactor trip for low pressure is 1865 psig and is rate compensated, tripping the reactor at 1900 psig would be above the automatic setpoint. Second part is correct.
✗ B. First part is incorrect. Second part is incorrect. Plausible because the applicant may believe that the first reactor trip condition reached would be on low PZR pressure since RCS pressure is dropping rapidly. The automatic reactor trip for low pressure is 1865 psig and is rate compensated, tripping the reactor at 1900 psig would be above the automatic setpoint.
✗ C. First part is correct. Second part is incorrect. Plausible because the applicant may believe that the first reactor trip condition reached would be on low PZR pressure since RCS pressure is dropping rapidly.
Ref: S1.OP-AB.PZR-0001 | LO: NOS05PZRPL, Objective 15 | Source: New | Cognitive: Comprehension/Analysis
Connections
- Related systems: Pressurizer & PRT
- Related procedures: AB.PZR-0001 — Pressurizer Pressure Control Malfunction
- Related exam: 2022 NRC Written Exam