Q79 — Loss of RHR Breaker Reclosure Policy
T1G1 APE 25 G2.1.1 (4.2)
Given:
- Salem Unit 2 is in MODE 5
- 21 RHR Pump is in shutdown cooling
- 22 RHR Pump is in standby
Then:
- 21 RHR Pump trips
- The crew enters S2.OP-AB.RHR-0001, Loss of RHR
- Attempt to start 22 RHR Pump results in the breaker tripping free
- STA reports Time to Core Boiling is less than 15 minutes
- Field operator reports no protective relay flags are present and no obvious reason for the 4KV breaker for 22 RHR Pump to trip free, and an acrid smell is observed near the 21 RHR 4KV breaker cubicle
In accordance with OP-SA-108-106-1001, Equipment Control and Large Motor Starting Criteria, complete the following statement concerning breaker re-closure for 22 RHR Pump?
Based on the above conditions, the (1) can authorize one attempt at reclosing the breaker without an investigation ONLY during (2).
- Salem Unit 2 is in MODE 5
- 21 RHR Pump is in shutdown cooling
- 22 RHR Pump is in standby
Then:
- 21 RHR Pump trips
- The crew enters S2.OP-AB.RHR-0001, Loss of RHR
- Attempt to start 22 RHR Pump results in the breaker tripping free
- STA reports Time to Core Boiling is less than 15 minutes
- Field operator reports no protective relay flags are present and no obvious reason for the 4KV breaker for 22 RHR Pump to trip free, and an acrid smell is observed near the 21 RHR 4KV breaker cubicle
In accordance with OP-SA-108-106-1001, Equipment Control and Large Motor Starting Criteria, complete the following statement concerning breaker re-closure for 22 RHR Pump?
Based on the above conditions, the (1) can authorize one attempt at reclosing the breaker without an investigation ONLY during (2).
A. (1) Shift Manager (2) emergency conditions
B. (1) Plant Manager (2) emergency conditions
C. (1) Shift Manager (2) emergency conditions AND with Shift Technical Advisor concurrence
D. (1) Plant Manager (2) emergency conditions AND with Shift Technical Advisor concurrence
▶ Show Answer & Explanation
✓ A. Correct. Per OP-SA-108-106-1001 step 4.2.2, if an emergency condition exists, as determined by the SM/CRS, and a breaker fails to close, one attempt at reclosure may be made without conducting an investigation, if that piece of equipment is essential for maintaining plant stability.
✗ B. Plausible because the conditions in the stem are severe and the SRO may believe that the Plant Manager level of management is required to accept responsibility if the RHR motor is damaged.
✗ C. Plausible because the SRO may think that before reclosing the breaker to an important safety equipment that the on-shift Shift Technical Advisor should be involved in the decision process.
✗ D. Plausible because the SRO may think that before reclosing the breaker to an important safety equipment that the on-shift Shift Technical Advisor should be involved in the decision process.
Ref: OP-SA-108-106-1001 (R1) | LO: NOS05CONDOP-15, Objective 5 | Source: New | Cognitive: Comprehension/Analysis
Connections
- Related systems: RHR
- Related procedures: AB.RHR-0001 — Loss of RHR, OP-SA-108-106-1001 — Equipment Control and Large Motor Starting Criteria
- Related exam: 2023 NRC Written Exam