Q15 — EOP-LOCA-5 CS Pumps Required
026 CSS-G2.1.25 (3.9)
Given:
REFERENCE PROVIDED
• The crew is performing 2-EOP-LOCA-5 (LOSS OF EMERGENCY RECIRCULATION) Step 6
• 2B 4KV Vital Bus is de-energized and locked out
• Containment Sump Level is 55%
• 21SJ44 (SUMP VALVE) and 22SJ44 (SUMP VALVE) are BOTH closed
• RWST Level is 10 Feet and lowering
• Containment Pressure is 19 psig
In accordance with 2-EOP-LOCA-5, which ONE of the following completes the statement below?
The crew's NEXT action will be to ___
REFERENCE PROVIDED
• The crew is performing 2-EOP-LOCA-5 (LOSS OF EMERGENCY RECIRCULATION) Step 6
• 2B 4KV Vital Bus is de-energized and locked out
• Containment Sump Level is 55%
• 21SJ44 (SUMP VALVE) and 22SJ44 (SUMP VALVE) are BOTH closed
• RWST Level is 10 Feet and lowering
• Containment Pressure is 19 psig
In accordance with 2-EOP-LOCA-5, which ONE of the following completes the statement below?
The crew's NEXT action will be to ___
A. add makeup to the RWST
B. stop BOTH Containment Spray Pumps
C. stop ONLY ONE Containment Spray Pump
D. IMMEDIATELY RETURN TO PROCEDURE IN EFFECT
▶ Show Answer & Explanation
✓ B. Correct. IAW 2-EOP-LOCA-5 Step 6 Table B, NO TRAINS of Emergency Recirculation are available. Consequently, the candidate must analyze 2-EOP-LOCA-5 Steps 6.1 through 9 and Table C to determine if any of the CS Pumps are required to be stopped. Based on Table C and Step 9 with Containment Pressure = 19 psig, RWST Level equal to 10 feet, and only 3 CFCUs running in slow speed (with 2B 4KV Vital Bus de-energized and locked out, ONLY 3 CFCUs are running in slow speed), 0 CS Pumps are required. Consequently, the crew will stop BOTH Containment Spray Pumps.
✗ A. The candidate could correctly analyze Table B and then incorrectly analyze Table C to determine that both CS Spray Pumps are required. This would then cause the candidate to incorrectly conclude that the crew's NEXT action will be to add makeup to the RWST (2-EOP-LOCA-5 Step 10).
✗ C. The candidate could correctly analyze Table B and then incorrectly analyze Table C to determine that only one CS Spray Pump is required. This would then cause the candidate to incorrectly conclude that the crew's NEXT action will be to stop ONLY ONE Containment Spray Pump (2-EOP-LOCA-5 Step 9).
✗ D. The candidate could incorrectly analyze Table B. This would then cause the candidate to incorrectly conclude that the crew's NEXT action will be to IMMEDIATELY RETURN TO PROCEDURE IN EFFECT (2-EOP-LOCA-5 Step 6).
Ref: 2-EOP-LOCA-5 (Loss of Emergency Recirculation) | LO: NOS05LOCA05-04 LO 7 — Determine a discrete path through the EOP for Loss of Emergency Recirculation | Source: New | Cognitive: Higher
Connections
- Related systems: Containment Spray, CFCUs, ECCS, 4KV
- Related EOPs: EOP-LOCA-5 — Loss of Emergency Coolant Recirculation
- Related exam: 2019 NRC Written Exam