Q24 — SW Nuclear Header Leak Isolation
076 SWS-A2.02 (2.7)
Given:
• The crew is performing S2.OP-AB.SW-0001 (Loss of Service Water Header Pressure)
• The leak is determined to be downstream of 21SW22 (NUCLEAR HEADER)
Which ONE of the following completes the statements below?
In accordance with S2.OP-AB.SW-0001, the crew will CLOSE 21SW22 and ENSURE _(1)_ 21SW23 and 22SW23 (TIE VALVES).
After the valve manipulations have been completed, SW cooling _(2)_ available to 21CFCU and 22CFCU.
• The crew is performing S2.OP-AB.SW-0001 (Loss of Service Water Header Pressure)
• The leak is determined to be downstream of 21SW22 (NUCLEAR HEADER)
Which ONE of the following completes the statements below?
In accordance with S2.OP-AB.SW-0001, the crew will CLOSE 21SW22 and ENSURE _(1)_ 21SW23 and 22SW23 (TIE VALVES).
After the valve manipulations have been completed, SW cooling _(2)_ available to 21CFCU and 22CFCU.
A. _(1)_ closed _(2)_ is
B. _(1)_ closed _(2)_ is NOT
C. _(1)_ open _(2)_ is
D. _(1)_ open _(2)_ is NOT
▶ Show Answer & Explanation
✓ B. Correct. For Part 1 and in accordance with S2.OP-AB.SW-0001 Attachment 4 Step 2.0, the crew will CLOSE 21SW22 and ENSURE CLOSE 21SW23 and 22SW23 (TIE VALVES). For Part 2, after the valve manipulations have been completed, SW cooling is NOT available to 21CFCU and 22CFCU.
✗ A. Incorrect but plausible. Part 1 is correct. For Part 2, the candidate could not recall the proper cooling arrangement between 21 and 22 SW headers. Additionally, 23 CFCU is the only CFCU that can be cooled by both SW headers. Either way, the candidate could then incorrectly determine that 21 and 22 CFCUs will still have SW cooling.
✗ C. Incorrect but plausible. For Part 1 and in accordance with S2.OP-AB.SW-0001 Attachment 4 Step 3.0, if the 21 SW header was leaking upstream of 21SW22, the crew would CLOSE 21SW22 and ENSURE OPEN 21SW23 and 22SW23 (TIE VALVES). Consequently, given the question stem, the candidate could incorrectly conclude that opening 21SW23 and 22SW23 is required.
✗ D. Incorrect but plausible. For Part 1 and in accordance with S2.OP-AB.SW-0001 Attachment 4 Step 3.0, if the 21 SW header was leaking upstream of 21SW22, the crew would CLOSE 21SW22 and ENSURE OPEN 21SW23 and 22SW23 (TIE VALVES). Consequently, given the question stem, the candidate could incorrectly conclude that opening 21SW23 and 22SW23 is required. Part 2 is correct.
Ref: NOS05ABSW01-03 (LOSS OF SERVICE WATER HEADER PRESSURE) | LO: 1 — Describe the operation of the SW system as applied to S1/S2.OP-AB.SW-0001; 4 — Given initial conditions, determine the appropriate AOP and describe plant response | Source: Modified Bank | Cognitive: Higher
Connections
- Related systems: Service Water, CFCUs
- Related procedures: AB.SW-0001 — Loss of SW Header Pressure
- Related exam: 2018 NRC Written Exam