Q50 — CFCU SW Flow in High vs Low Speed
T2G1 076 A1.03 (3.3)
Given:
• Salem Unit 1 is at 100% power
• Three (3) Service Water (SW) Pumps are in service
• Four (4) CFCUs are running in HIGH speed
• SW header pressures are 108 psig
Then:
• The PO is directed to place one running CFCU in LOW speed for surveillance testing
Which of the following completes the statement concerning the response on the Service Water System (assume three SW pumps remain running at all times)?
As compared to the SW header pressure while operating in HIGH speed, the SW header pressure will be (1) when operating in LOW speed and SW flow rate through the CFCU will be (2).
• Salem Unit 1 is at 100% power
• Three (3) Service Water (SW) Pumps are in service
• Four (4) CFCUs are running in HIGH speed
• SW header pressures are 108 psig
Then:
• The PO is directed to place one running CFCU in LOW speed for surveillance testing
Which of the following completes the statement concerning the response on the Service Water System (assume three SW pumps remain running at all times)?
As compared to the SW header pressure while operating in HIGH speed, the SW header pressure will be (1) when operating in LOW speed and SW flow rate through the CFCU will be (2).
A. (1) lower (2) the same
B. (1) lower (2) higher
C. (1) the same (2) the same
D. (1) the same (2) higher
▶ Show Answer & Explanation
✓ C. Correct. The SW flow rates through the CFCUs in High and Low speed are the same, therefore, the SW header pressure will also be the same when operating in High and Low speed.
✗ A. Incorrect. Plausible because the SW flow through the CFCUs is the same for high or low speed operation. Correct in that the SW header will be relatively the same.
✗ B. Incorrect. Plausible because prior operation of the CFCUs in low speed use to have a higher flow rate. Incorrect in that orifices have been installed to maintain constant flow rates in either speed.
✗ D. Incorrect. Plausible because prior operation of the CFCUs in low speed use to have a higher flow rate. Incorrect in that orifices have been installed to maintain constant flow rates in either speed.
Ref: NOS05CONTMT-17 | Source: New | Cognitive: Comprehension/Analysis
K/A: 076 A1.03 — Ability to predict and/or monitor changes in parameters associated with operation of the Service Water System: SWS header pressure
K/A: 076 A1.03 — Ability to predict and/or monitor changes in parameters associated with operation of the Service Water System: SWS header pressure
Connections
- Related systems: Service Water, CFCUs
- Related procedures:
- Related exam: 2023 NRC Written Exam