Q59 — SFP Heat Exchanger Tube Rupture
T2G2 033 K6.11 (3.4)
Given:
- Salem Unit 1 is in MODE 5
- Spent Fuel Pool level is 128' 5"
- Spent Fuel Pool boron concentration is 2300 ppm
Then:
- A tube inside the in-service Spent Fuel Pool Heat Exchanger ruptures
Which of the following completes both statements?
1. Level in the Spent Fuel Pool will (1).
2. The Spent Fuel Pool boron concentration will require adjustments from a (2) water source.
- Salem Unit 1 is in MODE 5
- Spent Fuel Pool level is 128' 5"
- Spent Fuel Pool boron concentration is 2300 ppm
Then:
- A tube inside the in-service Spent Fuel Pool Heat Exchanger ruptures
Which of the following completes both statements?
1. Level in the Spent Fuel Pool will (1).
2. The Spent Fuel Pool boron concentration will require adjustments from a (2) water source.
A. (1) rise (2) non-borated
B. (1) rise (2) borated
C. (1) lower (2) borated
D. (1) lower (2) non-borated
▶ Show Answer & Explanation
✓ B. Correct. Per S2.OP-AB.CC-0001, a leak in the SFP HX will result in the out leakage of CCW into the SFP system resulting in the CCW Surge Tank level lowering and the SFP level rising. The non-borated CCW water will reduce the boron concentration of the SFP. If boron concentration lowers below TS then the crew will need to add borated water into the SFP to raise the boron concentration. Note: SFP low and high level alarms 128' 2" and 129' 2".
✗ A. Plausible because the SFP level will rise. Incorrect in that CCW is a non-borated water source and will reduce the boron concentration.
✗ C. Plausible because the operator may incorrectly recall that the SFP HX will leak into the CCW system. Incorrect per S1.OP-AB.CC-0001, SFP HX will be out leakage from CCW.
✗ D. Plausible because the operator may incorrectly recall that the SFP HX will leak into the CCW system. Incorrect per S1.OP-AB.CC-0001, SFP HX will be out leakage from CCW and that the boron concentration will reduce requiring addition from a borated source.
Ref: S1.OP-IO.ZZ-0010 (R30), TS 3.9.11 | LO: NOS05SFP000-12, Objective 5.e — Describe the function of the following components and how their abnormal operation affects the Spent Fuel Pool Cooling System: Spent Fuel Pool Heat Exchanger | Source: Bank — Turkey Point 2016 NRC RO61 | Cognitive: Comprehension/Analysis
Connections
- Related systems: CCW
- Related procedures: AB.CC-0001 — Loss of Component Cooling Water
- Related exam: 2023 NRC Written Exam