Q77 — Loss of Charging Pump Tech Spec Entries
000022G2.2.22 (4.7)
Given:
• Unit 2 is at 100% Power.
• 21 Charging Pump is in service.
• 22 and 23 Charging Pumps are Operable.
Subsequently, the following sequence of events occurs:
• 21 Charging Pump trips due to a breaker malfunction.
• The CRS enters S2.OP-AB.CVC-0001, Loss of Charging, and starts 23 Charging Pump.
Based on the above conditions complete the following statements:
(1) The CRS will enter Technical Specification LCO(s) _(1)_.
(2) Assuming that 21 Charging Pump remains INOPERABLE for the next four (4) days, the CRS will place the Unit in _(2)_.
Note: 3.1.2.2, Reactivity Control Systems – Boration Flow Paths
3.1.2.4, Reactivity Control Systems – Charging Pumps
3.5.2, ECCS Subsystems
• Unit 2 is at 100% Power.
• 21 Charging Pump is in service.
• 22 and 23 Charging Pumps are Operable.
Subsequently, the following sequence of events occurs:
• 21 Charging Pump trips due to a breaker malfunction.
• The CRS enters S2.OP-AB.CVC-0001, Loss of Charging, and starts 23 Charging Pump.
Based on the above conditions complete the following statements:
(1) The CRS will enter Technical Specification LCO(s) _(1)_.
(2) Assuming that 21 Charging Pump remains INOPERABLE for the next four (4) days, the CRS will place the Unit in _(2)_.
Note: 3.1.2.2, Reactivity Control Systems – Boration Flow Paths
3.1.2.4, Reactivity Control Systems – Charging Pumps
3.5.2, ECCS Subsystems
A. _(1)_ 3.1.2.2 for not having the required boration flowpath operable, 3.1.2.4 for not having the required Charging Pumps operable, and 3.5.2 for not having the required ECCS subsystems operable.
_(2)_ MODE 3 and borated to at least 1 % delta k/k within 78 hours from the pump trip.
_(2)_ MODE 3 and borated to at least 1 % delta k/k within 78 hours from the pump trip.
B. _(1)_ 3.1.2.2 for not having the required boration flowpath operable, 3.1.2.4 for not having the required Charging Pumps operable, and 3.5.2 for not having the required ECCS subsystems operable.
_(2)_ MODE 4 within 84 hours from the pump trip.
_(2)_ MODE 4 within 84 hours from the pump trip.
C. _(1)_ 3.5.2 ONLY for not having the required ECCS subsystems operable.
_(2)_ MODE 4 within 84 hours from the pump trip.
_(2)_ MODE 4 within 84 hours from the pump trip.
D. _(1)_ 3.5.2 ONLY for not having the required ECCS subsystems operable.
_(2)_ MODE 3 and borated to at least 1 % delta k/k within 78 hours from the pump trip.
_(2)_ MODE 3 and borated to at least 1 % delta k/k within 78 hours from the pump trip.
▶ Show Answer & Explanation
✓ C. Correct. Because the reactivity technical specifications are still met, technical specification 3.5.2 (ECCS) is the only applicable tech spec entry. If the 21 Charging Pump is not restored to operable status within 72 hours, the action is to place the unit in Hot Shutdown within the next 12 hours.
✗ A. The first part is plausible because the candidate may believe that the loss of one charging pump causes entry into both the boration flow path and charging pumps reactivity technical specifications. Incorrect as two boration flow paths still exist and two charging pumps are still operable (23 Charging Pump counts for reactivity addition capability). Tech Spec entry into 3.5.2 (ECCS) is correct. The second part is plausible because this is the action for loss of two boration flow paths.
✗ B. The first part is plausible because the candidate may believe that the loss of one charging pump causes entry into both the boration flow path and charging pumps reactivity technical specifications. Incorrect as two boration flow paths still exist and two charging pumps are still operable (23 Charging Pump counts for reactivity addition capability). Tech Spec entry into 3.5.2 (ECCS) is correct. The second part is correct.
✗ D. The first part is correct. The second part is plausible because this is the action for loss of two boration flow paths.
Ref: S2.OP-AB.CVC-0001(Q), Loss of Charging | LO: N/A | Source: Bank – Salem 2015 NRC Exam – SRO Q2 | Cognitive: Comprehension | SRO-Only: Requires knowledge of content & basis of Boration Flow Path and ECCS Technical Specifications
Connections
- Related systems: CVCS, ECCS
- Related tech specs: TS 3/4.1.2 — Boration Systems, TS 3/4.5 — ECCS
- Related procedures: AB.CVC-0001 — Loss of Charging
- Related exam: 2020 NRC Written Exam