Q29 — Charging Pump Power Supplies
004000K2.03 (3.3)
Given:
• Unit 2 is at 100% Power
• 2C Bus Differential Protection relay actuates and results in the 2C 4KV Bus de-energized.
Which ONE of the following lists the available Charging Pumps following the loss of the 2C 4KV Vital Bus?
• Unit 2 is at 100% Power
• 2C Bus Differential Protection relay actuates and results in the 2C 4KV Bus de-energized.
Which ONE of the following lists the available Charging Pumps following the loss of the 2C 4KV Vital Bus?
A. 21 Charging and 23 Charging Pumps
B. 21 Charging Pump ONLY
C. 21 Charging and 22 Charging Pumps
D. 22 Charging Pump ONLY
▶ Show Answer & Explanation
✓ A. Correct. IAW S2.OP-AB.4KV-0003, 22 CV Pump is supplied from 2C 4KV bus and if 22 CV Pump was in service the operators would place either 21 or 23 CV Pump in service.
✗ B. 21 CV Pump is available from 2B 4KV bus, but 23 CV Pump is also available from 2A 460V bus. Plausible since the operator may believe that 23 CV pump is also powered from 2C 4KV bus.
✗ C. 21 CV Pump is powered from 2B 4KV bus, but 22 CV Pump is NOT available with loss of 2C 4KV Bus.
✗ D. 22 CV Pump is NOT available from 2C 4KV bus, but 23 CV Pump is also available from 2A 460V.
Ref: S2.OP-AR.ZZ-0009(Q), Overhead Annunciators — Window J and NOS05CVCS00-17 lesson plan | LO: NOS05CVCS00-17, ELO 5.a | Source: New | Cognitive: Fundamental
Connections
- Related systems: CVCS, 4KV
- Related procedures: AB.4KV-0003 — Loss of 2C 4KV Bus, S2.OP-AR.ZZ-0009 — Overhead Annunciators Window J
- Related exam: 2020 NRC Written Exam