AB.460-0001 — Loss of 2A 460V Bus
⚠️ DRAFT — Reconstructed from exam materials
Purpose
Provides guidance for responding to a loss of the 2A 460V and/or 230V vital bus on Salem Unit 2.
Key Information
Major Loads on 2A 460V Bus
- 23 Charging Pump
Major Loads on 2A 230V Bus
- 282 125VDC Battery Charger
- Emergency power to IRPI indications
- 2A EDG Starting Air Compressors (21A and 21B)
Major Loads on 2B 230V Bus
- 281 125VDC Battery Charger
- Normal power to IRPI indications
Key Actions
- Start a centrifugal charging pump and restore PZR level
- Re-establish letdown
Exam — 2023 Q45
An overcurrent fault on the 2A 460V MCC causes feeder breaker 2A4D to trip open, de-energizing both the 2A 460V and 230V MCCs. This results in loss of 23 charging pump and letdown isolation. Per S2.OP-AB.460-0001, start a centrifugal charging pump and re-establish letdown.
Connections
- Related systems: 500KV, CVCS, DC Power
- Related exam questions: 2023 Q45
- Related exam: 2023 NRC Written Exam