AB.SW-0004 — Loss of SW During SW Header Outage
Purpose
Provides operator actions for responding to a loss of service water when a service water header is already out of service for maintenance. Applicable during outage situations with reduced SW system lineup.
Key Actions / Information
Exam — 2020 Q53
AB.SW-0004 is for OUTAGE situations only. When a SW Bay is cleared and tagged (isolated) and a subsequent event occurs (e.g., SW pump trip + 4KV bus differential), the correct procedure entry depends on the actual impact to SW flow — AB.SW-0004 is NOT the correct entry when the plant is at power and the event does not result from the header outage itself. In the 2020 Q53 scenario, the correct entry is AB.4KV-0001 because the 1A bus differential does not affect operating SW pumps (15 and 16 SW Pumps powered from 1A Bus are already C/Ted).
Connections
- Related systems: Service Water
- Related procedures: AB.SW-0001 — Loss of SW Header Pressure, AB.SW-0005 — Loss of All Service Water
- Related exam questions: 2020 Q53
- Related exam: 2020 NRC Written Exam