S2.OP-IO.ZZ-0002 — Cold Shutdown to Hot Standby
Purpose
Provides guidance for transitioning the plant from Cold Shutdown (Mode 5) to Hot Standby (Mode 3), including RCS heat up, pressurization, and system alignments.
Key Actions / Information
Exam — 2022 Q07
During RCS heat up, 2RH1 and 2RH2 (RHR Suction Isolation Valves) must be manually closed to prevent exceeding the design pressure of the RHR suction piping (450 psig). These valves do NOT auto-close on high RCS pressure — they are only interlocked to prevent opening until PT-403 and PT-405 are less than 375 psig.
Connections
- Related systems: RHR, RCS
- Related exam questions: 2022 Q07
- Related exam: 2022 NRC Written Exam