EOP-TRIP-5 — Natural Circulation Cooldown With RVLIS
Warning: DRAFT — Reconstructed from exam materials. Note: The 2020 exam labels EOP-TRIP-5 as “Natural Circulation Rapid Cooldown without RVLIS” and TRIP-6 as “with RVLIS”, while the 2022 exam labels TRIP-5 as “with RVLIS” and TRIP-6 as “without RVLIS”. The procedure numbering may reflect a revision change. The cooldown rate values are consistent across both exams.
Purpose
Provides guidance for natural circulation cooldown with steam voids in the vessel when RVLIS IS available. Entered from EOP-TRIP-4 when RVLIS is available and rapid cooldown/depressurization is required.
Key Actions / Information
Exam — 2022 Q84
Maximum allowable RCS cooldown rate with RVLIS available: 100°F/hr for the entire cooldown. Without RVLIS (EOP-TRIP-6), the rate is more restrictive: 50°F/hr when T-Hots > 500°F, then 100°F/hr when T-Hots < 450°F.
Exam — 2020 Q84
Natural circulation rapid cooldown with RVLIS: maximum rate is 100°F/hr for the entire cooldown. Without RVLIS: initial cooldown to 500°F is limited to < 50°F/hr, then < 100°F/hr afterwards.
Connections
- Related systems: RVLIS, RCS
- Related EOPs: EOP-TRIP-4 — Natural Circulation, EOP-TRIP-6 — Natural Circulation Cooldown Without RVLIS
- Related exam questions: 2022 Q84, 2020 Q84
- Related exam: 2022 NRC Written Exam, 2020 NRC Written Exam