AB.RHR-0002 — Loss of RHR at Reduced Inventory
Purpose
Provides operator actions for responding to a loss of Residual Heat Removal while at reduced RCS inventory (Water Elevation 101 feet or less).
Key Actions / Information
Exam — 2019 Q87
AB.RHR-0002 entry criteria: applies when RCS is at Water Elevation of 101 feet or LESS. At Water Elevation 103.5 feet, the plant is NOT at reduced inventory — AB.RHR-0001 (Loss of RHR) applies instead. Trap: with empty PZR and RCS at 103.5 feet, candidates may incorrectly select AB.RHR-0002 because the PZR is empty. The determining factor is RCS Water Elevation, not PZR level.
Exam — 2018 Q53
AB.RHR-0002 CAS: "IF AT ANY TIME, a Charging OR SI pump cannot be aligned and started to make up to the RCS, THEN the crew will ESTABLISH RWST Gravity Feed to RCS level > 97.5 feet." The logic is OR — either a charging pump OR an SI pump must be available. If NEITHER can be aligned, establish RWST gravity feed. Trap: AND logic (both must fail) is incorrect. Only one pump type needs to fail to be unable to make up for the CAS to direct RWST gravity feed.
Connections
- Related systems: RHR, ECCS, CVCS
- Related abnormals: AB.RHR-0001 — Loss of RHR
- Related exam questions: 2018 Q53, 2019 Q87
- Related exam: 2018 NRC Written Exam, 2019 NRC Written Exam