AB.LOCA-0001 — Shutdown LOCA
Purpose
Provides operator actions for responding to a Loss of Coolant Accident during shutdown conditions (Mode 4). Entered on any uncontrolled reduction in Pressurizer Level in Mode 4.
Key Actions / Information
Exam — 2020 Q6
Entry conditions: any uncontrolled reduction in Pressurizer Level in Mode 4. First step initiates Attachment 1, Continuous Action Summary (CAS). CAS directs: if PZR Level is <11%, then stop the operating RHR Pump aligned for Shutdown Cooling and Close 2RH1 and 2RH2 (RHR Common Suction). AB.RHR-0001 and AB.RC-0001 both redirect to AB.LOCA-0001 when in Mode 4 with uncontrolled level reduction. AB.RHR-0001 actions (isolate letdown, start SI/charging) are for Modes 5 or 6. AB.RC-0001 actions (stop RHR pump, close 21SJ49) are for Modes 1-3.
Exam — 2020 Q85
AB.LOCA-0001 applicability: used during MODE 4 or MODE 3 with the accumulators isolated. A LOCA in MODE 3 at normal operating pressure (2235 psig) with accumulators NOT isolated enters the EOP network (EOP-TRIP-1), not AB.LOCA-0001.
Exam — 2019 Q78
AB.LOCA-0001 is entered from AB.RHR-0001 CAS when in MODE 4 with RCS inventory loss (lowering PZR level and rising containment particulate monitor). The CAS directs IMMEDIATELY GO TO AB.LOCA-0001.
Connections
- Related systems: RHR
- Related procedures: AB.RHR-0001 — Loss of RHR, AB.RC-0001 — Reactor Coolant System Leak
- Related EOPs: EOP-FRTS-1 — Response to Imminent Pressurized Thermal Shock
- Related exam questions: 2019 Q78, 2020 Q6, 2020 Q85
- Related exam: 2019 NRC Written Exam, 2020 NRC Written Exam