SALEM
SALEM STUDY SYSTEM
EOPs > EOP-LOCA-6 — LOCA Outside Containment

EOP-LOCA-6 — LOCA Outside Containment

⚠️ DRAFT

EOP-LOCA-6 — LOCA Outside Containment

Purpose

Provides operator actions for isolating a loss of coolant accident occurring outside the containment building.

Key Actions / Information

Exam — 2023 Q16
Step 2 — close 2SJ135 Cold Leg Discharge Valve to isolate an SI pump cold leg leak. SI pump flow (not pressure) is the correct indicator when RCS pressure is above SI pump shutoff head (1520 psig). Note: SJ49 valves isolate RHR cold legs, not SI cold legs.
Exam — 2022 Q18
SJ49s (Cold Leg Isolation Valves) are normally open and NOT closed by SI or Phase A signals. To close: place affected SJ49 CMC switch on 2RP4 to VALVE OPERABLE only (no Phase A reset needed). After valve closure, monitor RCS PRESSURE (not PZR level) to determine if leak isolation was successful.
Exam — 2020 Q16
After performing individual flowpath isolations in LOCA-6, the procedure specifically asks "Is RCS Pressure Rising" to verify successful leak isolation. Per the bases, if the break is isolated, a significant RCS pressure increase will occur due to ECCS flow filling up the RCS with break flow stopped. Do not confuse with PZR level rising, RVLIS rising, or subcooling > 0F — those are NOT the specific check in LOCA-6. Also note: dynamic range RVLIS would not be valid during a small break LOCA because RCPs would have been stopped IAW CAS at < 1350 psig.
Exam — 2020 Q25
LOCA outside containment recognition during SI termination (EOP-TRIP-3): key alarm indications include A-6 (RMS HI RAD OR TRBL) due to 2R41D (Plant Vent), C-34 (22 RHR SUMP OVRFLO), and A-41 (AUX ALM SYS PRINTER) due to 23 and 24 RHR sump pump starts. Combined with PZR level off-scale low (unable to be recovered) and loss of subcooling, the crew recognizes the TRIP-3 CAS is not met → goes to EOP-LOCA-1 → transitions to EOP-LOCA-6. No direct transition from TRIP-3 to LOCA-6 exists.
Exam — 2019 Q63
Leak isolation strategy: the crew is MOST concerned with the piping connecting the RHR System to the RCS, since RHR piping is only rated to 600 psig (compared to RCS piping rated to 2500 psig). Successful leak isolation is confirmed by monitoring rising RCS pressure. Do not confuse with Pressurizer level rising — LOCA-6 specifically monitors RCS pressure, not PZR level, as the determination of successful isolation. SI piping is also outside containment but is higher rated than RHR piping, so RHR is the primary concern.
Exam — 2019 Q81
Transition from LOCA-6: if the crew is NOT successful in finding and isolating the leak, the crew will transition to EOP-LOCA-5 (LOSS OF EMERGENCY RECIRCULATION). If the crew successfully isolates the leak, transition is to EOP-LOCA-1 (not LOCA-2 or AB.LOCA-0001).
Scenario — 2019 #1
RHR intersystem RCS leak on 22 RHR Heat Exchanger during EOP-TRIP-2. Crew recognizes LOCA outside containment from 2R41D Plant Vent radiation monitor in alarm, 22 RHR sump pump starts/overflow, and lowering PZR level/pressure. In LOCA-6, crew isolates leak by closing 22SJ49 (Cold Leg Injection isolation for 22 RHR). RCS pressure confirmed rising after isolation. CT-32: Isolate LOCA outside containment before transition out of EOP-LOCA-6. After isolation, crew transitions to EOP-LOCA-1 and determines SI termination criteria met.
Exam — 2018 Q63
Step 2 — RHR discharge cross-connect isolation: the crew WILL close 11RH19 and 12RH19 (RHR Discharge X-CONN Valves) to separate the 11 and 12 RHR discharge lines, enhancing leak isolation diagnostics. Successful leak isolation is confirmed by monitoring rising RCS Pressure (not PZR level). Trap: PZR level would also rise after successful isolation (ECCS filling the RCS), but LOCA-6 specifically monitors RCS pressure as the success indicator.

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