SALEM
SALEM STUDY SYSTEM
Systems > RVLIS

RVLIS

⚠️ DRAFT

RVLIS

Function

Reactor Vessel Level Indication System provides indication of reactor vessel water level during post-accident conditions.

Exam — 2022 Q84
RVLIS Train B requires 2PT-405 (Wide Range RCS Pressure) as an input. If 2PT-405 fails AND Train A is out of service for maintenance, both trains of RVLIS are unavailable → enter EOP-TRIP-6 (Natural Circulation Cooldown without RVLIS) instead of EOP-TRIP-5 (with RVLIS). In EOP-TRIP-6, maximum RCS cooldown rate is 50F/hr when T-Hots >500F, increasing to 100F/hr when T-Hots <450F. 100F/hr is only allowed below 450F T-Hot — at 540F T-Hot, the maximum is 50F/hr.
Exam — 2020 Q16
Dynamic range RVLIS would NOT be valid during a small break LOCA because RCPs would have been stopped IAW CAS at < 1350 psig. Dynamic range requires RCPs running; with RCPs stopped, only full range RVLIS is available.

RVLIS Ranges and CFST Thresholds

Exam — 2020 Q24
Core Cooling Red Path (no RCPs running): requires five (5) hottest CETs > 700°F AND RVLIS Full Range ≤ 39%. RVLIS Upper Range is NOT applicable for core cooling status — it only provides indication from the hot leg piping connection to the top of the reactor vessel. Purple Path (degraded core cooling with RCPs running): RVLIS Dynamic Range ≤ 44%. CET-based inadequate core cooling Red Path: five (5) CETs > 1200°F (not three).
Exam — 2020 Q84
Natural circulation rapid cooldown rate limits depend on RVLIS availability: with RVLIS: 100°F/hr for the entire cooldown. Without RVLIS: initial cooldown to 500°F limited to < 50°F/hr, then < 100°F/hr afterwards. RVLIS availability determines which EOP is used for rapid cooldown.
Exam — 2019 Q47
2PT-403 (RCS Narrow Range Pressure) and 2PT-405 (RCS Wide Range Pressure) provide input to both the Pressurizer Overpressure Protection System (POPS) and to the RVLIS Electronics Cabinets. Both 2PT-403 and 2PT-405 are credited as accident monitoring instrumentation per LCO 3.3.3.7. Trap: POPS is not their only function — they also feed RVLIS. Loss of 2PT-405 affects RVLIS Train B availability (confirmed by 2022 Q84).
Exam — 2019 Q85
RVLIS Train A power supply: 2B Vital Instrument Bus powers the Train A Microprocessor Panel. Loop 22 THOT also provides input to Train A RVLIS. Loss of 2B VIB makes only Train A inoperable — Train B is unaffected. With Train B available, RVLIS is available and EOP-TRIP-6 (with RVLIS) applies for natural circulation rapid cooldown, not EOP-TRIP-5.

Connections