SALEM
SALEM STUDY SYSTEM
EOPs > EOP-FRCI-3 — Response to Void in Reactor Vessel

EOP-FRCI-3 — Response to Void in Reactor Vessel

⚠️ DRAFT

EOP-FRCI-3 — Response to Void in Reactor Vessel

Purpose

Provides guidance for responding to a void (steam bubble) in the reactor vessel upper head, entered when CFST indicates a YELLOW path on Coolant Inventory. Directs actions to vent hydrogen from the RCS while maintaining containment hydrogen concentration below the flammability limit.

Key Actions / Information

JPM — 2022 RO-A1
Attachment 1 determines maximum venting time to prevent exceeding 3.0% containment hydrogen concentration limit. Calculation steps: (1) convert containment temperature to absolute (add 460), (2) calculate Tfact = 492/Tabs, (3) calculate air volume at STP = 2.62E06 x Tfact, (4) calculate max vent volume M = (3.0% - H) x V / 100%, (5) read hydrogen flow rate from Figure 1 at RCS pressure, (6) Tv = M/F. Given 140F containment, 2.3% H2, 1600 psig RCS: max vent time = 4.5 minutes (4.2-4.7 acceptable band).
JPM — 2019 RO-A1
Same Attachment 1 calculation as 2022 but with different revision formula and input values. Rev 30 uses V = 1.28E09 / Tabs (versus Rev 40 which uses V = 2.62E06 x Tfact). Given 140 F containment, 1.8% H2, 1200 psig RCS: Tabs = 600 R, V = 2.13E06 ft3, M = 25560 ft3, flow rate from Figure 1 = 2500 cfm, max vent time = 10.2 minutes (9.2 - 11.2 acceptable band). The wider acceptable band reflects rounding variations across intermediate steps.
Exam — 2018 Q76
Step 2 — transition check: if BOTH SI Pumps are running (Safety Injection has occurred), then the crew will immediately return to procedure in effect (e.g., EOP-LOCA-1). During a PZR Vapor Space LOCA, PZR level is NOT a valid indication of RCS inventory. Trap: during all other LOCAs, PZR level IS a valid indication of RCS inventory. The PZR Vapor Space LOCA is unique because the break IS in the pressurizer — level indication is unreliable. Also: Step 3 (establish normal charging) is NOT reached when both SI pumps are running because Step 2 directs return to procedure in effect first.

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