JPM Sim-a — Failed Open PZR Spray Valve
Sim | RO/SRO | 010 A4.01 (3.7/3.5)
Location: Simulator
Time-Critical: No
Alternate Path: Yes
Estimated Time: 5 minutes
Initial Conditions:
- The Unit 2 is operating at 100% power with no major equipment out of service.
Initiating Cue:
- You are the Reactor Operator.
- Respond to all indications and alarms.
- Your evaluator will respond to all alarms not related to your task.
Time-Critical: No
Alternate Path: Yes
Estimated Time: 5 minutes
Initial Conditions:
- The Unit 2 is operating at 100% power with no major equipment out of service.
Initiating Cue:
- You are the Reactor Operator.
- Respond to all indications and alarms.
- Your evaluator will respond to all alarms not related to your task.
Task Standard:
Stops the RCS pressure decrease by closing 2PS1, or Trips the Reactor and stops 21 and 23 RCPs, before an Automatic SI occurs.
Stops the RCS pressure decrease by closing 2PS1, or Trips the Reactor and stops 21 and 23 RCPs, before an Automatic SI occurs.
▶ Show Critical Steps & Key Actions
| Step | Critical Element | Standard |
|---|---|---|
| Observe | Recognize PZR Pressure Channel 1 failed high | Scans control board; recognizes PZR Pressure Channel 1 is failed high. OHA D-8 (RC PRESS HI), OHA E-42 (2PR1 1/2 TRIP) annunciate. |
| MPC * | Place Master Pressure Controller in MANUAL | Depresses the MANUAL pushbutton for the Master Pressure Controller (MPC). |
| MPC * | LOWER demand on MPC to close spray valves | Depresses the PRESS INC pushbutton on the MPC to lower the demand. |
| Alt * | Recognize 2PS1 is fully OPEN after MPC demand is zeroed | With MPC demand at zero, operator reports 2PS1 remains fully OPEN. Alternate Path starts here. |
| 3.18 * | Place 2PS1 in MANUAL and CLOSE | Depresses MANUAL pushbutton for 2PS1, then depresses the CLOSE pushbutton. 2PS1 valve demand lowers and open light extinguishes. |
| 3.19 * | OPERATE Spray Valves to control pressure per Attachment 2 | Depresses CLOSE PB for 2PS1; recognizes 2PS1 demand is lowering and open light extinguished. Reports 2PS1 is CLOSED and RCS pressure is stable or rising. |
Key Decision Point:
The alternate path / discriminating step occurs when the operator lowers MPC demand to close both spray valves but 2PS1 remains fully open. The applicant must recognize the stuck-open spray valve, place 2PS1 in manual, and close it directly. If the operator enters AB.PZR-0001 first rather than taking immediate action, the procedure leads through Steps 3.3 (identify failed channel), 3.5 (MPC to Manual), 3.6 (adjust MPC), then to 3.17/3.18/3.19 for the failed spray valve. Both paths are acceptable. Alternate task standard: if RCS pressure drops to 2000 psig and continues to drop, trip the reactor and stop 21 and 23 RCPs (spray is fed from Loops 1 and 3 cold legs).
The alternate path / discriminating step occurs when the operator lowers MPC demand to close both spray valves but 2PS1 remains fully open. The applicant must recognize the stuck-open spray valve, place 2PS1 in manual, and close it directly. If the operator enters AB.PZR-0001 first rather than taking immediate action, the procedure leads through Steps 3.3 (identify failed channel), 3.5 (MPC to Manual), 3.6 (adjust MPC), then to 3.17/3.18/3.19 for the failed spray valve. Both paths are acceptable. Alternate task standard: if RCS pressure drops to 2000 psig and continues to drop, trip the reactor and stop 21 and 23 RCPs (spray is fed from Loops 1 and 3 cold legs).
Ref: S2.OP-AB.PZR-0001 (R18) | Task: 1140240401 | K/A: 010 A4.01 — Ability to predict impacts of PZR spray valve malfunction and use procedures to mitigate | Source: Modified | View JPM PDF
Connections
- Related systems: Pressurizer & PRT
- Related procedures: AB.PZR-0001 — Pressurizer Pressure Control Malfunction
- Related EOPs: EOP-TRIP-1 — Reactor Trip or Safety Injection
- Related exam: 2020 NRC Operating Exam