JPM Sim-g — Respond to Loss of 2A 4KV Vital Bus
Sim | RO | 062 A2.04 (3.1/3.4)
Location: Simulator
Time-Critical: No
Alternate Path: Yes
Estimated Time: 10 minutes
Initial Conditions:
- 100% power, BOL.
Initiating Cue:
- You are the Reactor Operator. Respond to all indications and alarms.
Time-Critical: No
Alternate Path: Yes
Estimated Time: 10 minutes
Initial Conditions:
- 100% power, BOL.
Initiating Cue:
- You are the Reactor Operator. Respond to all indications and alarms.
Task Standard:
Operator closes the 2CV55 and starts 21 Charging Pump. Upon receiving indications that 21 Charging Pump trips; starts 22 Charging Pump.
Operator closes the 2CV55 and starts 21 Charging Pump. Upon receiving indications that 21 Charging Pump trips; starts 22 Charging Pump.
▶ Show Critical Steps & Key Actions
| Step | Critical Element | Standard |
|---|---|---|
| CUE | Loss of 2A 4KV Vital Bus alarms and indications | Acknowledges alarms and indications of vital bus loss. Enters S2.OP-AB.4KV-0001 based on assessment of OHAs or alarm response procedures. |
| 3.1 | Initiate Attachment 1, Continuous Action Summary | Reviews CAS and determines no actions required at this time. |
| 3.2 | Initiate Diesel Generator running checks | Identifies that A EDG has started. Notifies CRS that the A EDG needs running checks completed. |
| 3.3 | If 23 Charging Pump was providing to Unit 1, notify Unit 1 NCO | Identifies 23 CV pump was in operation to Unit 2 RCS. |
| 3.4 * | Was 23 Charging Pump providing Seal Injection and Charging Flow to Unit 2 | Operator answers YES and continues to step 3.5. |
| 3.5 * | CLOSE 2CV55 | Operator closes 2CV55. (Note: valve has a long stroke time, approximately two minutes.) |
| 3.6 * | START 21 Charging Pump | Starts 21 Charging Pump by depressing pushbutton. Subsequently identifies that the pump has tripped and acknowledges flashing stop pushbutton. |
| 3.7 * | Is 21 Charging Pump running — NO | Operator answers NO and continues to step 3.8. |
| 3.8 * | START 22 Charging Pump | Operator starts 22 Charging Pump by depressing pushbutton. |
Key Decision Point:
Steps 3.7/3.8 are the alternate path / discriminating steps. After the loss of the 2A 4KV Vital Bus, the 23 Charging Pump (which was providing seal injection and charging flow to Unit 2) is lost. The operator closes 2CV55 and attempts to start 21 Charging Pump, but it trips on start. The applicant must recognize that 21 Charging Pump has failed (answer step 3.7 as NO) and immediately start 22 Charging Pump per step 3.8 to restore RCP seal injection and charging flow.
Steps 3.7/3.8 are the alternate path / discriminating steps. After the loss of the 2A 4KV Vital Bus, the 23 Charging Pump (which was providing seal injection and charging flow to Unit 2) is lost. The operator closes 2CV55 and attempts to start 21 Charging Pump, but it trips on start. The applicant must recognize that 21 Charging Pump has failed (answer step 3.7 as NO) and immediately start 22 Charging Pump per step 3.8 to restore RCP seal injection and charging flow.
Ref: S2.OP-AB.4KV-0001 (Rev 11) | Task: N1140050401 | K/A: 062 A2.04 — Ability to predict the impacts of loss of AC electrical distribution on AC electrical distribution (3.1/3.4) | Safety Fn: 6 | Source: New | View JPM PDF
Connections
- Related procedures: AB.4KV-0001 — Loss of 4KV Vital Bus
- Related systems: 4KV, CVCS, EDGs
- Related exam: 2022 NRC Operating Exam