JPM Sim-a — Respond to Loss of All Control Rod Drive Vent Fans
Simulator | RO/SRO | 001 A2.01 (3.1/3.7)
Location: Simulator
Time-Critical: No
Alternate Path: Yes
Estimated Time: 5 minutes
Initial Conditions:
- Unit 2 at 100% power, BOL.
- No equipment is out of service and no active Tech Specs are in effect.
Initiating Cue:
You are the Reactor Operator.
Respond to all alarms and indications.
Time-Critical: No
Alternate Path: Yes
Estimated Time: 5 minutes
Initial Conditions:
- Unit 2 at 100% power, BOL.
- No equipment is out of service and no active Tech Specs are in effect.
Initiating Cue:
You are the Reactor Operator.
Respond to all alarms and indications.
Task Standard:
1. STARTs Standby CRDM Vent Fan IAW ARP based on abnormal console indications.
2. TRIPs the Reactor IAW ARP based on no CRDM Vent Fans running.
1. STARTs Standby CRDM Vent Fan IAW ARP based on abnormal console indications.
2. TRIPs the Reactor IAW ARP based on no CRDM Vent Fans running.
▶ Show Critical Steps & Key Actions
| Step | Critical Element | Standard |
|---|---|---|
| — | Recognize abnormal console alarm | Operator reports receipt of unexpected console alarm on 21 CRD Vent Fan: AIR FLOW LO and SEQUENCE COMPLETE bezel extinguished. Operator refers to 2CC1 ARP S2.OP-AR.ZZ-0011 page 13. |
| 3.1 | Evaluate if Rod Drive Vent Fan has just been started | Operator reads step 3.1 and determines that a Vent Fan has NOT been started. Marks step N/A and continues on. |
| 3.2 * | Determine SEQUENCE COMPLETE is extinguished and swap to standby fan | Operator determines step is applicable based on SEQUENCE COMPLETE indication bezel being extinguished. Continues to perform applicable steps. |
| 3.2.A * | STOP affected Rod Drive Vent Fan | Operator depresses STOP PB for 21 Fan and verifies STOP bezel illuminates Green. |
| 3.2.B * | START standby Rod Drive Vent Fan | Operator depresses START PB for standby vent fan and verifies START bezel illuminates RED. Operator reports SEQUENCE COMPLETE bezel is illuminated and AIR FLOW LO is extinguished as expected. |
| — | ALTERNATE PATH: Both remaining running vent fans trip | Shortly after starting the standby fan, both the 23 CRD Fan (40 seconds) and 22 CRD Fan (50 seconds) trip. Operator receives AIR FLOW LO alarms for both fans. No CRDM Vent Fans are now running. |
| 3.2.C | Evaluate if standby fan cannot be started | Operator marks step as N/A based on standby fan having started (initially). |
| 3.2.D * | IF no Rod Drive Vent Fans in operation THEN TRIP the Reactor | This step was initially marked N/A when the standby fan started. It becomes applicable when all running vent fans trip. Operator TRIPs the Reactor when NO Vent Fans are in operation. JPM terminates when the reactor is tripped. |
Key Decision Point:
This is an alternate path JPM. The initial response (swap to standby fan) succeeds, but then both remaining running fans trip within seconds. The applicant must recognize that step 3.2.D — which was initially marked N/A — now becomes applicable because NO CRD Vent Fans are in operation. The ARP directs an immediate reactor trip when no CRDM Vent Fans are running, because loss of cooling to the rod drive coils could degrade the CRDM holding capability and lead to uncontrolled rod motion. The operator must trip the reactor per step 3.2.D.1. Performing EOP-TRIP-1 immediate actions is NOT required to complete this JPM.
This is an alternate path JPM. The initial response (swap to standby fan) succeeds, but then both remaining running fans trip within seconds. The applicant must recognize that step 3.2.D — which was initially marked N/A — now becomes applicable because NO CRD Vent Fans are in operation. The ARP directs an immediate reactor trip when no CRDM Vent Fans are running, because loss of cooling to the rod drive coils could degrade the CRDM holding capability and lead to uncontrolled rod motion. The operator must trip the reactor per step 3.2.D.1. Performing EOP-TRIP-1 immediate actions is NOT required to complete this JPM.
Ref: S2.OP-AR.ZZ-0011 (Rev 60), S2.OP-SO.CBV-0001 (Rev 34) | Task: 0220040101 | K/A: 001 A2.01 — Ability to predict the impacts of CRD mechanism malfunctions on plant conditions (RO 3.1 / SRO 3.7) | Source: New | View JPM PDF
Connections
- Related systems: Control Rod Drive
- Related procedures: S2.OP-AR.ZZ-0011 — Alarm Response (2CC1), S2.OP-SO.CBV-0001 — Containment Ventilation Operation
- Related EOPs: EOP-TRIP-1 — Reactor Trip or Safety Injection
- Related exam: 2019 NRC Operating Exam