JPM Sim-h — Transfer 4KV Group Buses SPT to APT
Sim | RO/SRO | 062 A2.04 (3.1/3.4)
Location: Simulator
Time-Critical: No
Alternate Path: Yes
Estimated Time: 10 minutes
Initial Conditions:
- Unit 2 power ascension is in progress following refueling outage.
- Reactor power is at 20%.
- The Main Generator is connected to the grid with 190 MWe output.
- Steam Dumps are in Tavg Mode - Auto
- Rod Control is in Manual (D-104) until Group Buses are transferred
- Group Buses are currently powered from the Station Power Transformers (SPT).
Initiating Cue:
- You are the Plant Operator.
- The CRS directs you to TRANSFER all 4KV Group Buses from their respective Station Power Transformers (SPT) to the Aux Power Transformers (APT) IAW S2.OP-SO.4KV-0008, 4KV Group Buses Power Supply Transfer in the following order:
1. 2F IAW section 5.2
2. 2G IAW section 5.3
3. 2H IAW section 5.4
4. 2E IAW section 5.1
- All pre-requisites are completed SAT.
Time-Critical: No
Alternate Path: Yes
Estimated Time: 10 minutes
Initial Conditions:
- Unit 2 power ascension is in progress following refueling outage.
- Reactor power is at 20%.
- The Main Generator is connected to the grid with 190 MWe output.
- Steam Dumps are in Tavg Mode - Auto
- Rod Control is in Manual (D-104) until Group Buses are transferred
- Group Buses are currently powered from the Station Power Transformers (SPT).
Initiating Cue:
- You are the Plant Operator.
- The CRS directs you to TRANSFER all 4KV Group Buses from their respective Station Power Transformers (SPT) to the Aux Power Transformers (APT) IAW S2.OP-SO.4KV-0008, 4KV Group Buses Power Supply Transfer in the following order:
1. 2F IAW section 5.2
2. 2G IAW section 5.3
3. 2H IAW section 5.4
4. 2E IAW section 5.1
- All pre-requisites are completed SAT.
Task Standard:
1. Correctly performs the transfer of 2F 4KV Group Bus from SPT to APT IAW S2.OP-SO.4KV-0008. 2. Manually trips the Reactor IAW Alarm Response Procedure following the loss of one RCP (24 RCP).
1. Correctly performs the transfer of 2F 4KV Group Bus from SPT to APT IAW S2.OP-SO.4KV-0008. 2. Manually trips the Reactor IAW Alarm Response Procedure following the loss of one RCP (24 RCP).
▶ Show Critical Steps & Key Actions
| Step | Critical Element | Standard |
|---|---|---|
| P&L | Review Precautions and Limitations | Reviews P&Ls. Notes P&L 3.3: OHA J-39 GROUP BUS XFER FAIL will illuminate then clear on bus transfer (expected response). ARP applicable when alarm does NOT clear following bus transfer. |
| 5.2.1 | Ensure all OHA for 2 APT are clear | Checks OHA windows; determines all OHA for 2 APT are clear. |
| 5.2.2 | Ensure 2A APT voltage is 4.22 - 4.36KV | Checks 2A APT reading on 2CC3; ensures voltage is 4.22 - 4.36KV. |
| 5.2.4 * | Press Mimic Bus 2F GROUP BUS INFEED 2BFGD BREAKER pushbutton | Depresses Mimic Bus 2F pushbutton; verifies console bezel 2BFGD MIMIC BUS INTLK CLOSE SELECTION is illuminated. |
| 5.2.5 * | Press 2BFGD CLOSE pushbutton and verify transfer | Depresses 2BFGD CLOSE pushbutton. Verifies: A. 22FSD is OPEN. B. 2BFGD is CLOSED. C. 2F voltage is 4.22-4.36KV. D. MIMIC BUS INTLK CLOSE SELECTION is extinguished. |
| 5.3.4 * | Press Mimic Bus 2G GROUP BUS INFEED 2BGGD BREAKER pushbutton | Depresses Mimic Bus 2G pushbutton; verifies console bezel 2BGGD MIMIC BUS INTLK CLOSE SELECTION is illuminated. |
| 5.3.5 * | 2G 4KV Group Bus fails to transfer — loss of 24 RCP | Presses 2BGGD CLOSE pushbutton. 2G bus does NOT transfer — bus de-energizes. Multiple OHAs annunciate: J-8 (2G 4KV GRP BUS DIFF/OVRLD), J-38 (4KV GRP BUS UNDRVOLT), J-39 (4KV GRP BUS XFER FAIL), D-31 (24 RCP BKR OPEN/FLO LO). 24 RCP trips due to loss of bus. |
| ARP * | Respond to OHA ARPs — Trip the Reactor | Identifies from OHA J-38 or D-31 ARP: IF ANY RCP Trips, THEN TRIP Reactor, GO TO 2-EOP-TRIP-1. Manually trips the reactor. |
Key Decision Point:
Step 5.3.5 is the alternate path / discriminating step. The 2F Group Bus transfers successfully, but when attempting to transfer the 2G Group Bus from SPT to APT, the bus fails to transfer and de-energizes. This causes the loss of 24 RCP (powered from 2G bus). Multiple OHA alarms annunciate simultaneously. The applicant must recognize the significance of losing an RCP and use the Alarm Response Procedures (J-39 directs to J-38; J-38/D-31 both direct: IF ANY RCP Trips, THEN TRIP Reactor and GO TO EOP-TRIP-1) to determine that a manual reactor trip is required. Key P&L knowledge: P&L 3.3 warned that J-39 alarm illuminating is expected during transfer, but if it does NOT clear, the ARP response applies. The applicant must recognize the difference between the expected transient alarm and the actual failure.
Step 5.3.5 is the alternate path / discriminating step. The 2F Group Bus transfers successfully, but when attempting to transfer the 2G Group Bus from SPT to APT, the bus fails to transfer and de-energizes. This causes the loss of 24 RCP (powered from 2G bus). Multiple OHA alarms annunciate simultaneously. The applicant must recognize the significance of losing an RCP and use the Alarm Response Procedures (J-39 directs to J-38; J-38/D-31 both direct: IF ANY RCP Trips, THEN TRIP Reactor and GO TO EOP-TRIP-1) to determine that a manual reactor trip is required. Key P&L knowledge: P&L 3.3 warned that J-39 alarm illuminating is expected during transfer, but if it does NOT clear, the ARP response applies. The applicant must recognize the difference between the expected transient alarm and the actual failure.
Ref: S2.OP-SO.4KV-0008 (R13), S2.OP-AR.ZZ-0009 (R28) | Task: N0620110101 | K/A: 062 A2.04 — Ability to predict impacts of bus failure on AC distribution and use procedures to mitigate | Source: Bank | View JPM PDF
Connections
- Related systems: 4KV
- Related procedures: S2.OP-SO.4KV-0008 — 4KV Group Buses Power Supply Transfer, S2.OP-AR.ZZ-0009 — Overhead Annunciators Window J
- Related EOPs: EOP-TRIP-1 — Reactor Trip or Safety Injection
- Related exam: 2020 NRC Operating Exam