05000395/LER-2005-002
| Docket Number | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3952005002R01 - NRC Website | |
PLANT IDENTIFICATION
Westinghouse - Pressurized Water Reactor
EOUIPMENT IDENTIFICATION
N/A
IDENTIFICATION OF EVENT
During start-up from Refueling Outage (RF) 15, VCSNS was escalated in power from Mode 4 to Mode 3 on May 28, 2005 at 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br />. At 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />, during Operator walkdown of the Main Control Board (MCB), the oncoming nightshift crew discovered the "A" Motor Driven Emergency Feedwater Pump (MDEFP) switch was in Pull-To-Lock (PTL). VCSNS Technical Specifications (TS) 3.7.1.2 requires that all Emergency Feedwater (EFW) Pumps be operable in Modes 1, 2, and 3.
EVENT DATE
May 28, 2005 Condition Evaluation Report CER 05-2300 was generated to address investigation, cause, and corrective actions associated with this event.
REPORT DATE
July 27, 2005 Original submittal April 6, 2006 Revision 1
CONDITIONS PRIOR TO EVENT
Mode 3, 0% Power — Refueling Outage 15
DESCRIPTION OF EVENT
On May 28, 2005 at 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> during Operator walkdown of the MCB, the oncoming nightshift crew discovered the "A" Motor Driven Emergency Feedwater Pump (MDEFP) switch was in Pull-To-Lock (PTL) with the plant in Mode 3.
South Carolina Electric & Gas Company (SCE&G) was performing start-up of V. C. Summer Nuclear Station (VCSNS) following the recent refueling outage. The plant escalated to Mode 3 on 5/28/05 at 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br />. In Mode 3 the Emergency Feedwater (EFW) pumps are required to be Operable. The "A" MDEFP switch was apparently placed in Pull-To-Lock (PTL) following extensive retesting of the EFW pumps over the previous 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The last test occurred at approximately 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> on 5/28/05. At 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br />, entry into Mode 3 was declared. With the "A" MIDEFP inoperable, the plant was in a condition prohibited by VCSNS Technical Specification (TS) 3.7.1.2 and subject to report in accordance with 10CFR50.73(a)(2)(i)(B).
CAUSE OF EVENT
This event is attributed to procedural weaknesses in conducting multiple tasks concurrently for plant startup influenced by insufficient administrative controls. Also, an additional contributing factor was that the Bypass Inopera'ple Status Indication (BISI) program did not provide a back up indication that the EFW system was out of alignment due to the Integrated Plant Computer System (IPCS) computer being upgraded and not fully functional at the time of the event.
ANALYSIS OF EVENT
The plant escalated to Mode 3 on 5/28/05 at 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br />. In Mode 3 the EFW pumps are required to be Operable.
The switch for "A" MDEFP was apparently placed in Pull-To-Lock (PTL) following extensive retesting of the EFW pumps over the previous 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The last test occurred at approximately 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> on 5/28/05. At 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br />, entry into Mode 3 was declared. With the "A" MDEFP inoperable, the plant was in a condition prohibited by VCSNS Technical Specification (TS) 3.7.1.2.
Upon discovery at 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />, the "A" MDEFP switch was placed in Normal-After-Stop and the pump was declared Operable. There was no adverse impact from this event. The system remained functional at all times. Had the "A" MDEFP been required to start, numerous Main Control Board (MCB) alarms would have alerted the operators to the need for the pump and the fact that the pump was not in operation.
The "A" MDEFP had been tested many times over the previous 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and left in PTL. Since testing occurred many times, the pump was left in PTL to facilitate the next test. Due to the multiple tasks being conducted concurrently for plant startup, the "A" MDEFP was not restored from PTL when the mode escalation occurred.
An additional contributing factor to the human error that failed to recognize the PTL on the "A" MDEFP was that the Integrated Plant Computer System (IPCS) computer was replaced this outage. Since the IPCS was not fully functional during this phase of startup the Bypass Inoperable Status Indication (BISI) program did not provide a back up indication that the EFW system was out of alignment.
Condition Evaluation Report (CER) 05-2620 is incorporating this and 2 other human performance CERs which were of high visibility intc a common cause evaluation for problem resolution.
CORRECTIVE ACTIONS
Immediate corrective action was taken to place the "A" MDEFP switch in Normal After Stop. This returned the pump to Operable status.
VCSNS has initiated the following programmatic improvements to install barriers and controls on mode escalation:
- General Operating Procedures (GOPs) are being revised to reference the Surveillance Test Procedure (STP) that needs to be performed prior to applicable mode changes.
- The STP has been revised to restore/ensure EFW pumps and valves are in the required operable position.
- A crew mode change sheet was developed and will be implemented prior to mode changes.
In addition to the above program changes: compensatory actions are being developed to monitor safeguards system status should the BISI system become inoperable.
All corrective actions will be completed prior to the next VCSNS refueling outage (RF-16) currently scheduled to begin in October 2006
PRIOR OCCUR ENCES
No prior occurrences were identified in which an EFW pump was in PTL during Mode 3 entry.