05000282/LER-2001-001
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| Initial Reporting | |
| 2822001001R00 - NRC Website | |
EVENT DESCRIPTION
On February 21, 2001, during preparation to bring the Unit 1 Reactor Coolant Systems (RCS) above 200 degrees F, valves2 SI-8-1 and SI-8-2 were verified locked in the proper position to support the 11 Boric Acid Storage Tank3 (BAST) as the suction source to the safety injection (SI) pumps4. Due to problems with the level indication on the 11 BAST, the 121 BAST was lined up for safety injection on Unit 1. Sl-8-1 and Sl-8-2 were aligned and tagged with Hold Cards per Operating Procedure C12.6, but were not locked.
On February 22, 2001, the Unit 1 RCS temperature exceeded 200 degrees F. At this point, Technical Specification 3.2.B.7 requires that these valves be locked in the proper position.
On March 14, 2001, with the reactor at 100% power, the duty Reactor Operator was giving a license trainee a check-off on the procedure C12.6. At this time it was noted that the procedure did not address re-locking the manual outlet isolation valve in position as required by Technical Specification 3.2.B.7.
An operator was dispatched to determine the status of manual valve SI-8-2 (121 BAST SUPPLY TO SI PUMPS). The operator reported to the control room that the valve was open (in the correct position), but not locked as required by Technical Specifications. A chain and lock was delivered to the operator and the valve was locked into position.
On March 21, 2001, upon further investigation site personnel determined that valve SI-8-1 (11 BAST SUPPLY TO SI PUMPS), which was in the correct position, but not locked, should also be locked. SI-8- 1 was subsequently locked.
CAUSE OF THE EVENT
Prairie Island personnel performed an investigation to determine the root cause for failing to lock valves SI-8-2 and SI-8-1 as required by Technical Specifications. The evaluation concluded that the primary cause of the event was the failure of the system lineup procedure to specify locking of the valves.
Secondary causes of the event include:
1. Reviews during procedure change process did not catch the omission of Technical Specification requirements in the procedure.
2. Periodic reviews of the procedure did not catch the omission of Technical Specification requirements in the procedure.
3. Operations personnel were unable to devise a method using the Safeguards Hold Tag process to control a valve that has differing required positions based on which tank is in service. Valve Sl-8-2 has two different safeguards positions, depending on which BAST is in service.
1 (EIIS System Identifier: AB) 2 (EIIS Component Identifier: V) 3 (EIIS Component Identifier: TK) 4 (EIIS Component Identifier: P)
ANALYSIS OF THE EVENT
Valve SI-8-2 was found in the correct position to support safety injection, but not locked in position as required by Prairie Island Technical Specifications. There were Hold Cards on the valves, which is another form of administrative control. Since the valve was in the proper position and had a level of administrative control on its position, the safety injection function was not affected and, thus, there was no impact on the health and safety of the public.
This event involved manual valves found in the correct position, but not locked in place as required by Prairie Island Technical Specification 3.2.B.7. Therefore, this event is reportable per 10CFR 50.73(a)(2)(i)(B).
On April 16, 2001, the NRC issued License Amendment No. 156 to Facility Operating License No. DPR- 42 (Unit 1) and Amendment No. 147 to Facility Operating License No. DPR-60 (Unit 2), which removed the affected section from the Prairie Island Technical Specifications.
Loss of Safety Function and other Performance Indicator Impact Safety function was not lost because the manual valves were found in the correct position (and administratively controlled) to support Safety Injection. No equipment was declared either inoperable or unavailable. None of the other performance indicators will be affected by this event.
Significance Determination The affected valves were found unlocked, however, they were not mispositioned. This event is limited to the failure to apply an administrative control (locking valves in position). As such, this is viewed as an event of low risk significance.
CORRECTIVE ACTION
1. The valves that were found unlocked, SI-8-2 and SI-8-1, were locked.
2. A level 1 Condition Report (GEN 20012503) to assess this event was entered into the Prairie Island Corrective Action Process on March 14, 2001. The Condition Report was closed out on April 27, 2001. Corrective Actions generated as a result of this Condition Report include:
- Correct the procedure and associated checklists to provide two options for locking and tagging SI-8-1 and SI-8-2, depending on which BAST is in service.
- Provide operations training to stress the importance of Safeguards Hold Cards and locks and what they are protecting.
- Have all operations crews review the condition report associated with this event.
The procedure and checklist actions are complete and the other actions are in progress and will be tracked to completion in the Prairie Island Corrective Action Process.
3. License Amendment No. 156 to Facility Operating License No. DPR-42 and Amendment No. 147 to Facility Operating License No. DPR-60, remove the BAST as a credited suction source to the Safety Injection system. Implementation of the Amendment will preclude recurrence with respect to the valves SI-8-2 and SI-8-1 because the Technical Specification section that was violated as a result of this event is deleted by the amendment.
FAILED COMPONENT IDENTIFICATION
None.
PREVIOUS SIMILAR EVENTS
No other events that involve failing to provide Technical Specification-required controls on equipment have been reported in the past three years.