05000311/LER-2001-004
| Salem Generating Station Unit 2 | |
| Event date: | 07-26-2001 |
|---|---|
| Report date: | 09-21-2001 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3112001004R00 - NRC Website | |
PLANT AND SYSTEM IDENTIFICATION
Westinghouse - Pressurized Water Reactor High Pressure Safety Injection System / Injection valve {BQ/INV}* * Energy Industry Identification System (EIIS) codes and component function identifier codes appear in the text as {SS/CCC}.
IDENTIFICATION OF OCCURRENCE
Event Date: July 26, 2001 Discovery Date: August 10, 2001
CONDITIONS PRIOR TO OCCURRENCE
MODE 1 (POWER OPERATION) No structures, systems, or components were inoperable at the time of the occurrence that contributed to the event.
DESCRIPTION OF OCCURRENCE
On August 10, 2001, a failure to comply with Salem Unit 2 Technical Specification (T/S) 3.6.3, Containment Isolation Valves was identified. This condition was identified during an evaluation of circumstances surrounding the maintenance performed on Boron Injection Tank Outlet Valve S2SJ-2SJ12 (2SJ12) {BQ/INV) on July 26, 2001.
At approximately 0500 on July 26, 2001, licensed plant personnel de-energized the 2SJ12 and placed the valve on its open backseat to allow packing replacement. This rendered the motor operated valve inoperable. T/S action statement (TSAS) 3.5.2.a, Emergency Core Cooling System Subsystems, was entered with an allowed outage time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. 2SJ12 is also a listed containment isolation valve as described in section 6.2 of the Salem UFSAR and is subject to the requirements of T/S 3.6.3. Valve 2SJ12 was not considered a containment isolation valve by licensed operators and therefore the action requirements of T/S 3.6.3 were not applied. This resulted in a condition prohibited by the plant's T/S.
The packing replacement on 2SJ12 was completed and the normal configuration of the Safety Injection System was restored. At 2111 on July 26, 2001, TSAS 3.5.2.a was exited.
CAUSE OF OCCURRENCE
The apparent cause of the failure to comply with T/S was due to inconsistent information in the Salem UFSAR and Salem In Service Testing (IST) manual valve data sheets in that valve 2SJ12 was not clearly identified as a containment isolation valve. An incomplete understanding of the information presented in section 6.2 of the Salem UFSAR and the Salem IST manual valve data sheets existed. Some operators did not recognize that 2SJ12 was listed as a containment isolation valve in the Salem UFSAR. Some operators did, but were convinced that T/S 3.6.3 did not apply due to conflicting statements in the Salem UFSAR and the Salem IST manual regarding the valve's safety function.
PREVIOUS OCCURRENCES
A review of events over the past two years identified no reportable events due to a failure to comply with Technical Specifications due to inconsistent licensing basis information at Hope Creek or Salem Generating Stations.
SAFETY CONSEQUENCES AND IMPLICATIONS
There were no actual safety consequences associated with this event. The safety significance of this event was minimal in that the affected penetration was isolated by closure of the Boron Injection Tank Inlet Valves S2SJ-2SJ4/5 (2SJ4/5). Also, its safety function is to open upon a safety injection signal.
Potential safety consequences of this event were mitigated because:
a. The primary safety function of 2SJ12 is to automatically open allowing safety injection flow during a loss of reactor coolant system inventory. This function was retained with the valve de-energized and placed on its open backseat.
b. Valve 2SJ12 is a listed containment isolation valve. This is supported by its inclusion in Table 6.2-10 of the Salem UFSAR, by the text of section 6.2 of the Salem UFSAR and the functions described in the IST program valve data sheet for 2SJ12. There are statements within all three of these references that conflict with the idea of 2SJ12 as a containment isolation valve. This function was not retained with the valve placed on its backseat. However, the position of other components mitigated potential safety consequences of a containment overpressure event if it had occurred during the 2SJ12 repair. The Boron Injection Tank to Cold Leg Check valve S2SJ-2SJ150 (2SJ150) fBQ/INVI served as a containment isolation valve inside containment. This check valve is tested during refueling outages. Outside containment, the 2SJ4/5 valves were closed prior to opening 2SJ12.
A review of this event determined that a Safety System Functional Failure (SSFF) as defined in Nuclear Energy Institute (NEI) 99-02, Regulatory Assessment Performance Indicator Guideline, did not occur.
CORRECTIVE ACTIONS
1. A review of the licensing and design basis of all valves included in Salem USFAR Table 6.2-10 (including 2SJ12) will be conducted. Clarifications or changes to the information presented in the table so the containment isolation function of all valves is clearly identified will be made.
2. A common cause analysis of Technical Specification and Licensing related issues (notifications) at Salem since January 1, 2000 will be conducted.
3. A review of this event will be conducted with licensed operators. The review will include a detailed discussion of the T/S 3.6.3, section 6.2.4.2 of the Salem UFSAR, and Table 6.2-10 of the Salem UFSAR.
COMMITMENTS
The corrective actions cited in this LER are voluntary enhancements and do not constitute commitments.