05000272/LER-2004-003
| Salem | |
| Event date: | 06-02-2004 |
|---|---|
| Report date: | 09-03-2004 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown |
| 2722004003R01 - NRC Website | |
PLANT AND SYSTEM IDENTIFICATION
Westinghouse — Pressurized Water Reactor (PVVR/4) Service Water (SW) {BI} * * Energy Industry Identification System {EIIS} codes and component function identifier codes appear as (SS/CCC)
IDENTIFICATION OF OCCURRENCE
Event Date: June 2, 2004 Discovery Date: June 2, 2004
CONDITIONS PRIOR TO OCCURRENCE
Salem Unit 1 was in Mode 1 at approximately 18% Rated Thermal Power There was no equipment out of service at the time of the event that contributed to the event.
DESCRIPTION OF OCCURRENCE
On June 2, 2004, non-licensed operations personnel identified an abnormal condition in the control of the from its sixteenth refueling outage, the operator noticed that the temperature in the number 11 main turbine lube oil {TD} (MTLO) heat exchanger was approximately 110 degrees F. Further investigation revealed that the service water to the turbine building {NM} regulating valve (1ST1) was full open with only 72 psig in the service water turbine header downstream of 1ST1. These conditions, low pressure and high temperatures, were not normal for the plant conditions at the time.
A detailed troubleshooting plan was developed which included the instrumentation of the service water bays and turbine building header. The data showed the service water pressure to be approximately 130 psig at the Unit 1 service water bays with 83-84 psig upstream of 1ST1. In contrast, the Unit 2 service water pressure at the bays was 112 psig with 109 psig upstream of 2ST1. Additionally, the troubleshooting showed that when the disc was stroked in the clockwise direction, open to close indication on the motor operator, flow increased through the line. Further analyses of this data indicated that the valve 1SW26 was improperly installed and the motor operator improperly set up.
DESCRIPTION OF OCCURRENCE (cont'd.) At Salem Station the service water to the turbine building header isolation valve (1SW26) is required to be operable to maintain containment integrity. During design basis accidents, the 1SW26 valve is required to close fully to isolate the non-safety related loads in the turbine building. Isolation of these loads ensures enough flow and pressure to the containment fan coil units to maintain saturation conditions in the discharge piping. Therefore, the Containment Integrity Technical Specification applies whenever this valve becomes inoperable. The Containment Integrity Technical Specification states in part: "...Without primary CONTAINMENT INTEGRITY, restore CONTAINMENT INTEGRITY within one hour or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />? The Mode applicability is 1 through 4.
At approximately 1230 pm, on June 2, 2004, licensed operators declared the 1SW26 valve inoperable and a plant shutdown was initiated to comply with the requirements of Technical Specification 3.6.1.1, as stated above.
Mode 3 was entered on June 2, 2004 at approximately 1624.
CAUSE OF OCCURRENCE
The Jamesbury butterfly valve-disc rotated after the valve was installed but prior to the motor operated valve (MOV) actuator installation. The root cause of the event is attributed to failure to follow the process of match marking to assure that the actuator was properly installed with respect to the valve position. Break down of the process included the failure to provide detailed shaft to body match marks that could be readily identified by the technicians, and the technicians did not check/verify or have a questioning attitude associated with match marks to assure that the valve — disc position was correct prior to installation of the actuator.
Contributing causal factors identified were: (1) the failure to incorporate a caution note from the technical vendor manual into the procedures to warn of the potential for the disc to open if the actuator was not installed and pressure upstream of the valve increased, and (2) PSEG maintenance and engineering personnel missed an opportunity to remove and inspect the valve because of low torque value during VOTES testing.
PREVIOUS OCCURRENCES
A review of LERs at Salem and Hope Creek Generating Stations for the years 2001 through 2004 did not identify any previous similar events related to improper installation of a valve disc or actuator or failure to follow the process of match marking.
- If
SAFETY CONSEQUENCES AND IMPLICATIONS
There were no safety consequences associated with this event.
Although the 1SW26 service water to the turbine building isolation valve was not able to close fully due to improper installation during the refueling outage, the redundant isolation valves from the two nuclear safety related headers were operable and capable to isolate the non-safety related turbine building.
Therefore, isolation of the non-safety related loads in the turbine building to provide enough flow/pressure to the containment fan coil units to maintain conditions below saturation in the discharge piping would have been met.
This event does not constitute a Safety System Functional Failure (SSFF) as defined in Nuclear Energy Institute (NEI) 99-02, Regulatory Assessment Performance Indicator Guideline.
CORRECTIVE ACTIONS
1. The valve and valve actuator were properly installed and tested satisfactorily.
2. The procedure used for valve and actuator installation will be revised. In addition, the currently scheduled valve work for the upcoming refueling outages will be reviewed to identify potential similar situations and to include the lessons learned in the work package.
3. The lessons learned from this event will be presented to the Training Review Group for inclusion in continuing training.
4. An internal OE will be generated and forwarded to the planning department for incorporation into the library copies of the work orders dealing with similar valves.
5. The MOV procedure will be reviewed and revised to incorporate the lessons learned from this event, as appropriate.
COMMITMENTS
The corrective actions cited in this LER are voluntary enhancements and do not constitute commitments.