05000361/LER-2008-008

LER-2008-008, Missed Technical Specification Surveillance Requirement on Spare Station Battery BOOX

Docket Number
Event date:	07-15-2008
Report date:	4-03-2009
3612008008R01 - NRC Website

Event Date: July 15, 2008 Reactor Vendor: Combustion Engineering Mode: Mode 1 — Power Operation Power: 99 percent

Description of Event

San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 has eight Class 1 E 125 VDC Station Batteries; 4 for each unit. SONGS utilizes a fully qualified spare 125 VDC battery (BOOX) as a substitute battery during replacement and testing of existing Class 1 E 125 VDC Station Batteries [EJ]. BOOX can be utilized as a temporary spare for the existing station batteries in both Units 2 and 3, and, in order to be declared operable, is subject to the same Technical Specification (TS) Surveillance Requirements (SR) as the existing installed station batteries.

TS 3.8.4, "DC Sources — Operating," delineates the Limiting Condition for Operation (LCO), Actions, and SRs associated with the four trains of DC electrical power subsystems. TS 3.8.4.A requires that with one battery inoperable, the associated DC electrical power subsystem must be restored to operable status within two hours. If TS 3.8.4.A is not met, TS 3.8.4.B requires that the plant be placed in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

TS 3.8.6, "Battery Cell Parameters," delineates the applicable LCO, Actions, and SR's associated with the 125 VDC Station Batteries. To satisfy the LCO, in-service batteries must be current on SRs 3.8.6.1, 3.8.6.2 and 3.8.6.3. SR 3.8.6.2 is a quarterly surveillance that verifies battery cell parameters meet applicable limits specified in TS Table 3.8.6-1, "Battery Surveillance Requirements.

On July 15, 2008 (event date), at about 1403 PDT, to allow work on station battery 2B008, station battery BOOX was declared operable and placed in-service. On July 17, 2008, at approximately 1424 PDT, 2B008 was returned to service and BOOX was removed from service.

On October 23, 2008 (discovery date), SCE identified that when BOOX was placed in-service on July 15, 2008, it did not have a current quarterly surveillance for SR 3.8.6.2. Consequently, LCOs 3.8.6 and 3.8.4 were unknowingly violated when BOOX was placed in-service on July 15, 2008. The required quarterly surveillance on BOOX was successfully performed on July 26, 2008.

Cause of the event

This event was caused by a combination of incorrect procedure use and failure to properly implement a transition plan for scheduling TS surveillances. A quarterly surveillance was improperly pen-and-ink modified to a weekly surveillance. Using this modified surveillance procedure, workers performed the weekly surveillance but the results were recorded as a completed quarterly surveillance. On July 1, 2008, SONGS transitioned from the MOSAIC System (i.e., SONGS tool for tracking work and Corrective Action Program issues) to the new ERP System which significantly changed the process for scheduling TS surveillance testing.

Prior to the transition to ERP, a transition plan was developed to ensure surveillance testing was completed in accordance with the prescribed schedule and TS requirements. This transition plan was not properly implemented. The combination of the inappropriate pen-and-ink change and the failure to properly implement the transition plan resulted in the missed TS SR for BOOX.

Corrective Actions

Completed Corrective Actions

The required BOOX quarterly surveillance test satisfying SR 3.8.6.2 was successfully performed on July 26, 2008.

An extent of condition evaluation was performed which identified other examples where SRs were not completed as scheduled. The other missed SRs were successfully completed after the 25% extension (i.e., 1.25 times the required surveillance interval) allowed by TS SR 3.0.2, but did not result in additional reportable TS violations.

Individuals involved in making and approving the pen-and-ink change to the surveillance Maintenance Order were coached on complying with the applicable procedure requirements.

Planned Corrective Actions

SCE is incorporating lessons learned from this event into the Maintenance training program.

Safety Significance

SR 3.8.6.2 was successfully completed on BOOX on July 26, 2008. Consequently, SCE concludes that there was no safety significance to this event.