05000498/LER-2004-005

LER-2004-005, Standby Diesel Generator 12 Not Being Declared Inoperable While the Auxiliary Feedwater Pump 12 Breaker Cell Switch was Being Replaced

Docket Number
Event date:	08-18-2004
Report date:	10-25-2004
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
4982004005R00 - NRC Website

This event is reportable pursuant to 10CFR50.73(a)(2)(i)(B) as an operation or condition prohibited by Technical Specifications.

B. PLANT OPERATING CONDITIONS PRIOR TO THE EVENT

South Texas Project Unit 1 was in Mode 1 operating at 100% power.

START OF THE EVENT AND THAT CONTRIBUTED TO THE EVENT

Unit 1 Auxiliary Feedwater (AFW) Pump 12 ("B" Train) was declared inoperable at 0300 on 11/03/2003 for planned pump breaker cell switch replacement. The maintenance was successfully completed and AFW Pump 12 was subsequently declared operable at 2005 on 11/04/2003. The AFW pump cell switch maintenance rendered the Standby Diesel Generator (SDG) 12 output breaker inoperable. Therefore, during the time the AFW pump breaker cell switch work was in progress, SDG 12 should also have been considered inoperable.

The diesel output breaker is inoperable in this condition due to its inability to recognize the AFW pump breaker as not closed. This prevents auto closure capability of the SDG 12 output breaker during an emergency start.

D. NARRATIVE SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES

In August 2004, during a work review of the Cell Switch Replacement Project, a question was identified regarding the declaration of Sequencer and SDG inoperability during any associated cell switch maintenance. Subsequently, an investigation was initiated regarding this issue. The results of this investigation identified one case in November 2003 where an affected diesel generator had not been declared inoperable due to cell switch maintenance.

On Monday, November 3, 2003 at 0300, AFW pump 12 was declared inoperable in order to perform planned maintenance and Technical Specification action statements 3.7.1.2.a and 3.3.3.5.b were entered. At approximately 0815 on November 4, 2003, work start was granted to commence work to replace the cell switches in the AFW breaker cubicle. The SDG output breaker is inoperable in this condition due to its inability to recognize the AFW pump breaker as not closed. This prevents automatic closure capability of the SDG output breaker during an emergency start.

There is no documented evidence that SDG 12 was considered inoperable during this time period (i.e.

while the cell switch replacement in the AFW breaker cubicle was in progress). Additionally, there is no evidence of entry in to the required Technical Specification 3.8.1.1.b or performance of the associated ESF Power Availability surveillance.

Therefore, pursuant to 10CFR50.73(a)(2)(i)(B), this event is reportable due to Technical Specification 3.8.1.1.b not being entered and the corresponding failure to perform the associated conditional ESF Power Availability surveillance.

This condition was identified during a historical review and comparison of LCO entries versus Maintenance Rule unavailability.

II.�COMPONENT OR SYSTEM FAILURES

A. FAILURE MODE, MECHANISM, AND EFFECTS OF EACH FAILED COMPONENT

N/A

B. CAUSE OF EACH COMPONENT OR SYSTEM FAILURE

N/A

COMPONENTS WITH MULTIPLE FUNCTIONS

N/A

D. FAILED COMPONENT INFORMATION

N/A III.�ANALYSIS OF THE EVENT

A. SAFETY SYSTEM RESPONSES THAT OCCURRED

N/A

B. DURATION OF SSAFETY SYSTEM TRAIN INOPERABILITY

Standby Diesel Generator 12 was inoperable from approximately 0815 hours0.00943 days <br />0.226 hours <br />0.00135 weeks <br />3.101075e-4 months <br /> on 11/04/2003 until 2005 hours0.0232 days <br />0.557 hours <br />0.00332 weeks <br />7.629025e-4 months <br /> on 11/04/2003.

C. SAFETY CONSEQUENCES AND IMPLICATIONS

This event did not adversely affect the safety of the public or station personnel. There was no release of radiation as a result of this incident.

IV.�CAUSE OF THE EVENT The root cause of this event is inadequate communication to those Senior Reactor Operator's responsible for the configuration management (Control Room) and work implementation processes of this condition where AFW Pump breaker maintenance affects Diesel Generator operability.

1. Subsequent to this incident, the work control process has been revised. Changes include the assigning of a single Work Week Coordinator the majority of the duties that were previously handled by a Unit Supervisor/Work Start Authority, the Work Week Coordinator, and the Work Week Scheduler. This organizational change greatly enhances communication between the planners, schedulers and the control room.

2. This incident is included in the Lessons Learned portion of Licensed Operator Requalification training discussing the importance of work package review prior to approving ECOs or work start for maintenance packages.

3. The constructive discipline policy was applied to the Work Start Authority who provided work start approval for the maintenance package discussed in this incident.

VI.�PREVIOUS SIMILAR EVENTS 1. CR 01-2281: Failed to complete ESF Power Availability surveillance, within one hour of entry into Technical Specification 3.8.1.1.

2. CR 02-5899: The requirement to perform ESF Power Availability surveillance for was not met.

3. CR 04-2237: The one hour time requirement to verify operability of offsite power sources satisfying the requirements of TS 3.8.1.1.b was not met during an ECO execution that made Standby Diesel Generator 11 inoperable.