05000316/LER-2006-004

LER-2006-004, Failure to comply with Technical Specification 3.8.2, AC Sources - Shutdown, LCO 3.8.2.b

Docket Number
Event date:	04-21-2006
Report date:	06-29-2006
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat
Initial Reporting
3162006004R00 - NRC Website

Description of Event

On May 1, 2006, while in MODE 5 following a planned refueling outage, it was determined that Donald C. Cook Nuclear Plant (CNP) Unit 2 failed to meet the requirements of Technical Specification (TS) 3.8.2, AC Sources - Shutdown, Limiting Condition for Operation 3.8.2.b, for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and 32 minutes between the dates of April 21, 2006, and April 22, 2006. Specifically, between 1204 hours0.0139 days <br />0.334 hours <br />0.00199 weeks <br />4.58122e-4 months <br /> on April 21, 2006, and 0020 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> on did not have an operable emergency diesel generator (EDG) [EK]. During these time periods, the Unit 2 AB EDG was out of service for planned maintenance/surveillance testing activities. Subsequently, plant personnel determined that the Unit 2 CD EDG was also inoperable due to an unidentified latent failure that resulted in mechanical binding of the EDG fuel injector pumps.

This condition is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as an operational condition prohibited by TS 3.8.2, AC Sources — Shutdown and 10 CFR 50.73(a)(2)(v)(B) as an event that could have prevented the removal of residual heat. This report meets the reporting requirements of 10 CFR 21 for nonconforming materials installed in safety-related applications. Because the reportable condition discussed in this licensee event report was identified after the system was returned to operable status, notification of the event in accordance with 10 CFR 50.72, "Immediate notification requirements for operating nuclear power reactors," was not required.

Analysis of Event

A risk analysis/assessment determined that this event had no associated nuclear safety significance. This event did not challenge any of the other key safety functions beyond Electrical Power Sources, as defined in NUMARC 93-01, Section 11, Rev. 2-22-2000.

Cause of Event

The mechanical binding of the Unit 2 CD fuel injector pumps was caused by inadequate barriers that permitted new fuel injection pumps, as supplied by the vendor, to contain foreign material of sufficient size and hardness to damage the pumps.

Corrective Actions

Immediate corrective actions included replacement of the suspect/defective fuel injector pumps and satisfactory retesting of the Unit 2 CD EDG in accordance with plant procedures.

Indiana Michigan Power Company will impose cleanliness requirements on vendors who supply fuel injector pumps for application on the EDGs.

Previous Similar Events

None.