05000413/LER-2010-004, For Catawba, Unit 1, Regarding Technical Specification Violation Involving Notice of Enforcement Discretion Due to Failure of Diesel Generator Engine-Mounted Thermocouple
| ML102660030 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 09/16/2010 |
| From: | Morris J Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 10-004-00 | |
| Download: ML102660030 (9) | |
| Event date: | |
|---|---|
| Report date: | |
| 4132010004R00 - NRC Website | |
text
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.I F7 Duke k-- Energy JAMES R. MORRIS Vice President Duke Energy Corporation Catawba Nuclear Station 4800 Concord Road York, SC 29745 803-701-4251 803-701-3221 fax September 16, 2010 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555
Subject:
Duke Energy Carolinas, LLC (Duke)
Catawba Nuclear Station, Unit 1 Docket No. 50-413 Licensee Event Report 413/2010-004 Attached is Licensee Event Report 413/2010-004, Revision 0 entitled, "Technical Specification Violation Involving Notice of Enforcement Discretion Due to Failure of Diesel Generator Engine-Mounted Thermocouple".
There are no regulatory commitments contained in this letter or its attachment.
This event is considered to be of no significance with respect to the health and safety of the public. If there are any questions on this report, please contact L.J. Rudy at (803) 701-3084.
Sincerely, James R. Morris LJR/s Attachment www duke-energy com
Document Control Desk Page 2 September 16, 2010 xc (with attachment):
L.A. Reyes Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 J.H. Thompson (addressee only)
NRC Project Manager U.S. Nuclear Regulatory Commission Mail Stop 8-G9A 11555 Rockville Pike Rockville, MD 20852-2738 G.A. Hutto, III NRC Senior Resident Inspector Catawba Nuclear Station INPO Records Center 700 Galleria Place Atlanta, GA 30339-5957
Document Control Desk Page 3 September 16, 2010 bxc (electronic copy)(with attachment):
INPO L.E. Harmon S.B. Putnam R.D. Hart G.Y. Helton S.F. Hatley (EPIX)
M.K. Green R.T. Simril, Jr.
B.C. Carroll A.M. Peterman K.D. Thomas R.G. Hull T.W. King K.R. Alter H.D. Brewer K.L. Ashe B.J. Horsley M.J. Brown lerevents@inpo.org Lee.Harmon@NRC.gov bxc (hard copy)(with attachment):
C.J. Thomas L.S. Nichols G.F. Winkel L.J. Rudy ELL Master File CN-801.01 LER File RGC Date File NCMPA-1 NCEMC PMPA
Abstract
On July 30, 2010 at 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br />, Technical Specification (TS) 3.8.1, "AC Sources - Operating" and three supported system TS were violated when the 72-hour Completion Time for Diesel Generator (DG) 1A expired.
TS 3.8.1, Condition B had been previously entered following the failure of an engine-mounted exhaust thermocouple. The failed thermocouple was subsequently located in the stationary vane of the right bank turbocharger. On the afternoon of July 29, 2010, the NRC granted enforcement discretion concerning TS 3.8.1, Condition B and its supported system TS. The period of enforcement discretion began on July 30, 2010 at 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> and was to be effective for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. DG 1A was subsequently returned to operable status and all applicable TS Conditions were exited by July 30, 2010 at 0308 hours0.00356 days <br />0.0856 hours <br />5.092593e-4 weeks <br />1.17194e-4 months <br />. This was prior to the time that Unit 1 would have had to be placed in Mode 3 absent the granting of enforcement discretion (0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> on July 30, 2010).
The thermocouple failure was determined to be due to mechanical fatigue resulting from high-cycle, low-amplitude, cyclic stresses.
Planned corrective actions include replacing all exhaust thermocouples in both DGs on Units 1 and 2.
The failure of the thermocouple did not affect the ability of DG 1A to perform its safety related function following an event for which emergency AC power would have been required. Therefore, the health and safety of the public were not adversely affected by this event.
NRC FORM 366 (9-2007)
(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
Only one hour and eight minutes was eventually utilized out of the 24-hour period of enforcement discretion granted by the NRC. The probabilistic risk analysis and other technical information contained in the enforcement discretion request fully supported the 24-hour extension of the applicable TS Completion Times. The details of the enforcement discretion request can be found in the letter from Duke Energy to the NRC dated August 2, 2010 (ADAMS Accession Number ML102160562). The NRC letter granting the enforcement discretion request was issued on August 9, 2010 (ADAMS Accession Number ML102220252).
This event did not affect the health and safety of the public.
ADDITIONAL INFORMATION
Within the previous three years, there have been no LER events involving the failure of a DG thermocouple or involving a request for enforcement discretion. There have been other LER events involving TS violations; however, the specific circumstances surrounding those events and the corrective actions taken in response to those events could not have prevented this event from occurring. This event is therefore considered to be non-recurring.
Energy Industry Identification System (EIIS) codes are identified in the text as [EIIS: XX]. This event is not considered reportable to the Equipment Performance and Information Exchange (EPIX) program.
This event is not considered to constitute a Safety System Functional Failure. This event only affected the operability of DG 1A when the DG was taken out of service for troubleshooting and maintenance following the discovery of the failed thermocouple. DG 1 B remained operable throughout this event. There was no release of radioactive material, radiation overexposure, or personnel injury associated with the event described in this LER.