05000454/LER-2012-002, Regarding One Train of Containment Cooling System Inoperable Longer than Allowed by Technical Specifications Due to Inadequate Work Instructions
| ML12151A005 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 05/29/2012 |
| From: | Tulon T Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2012-0062 LER 12-002-00 | |
| Download: ML12151A005 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| 4542012002R00 - NRC Website | |
text
Exelon GeneratlOn Company, llC Byron Station 4450 North German Church Road Byron, Il 61010-9794 May 29,2012 Byron Ltr 2012 - 0062 File # 1.10.0101 www,exeloncorp,com U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Unit 1 Facility Operating License No. NPF-37 NRC Docket No. STN 50-454 Exelon.
Nuclear 10 CFR 50.73 Subject: Licensee Event Report 2012-002-00, "One Train of Containment Cooling System Inoperable Longer Than Allowed by Technical Specifications Due to Inadequate Work Instructions" The enclosed Licensee Event Report (LER) is being submitted in accordance with 10 CFR 50.73, "Licensee event report system," paragraph (a)(2)(i)(B), as a condition prohibited by Technical Specifications and paragraph (a)(2)(v)(B), as an event or condition that could have prevented fulfillment of a safety system. The LER involves the inadvertent inoperability of a Unit 1 Containment Cooling train due to failing to re-install an internal access panel in a cooling plenum.
There are no regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact Mr. David Gudger, Regulatory Assurance Manager, at (815) 406-2800.
ReSpectfu~
T~~. TUlon S~~~ PreSident Byron Station
Enclosure:
LER Number 454-2012-002-00
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150~104 EXPIRES: 10/31/2013 (10-2010)
Estimated burdon per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into the licenSing process and fed back to ind~
Send comments regarding burden estimate to the FO~Section -5 F53). U.S. Nuclear Regulatory Commission. Washington.
2O~1.
or by internat e-mail to LICENSEE EVENT REPORT (LER) infocoUects.resource@nrc.~. and to the Desk Officei. Office of Information and RoguIatoryAffairs. NE B*10202. (31~104). Office of Management and Budget. Washington. DC 20503. If a means used to impose an information (See reverse for required number of collection does not display a currently valid OMS control number. the NRC may digits/characters for each block) not conduct or sponsor. and a person is not required to respond to. the information collection.
- 1. FACIUTY NAME
- 2. DOCKET NUMBER
- 13. PAGE Byron Station, Unit 1 05000454 1 OF 3
- 14. nTLE One Train of Containment Cooling System Inoperable Longer Than Allowed by Technical Specifications Due to Inadequate Work Instructions
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FAClunES INVOLVED YEAR I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO.
MONTH DAY YEAR N/A FACILITY NAME DOCKET NUMBER 04 21 11 2012. 002. 00 05 29 2012
- 9. OPERAnNG MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR I: (Checkallthatapply) 1 D 20.2201 (b)
D 2O.2203(a)(3)(i)
D SO.73(a)(2)(i)(C)
D SO.73(a)(2)(vii)
D 20.2201 (d)
D 2O.2203(a)(3)(ii)
D SO.73(a)(2)(ii)(A)
D SO.73(a)(2)(viii)(A)
D 2O.2203(a)(1)
D 2O.2203(a)(4)
D SO.73(a)(2)(ii)(B)
D SO.73(a)(2)(viii)(B)
D 2O.2203(a)(2)(i)
D SO.36(c)(1 )(i)(A)
D SO.73(a)(2)(iii)
D SO.73(a)(2)(ix)(A)
- 10. POWER LEVEL D 2O.2203(a)(2)(ii)
D SO.36(c)(1 )(ii)(A)
D SO.73(a)(2)(iv)(A)
D SO.73(a)(2)(x)
D 2O.2203(a)(2)(iii)
D SO.36(c)(2)
D SO.73(a)(2)(v)(A)
D 73.71(8)(4) 100 D 2O.2203(a)(2)(iv)
D SO.46(a)(3)(ii) rgJ SO.73(a)(2)(v)(B)
D 73.71 (a)(5)
D 2O.2203(a)(2)(v)
D SO.73(a)(2)(i)(A)
D SO.73(a)(2)(v)(C)
D OTHER D 2O.2203(a)(2)(vi) rgJ SO.73(a)(2)(i)(B)
D SO.73(a)(2)(v)(O)
Specify in Abstract below or in C. CauseJs of the Event
- 6. LER NUMBER I
seQUENTIAL j REV NUMBER NO.
002 00
- 3. PAGE 3
OF 3
The cause was determined to be an inadequate level of details in the work package for the March 15, 2011, removal of the 1 A RCFC panels. The work package generically stated to remove panels and did not specifically identify each panel to be removed and reinstalled. A separate work crew re-installing the panels on April 19, 2011, did not recognize the interior panel was removed and, therefore only re-installed the plenum access panel.
Contributing causes include insufficient drawing details concerning the panels in terms of number of panels and locations and the panels not having unique equipment identifier.
D. Safety Significance
There were no actual safety consequences as a result of the diminished cooling capacity of the 1A VP train. The 1 B VP train was operable during this period except for four occasions; on August 31,2011, for approximately 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />, December 29,2011 for approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, March 29, 2012 for 26 minutes and March 29, 2012 for 33 minutes. During these periods both Unit 1 CS trains were operable. An engineering analysiS is being pursued to determine the potential significance of the diminished cooling capability of the 1 A RCFC. The results of the analysis will be provided in a supplement to this report.
E. Corrective Actions
The remaining RCFC plenums in Unit 1 were inspected and all other internal panels were found properly installed.
Unit 2 RCFC plenums will be inspected in the next refueling outage.
The RCFC panels will be given unique equipment identifiers and each panel will be labeled accordingly.
The drawings will be revised to reflect equipment identification for the RCFC panels.
The model work package for the RCFC panel removal will be revised to include instructions for each panel to be removed and re-installed; to include their unique identification number.
F. Previous Occurrences
No previous events were identified at Byron Station in previous three years.