05000499/LER-2010-002, Regarding Unanalyzed Condition Regarding the Fire Protection System
| ML100750246 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 03/11/2010 |
| From: | Peter L South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-10002529 LER 10-002-00 | |
| Download: ML100750246 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4992010002R00 - NRC Website | |
text
Nuclear Operating Company South Texas Project Electric GeneratinS Station P.. Box 289 Wadsworth Texas 77483 March 11, 2010 NOC-AE-10002529 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 South Texas Project Unit 2 Docket No. STN 50-499 Licensee Event Report 2-2010-002 Unanalyzed Condition Regarding the Fire Protection System Pursuant to 10 CFR 50.73, the STP Nuclear Operating Company (STPNOC) submits the attached Unit 2 Licensee Event Report 2-2010-002 as a result of the inadvertent isolation of the fire water supply header for fire areas in Unit 2 where the Fire Hazards Analysis credits the availability of water suppression for safe shutdown in the event of a fire. This condition is reportable under 10 CFR 50.73(a)(2)(ii)(B) as an unanalyzed condition that significantly degraded plant safety.
This event did not have an adverse effect on the health and safety of the public.
There are no commitments contained in this Licensee Event Report. Corrective actions were processed in accordance with the STP Corrective Action Program.
If there are any questions on this submittal, please contact either Ken Taplett (361) 972-8416 or me at (361) 972-7158.
L. W. Peter Plant General Manager KJT
Attachment:
LER 2-2010-002, Unanalyzed Condition Regarding the Fire Protection System STI: 32623787
NOC-AE-10002529 Page 2 cc:
(paper copy)
(electronic copy)
Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 612 East Lamar Blvd, Suite 400 Arlington, Texas 76011-4125 Mohan C. Thadani Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 8B1A) 11555 Rockville Pike Rockville, MD 20852 Senior Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP Mohan C. Thadani U. S. Nuclear Regulatory Commission Kevin Howell Catherine Callaway Jim von Suskil NRG South Texas LP Ed Alarcon J. J. Nesrsta R. K. Temple Kevin Pollo City Public Service Jon C. Wood Cox Smith Matthews C. Mele City of Austin Richard A. Ratliff Texas Department of State Health Services Alice Rogers Texas Department of State Health Services
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSIO APPROVED BY OMB NO. 3150-0104 EXPIRES: 8/31/2010 (9-2007)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the a
finformation collection.
- 3. PAGE South Texas Unit 2 05000499 1 OF 5
- 4. TITLE Unanalyzed Condition Regarding the Fire Protection System
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCUMENTNUMBER NUMBER NO.
05000 07 07 2008 2010
--002 --
00 03 11 2010 FACILITY NAME DOCUMENT NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
Mode 1
[] 20.2201(b)
LI 20.2203(a)(3)(i)
[]
50.73(a)(2)(i)(C)
[]
50.73(a)(2)(vii)
[I 20.2201(d)
[]
20.2203(a)(3)(ii)
[]
50.73(a)(2)(ii)(A)
[]
50.73(a)(2)(viii)(A)
[] 20.2203(a)(1)
E]
20.2203(a)(4)
U 50.73(a)(2)(ii)(B)
E] 50.73(a)(2)(viii)(B)
[]
20.2203(a)(2)(i)
[]
50.36(c)(1)(i)(A)
Li 50.73(a)(2)(iii)
[L]
50.73(a)(2)(ix)(A)
- 10. POWER LEVEL LI 20.2203(a)(2)(ii)
[I 50.36(c)(1)(ii)(A)
Li 50.73(a)(2)(iv)(A)
L] 50.73(a)(2)(x) 100%
20.2203(a)(2)(iii)
[]
50.36(c)(2)
[]
50.73(a)(2)(v)(A)
[]
73.71(a)(4)
[] 20.2203(a)(2)(iv)
[]
50.46(a)(3)(ii)
[]
50.73(a)(2)(v)(B)
[]
73.71 (a)(5)
L] 20.2203(a)(2)(v)
L] 50.73(a)(2)(i)(A)
L] 50.73(a)(2)(v)(C)
LII OTHER Li 20.2203(a)(2)(vi)
E]
50.73(a)(2)(i)(B)
L] 50.73(a)(2)(v)(D)
VOLUNTARY LER
- 12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (Include Area Code)
Ken Taplett, Licensing Engineer 361-972-8416CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH 0DAY YEAR SBMISSO Li YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
E NO SUDATESION ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On July 7, 2008 at 2211 hours0.0256 days <br />0.614 hours <br />0.00366 weeks <br />8.412855e-4 months <br />, both Unit 1 and Unit 2 control rooms received fire detection system alarms on the fire detection computer due to reduced pressure in an isolated portion of the fire protection main ring header. In response to the alarms, an Equipment Clearance Order was released that had isolated the header. The number one diesel-driven fire pump was started to maintain system pressure. The fire protection main ring header was restored to service on July 8, 2008 at 0057 hours6.597222e-4 days <br />0.0158 hours <br />9.424603e-5 weeks <br />2.16885e-5 months <br />.
The root cause of the inadvertent isolation of a portion of the fire protection main ring header was the general absence of adequate process controls for assessing the aggregate impact of multiple work activities on the fire protection system functionality.
Corrective actions included revising procedures for establishing fire protection system functionality requirements and for establishing plant operations department administrative guidelines to provide clear guidance and direction for removal of fire protection system components and/or sections of the fire water main from service. A fire protection system owner was designated to coordinate all activities that affect system configuration.
The inadvertent isolation of a portion of the fire protection main ring header adversely impacted three fire areas in Unit 2 containing redundant safe shutdown equipment. The Fire Hazards Analysis credits the availability of water suppression in these affected fire areas for safe shutdown in the event of a fire. This event resulted in no personnel injuries, no offsite radiological releases, and no damage to safety-related equipment.
NRC FORM 366 (9-2007)
PRINTED ON RECYCLED PAPER (If more space is required, use additional copies of SUMMARY OF THE EVENT (include dates and approximate times)
On July 6, 2008 at 1325 hours0.0153 days <br />0.368 hours <br />0.00219 weeks <br />5.041625e-4 months <br />, an equipment clearance order (ECO) was approved in Unit 2 that removed part of the fire protection main ring header from service. On July 7, 2008 at 1929 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.339845e-4 months <br />, a different ECO was approved in Unit 1 that removed additional parts of the fire protection main ring header from service.
On July 7, 2008 at 2211 hours0.0256 days <br />0.614 hours <br />0.00366 weeks <br />8.412855e-4 months <br />, both Unit 1 and Unit 2 control rooms started to receive fire detection system alarms on the fire detection computer due to reduced pressure in the isolated portion of the fire protection main ring header. In response to the alarms, Unit 1 approved release of the ECO previously approved for this Unit. The number one diesel-driven fire pump was started to maintain system pressure. The fire protection main ring header was restored to service on July 8, 2008 at 0057 hours6.597222e-4 days <br />0.0158 hours <br />9.424603e-5 weeks <br />2.16885e-5 months <br />.
Subsequent investigation determined that an ECO in Unit 2 supported a different work package than the work package that was supported by the ECO in Unit 1. Although the work week management was aware that both work packages were scheduled for the same work week, work schedule reviews did not identify the aggregate impact on the fire protection main ring header functionality if both jobs were worked simultaneously.
The isolation of a portion of the fire protection main ring header adversely impacted three fire areas in Unit 2 containing redundant safe shutdown equipment. No fire areas in Unit 1 containing redundant safe shutdown equipment were adversely impacted. The Fire (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) multiple work activities on the fire protection system functionality.
V.
CORRECTIVE ACTIONS
Procedures for establishing fire protection system functionality requirements and for establishing plant operations department administrative guidelines were revised to provide clear guidance and direction for removal of fire protection system components and/or sections of the fire water main from service.
A fire protection system owner was designated to coordinate all activities that affect system configuration.
VI.
PREVIOUS SIMILAR EVENTS
There have been no previous Licensee Event Reports within the last three years involving an unanalyzed condition that significantly degraded plant safety.
In 2007, the fire suppression system to the Unit 1 Emergency Safety Features (ESF) Diesel Generators was inadvertently isolated. This event was determined to not be an unanalyzed condition that significantly degraded plant safety. The Fire Hazards Analysis credits compartmentalization for ensuring that one safe shutdown train remains available in the event of a fire in any of the fire areas that contain the ESF Diesel Generators. Suppression is not credited in the achievement of safe shutdown for these areas.
VII.
ADDITIONAL INFORMATION
This event was initially determined to be not reportable. A re-evaluation of the event determined that the condition described in this event report represented an unanalyzed condition that significantly degraded plant safety and therefore is reportable pursuant to 10 CFR 50.73(a)(2)(ii)(B). A notification of the event pursuant to 10 CFR 50.72(b)(3)(ii)(B) was made to NRC on January 14, 2010 at 1659 hours0.0192 days <br />0.461 hours <br />0.00274 weeks <br />6.312495e-4 months <br /> (Event Notification 45631).PRINTED ON RECYCLED PAPER