05000339/LER-2007-001, Regarding Damper Leak-by During Preacs Testing Results in Unanticipated Power Reduction
| ML071270275 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/27/2007 |
| From: | Stoddard D Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Plant Licensing Branch III-2 |
| References | |
| 07-0195 LER 07-001-00 | |
| Download: ML071270275 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(ii)(B), Unanalyzed Condition 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 |
| 3392007001R00 - NRC Website | |
text
1 OCFR50.73 Virginia Electric and Power Company North Anna Power Station P. O. Box 402 Mineral, Virginia 23117 April 27, 2007 U. S. Nuclear Regulatory Commission Serial No.:
07-0195 Attention: Document Control Desk NAPS:
JHL Washington, D. C. 20555-0001 Docket No.: 50-339 License No.: NPF-7
Dear Sirs:
Pursuant to 10CFR50.73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to North Anna Power Station Unit 2.
Report No. 50-339/2007-001-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be forwarded to the Management Safety Review Committee for its review.
Sincerely, D. G. Stoddard, Site Vice President North Anna Power Station Enclosure Commitments contained in this letter: None cc:
United States Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 Mr. J. T. Reece NRC Senior Resident Inspector North Anna Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSIO APPROVED BY OMB NO. 3150-0104 EXPIRES: 6/30/2007 (6-2004)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE NORTH ANNA POWER STATION, UNIT 2 05000 339 1 OF 5
- 4. TITLE Damper Leak-by During PREACS Testing Results in Unanticipated Power Reduction
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCUMENT NUMBER NUMBER NO.
05000 02 27 2007 2007
-- 001 --
00 04 27 2007 FACILITY NAME DOCUMENT NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
E] 20.2201(b)
El 20.2203(a)(3)(i)
[-
50.73(a)(2)(i)(C)
[]
50.73(a)(2)(vii)
[] 20.2201 (d)
[]
20.2203(a)(3)(ii)
[]
50.73(a)(2)(ii)(A)
[]
50.73(a)(2)(viii)(A) 1E 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
E7 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
E]
50.36(c)(1)(i)(A) 0 50.73(a)(2)(iii)
F] 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL EZ 20.2203(a)(2)(ii)
[
50.36(c)(1)(ii)(A)
E]
50.73(a)(2)(iv)(A)
ED 50.73(a)(2)(x)
F1 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
[]
73.71 (a)(4)
E] 20.2203(a)(2)(iv)
E]
50.46(a)(3)(ii)
E]
50.73(a)(2)(v)(B)
El 73.71(a)(5)
El 20.2203(a)(2)(v)
E] 50.73(a)(2)(i)(A)
EJ 50.73(a)(2)(v)(C)
[
OTHER 100%
El 20.2203(a)(2)(vi) j]
50.73(a)(2)(i)(B)
[]
50.73(a)(2)(v)(D)
Specify in Abstract below or in (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)
An evaluation will be completed to address potential solutions for damper design deficiencies. Changes will be implemented as appropriate.
Maintenance training programs will be reviewed and revised as required to strengthen maintenance work practices on dampers, damper linkages, and damper actuators.
0-PT-77.14A and B will be revised to include individual testing of PREACS bypass dampers.
These actions will be tracked in the Corrective Action Program to completion.
7.0
SIMILAR EVENTS
Licensee Event Report No. 50-338/1999-006-00 dated September 28, 1999, documents finding a damper associated with the Auxiliary Building General Area Exhaust Ventilation System degraded due to missing damper seals.
Plant Issue N-2006-0504, dated February 6, 2006, documents excessive leakage as measured by 0-PT-77.14B by 2-HV-AOD-228-1 and 2.
8.0 ADDITIONAL INFORMATION
At the time of this event North Anna Unit 1 was operating at 100 percent power and was not affected by this event.
The extent of condition was reviewed and it was determined that it is limited to ventilation system dampers that are required to provide essentially leak-tight sealing, which includes the following: HV-AOD-228-1, -2 (Unit 1 Safeguards Exhaust Bypass Dampers) HV-AOD-103-1, -2 (Auxiliary Building Central Exhaust Bypass Dampers) HV-AOD-1 02-3, -4 (Auxiliary Building General Exhaust Filter Dampers) HV-AOD-1 04-3, -4 (Containment Purge Exhaust Filter Dampers) HV-AOD-107-3, -4 (Fuel Building Exhaust Filter Dampers) HV-AOD-1 13-3, -4 (Waste Solids/Decontamination Building Exhaust Filter Dampers) HV-AOD-160-1, -2 (Control Room Normal Supply Isolation Dampers) HV-AOD-161-1, -2 (Control Room Normal Exhaust Isolation Dampers)
Previous ventilation system testing for North Anna Units 1 and 2 has demonstrated acceptable damper performance.