05000338/LER-2013-002, Regarding Automatic Reactor Trip Following Actuation of the 1C Station Service Transformer Lockout Relay
| ML14002A242 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 12/06/2013 |
| From: | Gerald Bichof Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 13-581 LER 13-002-00 | |
| Download: ML14002A242 (5) | |
| 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 |
| LER closed by | |
| IR 05000338/2013502 (10 February 2014) | |
| 3382013002R00 - NRC Website | |
text
1 OCFR50.73 Virginia Electric and Power Company North Anna Power Station 1022 Haley Drive Mineral, Virginia 23117 December 6, 2013 Attention: Document Control Desk Serial No.:
13-581 U. S. Nuclear Regulatory Commission NAPS:
JHL Washington, DC 20555-0001 Docket No.: 50-338 License No.: NPF-4
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 1.
Report No. 50-338/2013-002-00 This report has been reviewed by the Facility Safety Review Committee and will be forwarded to the Management Safety Review Committee for its review.
Sincerely, A,~
-~
Gerald T. Bischi)
Site Vice President North Anna Power Station Enclosure Commitments contained in this letter: None cc:
United States Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, Georgia 30303-1257 NRC Senior Resident Inspector North Anna Power Station
I NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)
, 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 1 05000 338 1 OF 4
- 4. TITLE Automatic Reactor Trip Following Actuation of the 1C Station Service Transformer Lockout Relay
- 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 10 11 2013 2013
-- 002--
00 12 06 2013 FACILITY NAME DOCUMENTNUMBER 00j 105000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
Dj 20.2201(b)
E]
20.2203(a)(3)(i)
[
50.73(a)(2)(i)(C)
E]
50.73(a)(2)(vii)
E 20.2201(d)
[
20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A)
[
50.73(a)(2)(viii)(A) 1 20.2203(a)(1)
LI 20.2203(a)(4)
H 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i)
[
50.36(c)(1)(i)(A)
[]
50.73(a)(2)(iii)
H 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL
[]
20.2203(a)(2)(ii)
[
50.36(c)(1)(ii)(A)
[]
50.73(a)(2)(iv)(A)
[: 50.73(a)(2)(x)
LI 20.2203(a)(2)(iii)
[I 50.36(c)(2)
LI 50.73(a)(2)(v)(A)
LI 73.71(a)(4)
LI 20.2203(a)(2)(iv)
[]
50.46(a)(3)(ii)
[
50.73(a)(2)(v)(B)
[]
73.71(a)(5)
LI 20.2203(a)(2)(v)
LI 50.73(a)(2)(i)(A)
LI 50.73(a)(2)(v)(C)
[]
OTHER 48 E] 20.2203(a)(2)(vi)
[
50.73(a)(2)(i)(B)
E] 50.73(a)(2)(v)(D)
Specify in Abstract below or in
3.0 CAUSE
The direct cause was the presence of six shorting screws that were not removed from 1-EP-BKR-1 5C2 cubicle following design change replacement of the under voltage relay.
The root cause of the event was less than adequate written instructions for documenting the installation and removal of shorting screws, which resulted in a loss of configuration control.
The contributing cause of the event was less than adequate training, for maintenance type activities, is provided to Control Operations personnel when compared to station maintenance training programs.
4.0 IMMEDIATE CORRECTIVE ACTION(S)
The Control Room crew responded to the reactor trip in accordance with emergency procedure 1-E-0, Reactor Trip or Safety Injection. The post trip response progressed as expected and the Control Room crew transitioned to 1-ES-0.1, Reactor Trip Response. All safety systems responded as designed.
5.0 ADDITIONAL CORRECTIVE ACTIONS
Visual inspections were performed of all current transformer (CT) blocks for the Generator, Main Transformers and Station Service Transformers. No additional shorting screws were inappropriately installed.
Visual inspection of the 1-EP-SST-1C was performed. No visual signs of damage or abnormal conditions were observed. No fault pressure relay or mechanical relief device had operated which would have been indicative of an internal fault in the transformer.
Oil samples taken on 1-EP-SST-1C and analyzed by the Dominion Oil Analysis Lab confirmed no abnormal results.
Current traces from the Digital Fault Recorder were analyzed to determine if an actual fault had occurred. Normal load current for the equipment being powered from the 1-EP-SST-1C prior to the event was observed. Normal starting current for manual start of 1-CN-P-1C was observed just prior to the lockout relay actuation (approximately 8 cycles).
The differential relays for 1-EP-SST-1C were tested and determined to be operable.
Corrective and design change work orders were reviewed to ensure work order job steps contain adequate means for tracking configuration control changes, corrected work orders.
6.0 ACTIONS TO PREVENT RECURRENCE Corrective actions are being tracked under root cause evaluation RCE001 110. Corrective actions include: 1) development of a Job Familiarization Guide for planner qualifications, 2) implementation the Job Familiarization Guide for planner qualifications, and 3) revising WM-AA-101 "Work Order Planning" to include notes and/or procedure steps to direct use of configuration control tracking documentation when approved procedures are not available to control configuration.
7.0 SIMILAR EVENTS
None
8.0 ADDITIONAL INFORMATION
Unit 2 was operating in Mode 1,100 percent power on October 11, 2013 and was not affected by this event.
Description
Station Service Transformer (1 -EP-SST-1 C)
Manufacturer: HYOSUNG Corporation (HICO)