05000338/LER-2014-001, Regarding Engineered Safety Feature Actuations Due to Loss of Power to C Reserve Station Service Transformer
| ML14205A011 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 07/14/2014 |
| From: | Gerald Bichof Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 14-326 LER 14-001-00 | |
| Download: ML14205A011 (4) | |
| 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 |
| 3382014001R00 - NRC Website | |
text
1 0CFR50.73 Virginia Electric and Power Company North Anna Power Station 1022 Haley Drive Mineral, Virginia 23117 July 14, 2014 Attention: Document Control Desk Serial No.:
14-326 U. S. Nuclear Regulatory Commission NAPS:
RAP Washington, DC 20555-0001 Docket No.: 50-338, 50-339 License No.: NPF-4, 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 Units 1 and 2.
Report No. 50-338/2014-001-00 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, Gerald T. Bi6hof 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
- - Vt
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 (02-2014)
(02,20,4)
Estimated burden 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 industry.
M WO*
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections (LER)\\
Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by LICENSEE EVENT~1 REPORT I(J X) internet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and (See Page 2 for required number of Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC rfor each block) 20503. If a means used to impose an information collection does not display a currently valid OMB digits/characters fcontrol number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE North Anna Power Station 05000338 1 OF 3
- 4. TITLE Engineered Safety Feature Actuations Due to Loss of Power to "C" Reserve Station Service Transformer
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MOTH DA YAR IF, SEQUENrr*.
EV MOT DAIYA FACILITY NAME DOCKET NUrMBER MONTH DAY YEAR YEtR R
EV MONTH DAY YEAR North Anna Power Station 05000339 S
I I
IFACILITY NAME DOCKET NUMBER 05 15 2014 2014 001 001 07 14 2014 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
D 20.2201(b)
[
20.2203(a)(3)(i) 50.73(a)(2)(i)(C)
D 50.73(a)(2)(vii)
E 20.2201(d)
[
20.2203(ai(3)(ii) 50.73(a)(2)(ii)(A)
E 50.73(a)(2)(viii)(A)
D 20.2203(a)(1)
[
20.2203(a)(4) 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i)
[
50.36(c)(1)(i)(A) 50.73(a)(2)(iii)
IZ 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)
E 20.2203(a)(2)(iii) 50.36(c)(2)
El 50.73(a)(2)(v)(A) 73.71(a)(4)
IZ 20.2203(a)(2)(iv)
E 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100%
0E 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
[]
50.73(a)(2)(v)(C)
El OTHER 20.2203(a)2)(vi) 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Absrract helow or in
- 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT TELEPHONE NUMBER (Include Area Code)
Gerald T. Bischof, Site Vice President 1(540) 894-2101CAUS SYSTEM COMPONENT MAU CUSE SYSTM CMOET
?LN-RPRAL FACTURER TO EPIX CA OMPONENT FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR SUBMISSION E
YES (If yes. complete 15. EXPECTED SUBMISSION DATE)
Z NO DATE
.BSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced lype**ritten lines)
At 1920 on May 15, 2014, with both Units 1 and 2 operating at 100% power, the load side of switchyard transformer #3 faulted, causing a loss of the "C" Reserve Station Service Transformer (RSST). The cause of the event was due to a crow making contact with Bus #5 "A" phase to ground. The loss of the "C" RSST caused a power loss on the Unit 1 "H" (1H) and the Unit 2 "J" (2J) Emergency busses and the associated Emergency Diesel Generators (EDGs) auto-started and re-energized the busses. In addition, the Unit 2 "A" Charging pump auto-started due to the under-voltage condition on the 2J bus. The pump was secured and returned to auto at 1938 on May 15, 2014. At 2046 on May 15, 2014, offsite power was restored to the 1H Emergency bus and the 1H EDG was secured. At 0410 on May 16, 2014, offsite power had been restored to the 2J Emergency bus and the 2J EDG was secured. This event was reportable per 10CFR50.72(b)(3)(iv)(A) for actuation of an Engineered Safety Feature (ESF) system. The health and safety of the public were not affected by this event.
NRC FORM 366 (02-2014)
'4RC =
1.0 DESCRIPTION OF THE EVENT At 1920 on May 15, 2014, with Units 1 and 2 operating at 100% power, the load side of switchyard transformer (EIIS System - EA, Component - XFMR) #3 faulted, causing a loss of the "C" Reserve Station Service Transformer (RSST) (EIIS System - EA, Component - XFMR). The loss of the "C" RSST caused a power loss on the Unit 1 "H" (1 H) and the Unit 2 "J" (2J) Emergency busses (EIIS System - EK, Component - BU) and the associated Emergency Diesel Generators (EDGs) (EIIS System -EK, Component - DG) auto-started and re-energized the busses. An 8-hour report per 10CFR50.72(b)(3)(iv)(A) was made at 2310 hours0.0267 days <br />0.642 hours <br />0.00382 weeks <br />8.78955e-4 months <br /> on May 15, 2014 for automatic actuation of an Engineered Safety Feature (ESF) system.
At 2046 on May 15, 2014, the 1 H Emergency bus offsite power source was restored and the 1 H EDG was secured.
As a result of the event, the Unit 2 Moisture Separator Reheater (MSR) flow control valves (FCVs) (EIIS System - SB, Component - FCV) went closed and reactor power reduced to 96 percent. In addition, the Unit 2 "A" Charging pump (EIIS System - CB, Component - P) auto-started due to the under-voltage condition on the 2J bus. The pump was secured and returned to auto at 1938 on May 15, 2014. At that same time, the MSR FCVs were reopened and by 2230 on May 15, 2014, power returned to approximately 100 percent. At 0410 on May 16, 2014, the "C" RSST was energized and normal power restored to the 2J Emergency bus and the 2J EDG was secured.
2.0 SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS
No significant safety consequences resulted from this event because the 1 H and 2J EDGs powered the emergency busses, as designed. Offsite power sources were restored in a timely manner and the associated EDGs were secured and returned to automatic. The health and safety of the public were not affected by this event.
3.0 CAUSE
The cause of the event was due to a crow making contact with Bus #5 "A" phase to ground. The Apparent Cause is a less than adequate prevention of a bird, or other animal, from making contact with an open air energized bus to ground.
4.0 IMMEDIATE CORRECTIVE ACTION(S)
The immediate corrective actions were to restore offsite power to the 1 H and 2J Emergency busses. Once offsite power was restored, the 1 H and 2J EDGs were
secured, and all event related TS actions were cleared by 0440 on May 16, 2014.
5.0 ADDITIONAL CORRECTIVE ACTIONS
No additional corrective actions were identified by the Apparent Cause Evaluation.
6.0 ACTIONS TO PREVENT RECURRENCE The fleet and industry standard design is to not have any electrical covers on open air non-insulated electrical conductors/tube bus work. Engineering is evaluating installation of electrical protective covers on susceptible areas of switchyard bus to help prevent future faults from animal contact.
7.0
SIMILAR EVENTS
No similar events have occurred at North Anna Power Station.
8.0 ADDITIONAL INFORMATION
Unit 1 continued operating in Mode 1,100 percent power during this event.