05000395/LER-2013-001, V. C. Summer Nuclear Station, Unit 1, Regarding Grid Disturbance Results in an Engineered Safeguard Features Actuation of the a EDG

V. C. Summer Nuclear Station, Unit 1, Regarding Grid Disturbance Results in an Engineered Safeguard Features Actuation of the a EDG

ML13144A577
Person / Time
Site:	Summer
Issue date:	05/22/2013
From:	Gatlin T South Carolina Electric & Gas Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 13-001-00
Download: ML13144A577 (4)

LER-2013-001, V. C. Summer Nuclear Station, Unit 1, Regarding Grid Disturbance Results in an Engineered Safeguard Features Actuation of the a EDG

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(iv)(B)(8) 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)(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
3952013001R00 - NRC Website

text

Thomas D. Gatlin Vice President, Nuclear Operations 803.345.4342 A SCANA COMPANY May 22, 2013 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555

Dear Sir / Madam:

Subject:

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS), UNIT 1 DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 LICENSEE EVENT REPORT (LER 2013-001-00)

GRID DISTURBANCE RESULTS IN AN ENGINEERED SAFEGUARD FEATURES ACTUATION OF THE "A" EDG Attached is Licensee Event Report (LER) 2013-001-00, for the Virgil C. Summer Nuclear Station (VCSNS). This report describes the grid disturbance that initiated an Engineered Safeguard Features actuation of the "A" Emergency Diesel Generator. This report is submitted in accordance with 10CFR50.73(a)(2)(iv)(A) and 1 OCFR50.73(a)(2)(iv)(B)(8).

Should you have any questions, please call Mr. Bruce Thompson at (803) 931-5042.

Very truly yours, Thomas D. Gatlin JMG/TDG/bq Attachment c:

K. B. Marsh S. A. Byrne J. B. Archie N. S. Carns J. H. Hamilton J. W. Williams W. M. Cherry V. M. McCree E. A. Brown NRC Resident Inspector QA Manager - M. N. Browne Paulette Ledbetter J. C. Mellette EPIX Coordinator K. M. Sutton INPO Records Center Marsh USA, Inc.

Maintenance Rule Engineer NSRC RTS (CR-13-01346)

File (818.07)

PRSF (RC-13-0075)

Virgil C. Summer Station -Post Office Box 88 *Jenkinsville, SC.29065

• F (803) 345-5209 Out-

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)

, the NRC ma%

digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.

3. PAGE V. C. SUMMER NUCLEAR STATION, UNIT 1 05000 395 1

OF

4. TITLE GRID DISTURBANCE RESULTS IN AN ENGINEERED SAFEGUARD FEATURES ACTUATION OF THE "A" EDG

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER NUMBER NO.

05000 FACILITY NAME DOCKET NUMBER 03 24 2013 2013 1

0 05 22 2013 05000

9. OPERATING MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)

MODE 5 E] 20.2201(b)

[]

20.2203(a)(3)(i)

El 50.73(a)(2)(i)(C)

[]

50.73(a)(2)(vii)

E] 20.2201(d)

[] 20.2203(a)(3)(ii) 5 50.73(a)(2)(ii)(A)

E] 50.73(a)(2)(viii)(A)

LI 20.2203(a)(1)

El 20.2203(a)(4)

El 50.73(a)(2)(ii)(B)

E] 50.73(a)(2)(viii)(B)

_[]20.2203(a)(2)(i)

El 50.36(c)(1)(i)(A)

El 50.73(a)(2)(iii) 5 50.73(a)(2)(ix)(A)

10. POWER LEVEL 5

20.2203(a)(2)(ii)

[] 50.36(c)(1)(ii)(A)

[

50.73(a)(2)(iv)(A) j]

50.73(a)(2)(x)

O 20.2203(a)(2)(iii) 5 50.36(c)(2)

El 50.73(a)(2)(v)(A)

El 73.71(a)(4) 0%

El 20.2203(a)(2)(iv) 5 50.46(a)(3)(ii)

El 50.73(a)(2)(v)(B) 5 73.71(a)(5)

O 20.2203(a)(2)(v) 5 50.73(a)(2)(i)(A)

El 50.73(a)(2)(v)(C) 0 OTHER EJ 20.2203(a)(2)(vi)

El 50.73(a)(2)(i)(B)

[]

50.73(a)(2)(v)(D)

Specify in Abstract below or in

4.0 SAFETY SIGNIFICANCE

The safety significance of this event was minimal. The station was in Mode 5 for a mid cycle outage. The grid disturbance caused an undervoltage relay actuation on the 7200 Volt Switchgear Bus (XSWIDA) as designed. This resulted in automatic start of the "A" standby EDG but due to the short undervoltage duration, the relay delay time of the normal incoming breaker did not trip open or initiate the ESFLS. All station equipment and all transmission system equipment operated as designed.

5.0 PREVIOUS OCCURRENCE VCSNS experienced a similar event reported by Event Notification EN#40811 on June 13, 2004 and by letter under Licensee Event Report (LER 2004-002-00) on August 11, 2004. This event was due to a lightning strike on the same 115 kV offsite power source but did result in sequenced loads by ESFLS.

6.0 CORRECTIVE ACTIONS

All station equipment and transient system equipment operated as designed. To prevent the probability of similar events occurring in the future, the Power Delivery Department has been requested to inspect and improve, where necessary, the transmission tower grounding devices on the 115 kV lines. This request has been entered into the station corrective action program.