05000395/LER-1917-004, Regarding Actuation of a Emergency Diesel Generator
| ML17313B092 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 11/09/2017 |
| From: | Lippard G South Carolina Electric & Gas Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RC-17-0158 LER 17-004-00 | |
| Download: ML17313B092 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 3951917004R00 - NRC Website | |
text
A SCANA COMPANY George A. Lippard Vice President, Nuclear Operations 803.345.4810 November 09, 2017 RC-17-0158 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 2017-004-00)
ACTUATION OF 'A' EMERGENCY DIESEL GENERATOR Attached is Licensee Event Report (LER) 2017-004-00, for the Virgil C. Summer Nuclear Station. This report describes the actuation of the 'A' emergency diesel generator caused by a perturbation on the off-site electrical system. This report is submitted in accordance with 10 CFR 50.73(a)(2)(iv)(A).
Should you have any questions, please call Mr. Bruce Thompson at (803) 931-5042.
Very truly yours, NRK/GAL/ts Attachment c:
K. B. Marsh S. A. Byrne J. B. Archie N. S. Cams J. H. Flamilton G. J. Lindamood W. M. Cherry C. Haney George A. Lippard S. A. Williams Resident Inspector L. W. Harris Paulette Ledbetter J. C. Mellette ICES Coordinator K. M. Sutton INPO Records Center Marsh USA, Inc.
PRSF (RC-17-0158)
Maintenance Rule Engineer NSRC RTS (CR-17-04897)
File (818.07)
V. C. Summer Nuclear Station
- P. 0. Box 88
- Jenkinsville, South Carolina
- 29065
- F (803) 941-9776
- www.sceg.com
NRC FORM 366 (04-2017)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
(See Page 2 for required number of digits/characters for each block)
(See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.aov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME V.C. Summer Nuclear Station, Unit 1
- 2. DOCKET NUMBER 05000 395
- 3. PAGE 1 OF
- 4. TITLE ACTUATION OF 'A' EMERGENCY DIESEL GENERATOR
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR SEQUENTIAL REV YtAK NUMBER NO.
MONTH DAY YEAR FACILITY NAME N/A DOCKET NUMBER 05000 09 11 2017 2017 -
004 00 11 09 2017 FACILITY NAME N/A DOCKET NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 Q 20.2201(b)
Q 20.2203(a)(3)(i) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 1 Q 20.2201(d)
Q 20.2203(a)(3)(H) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 1
[~~l 20.2203(a)(1) l~~l 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 1 Q 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 0 50.73(a)(2)(iv)(A) 50.73(a)(2)(x)
- 10. POWER LEVEL 100 l l 20.2203(a)(2)(H) 50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 73.71(a)(4)
- 10. POWER LEVEL 100 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(B) 73.71(a)(5)
- 10. POWER LEVEL 100 Q 20.2203(a)(2)(iv) 50.46(a)(3)(H) 50.73(a)(2)(v)(C) 73.77(a)(1)
- 10. POWER LEVEL 100 Q 20.2203(a) (2) (v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(D) 73.77(a)(2)(i)
- 10. POWER LEVEL 100 Q 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(vii) 73.77(a)(2)(H)
- 10. POWER LEVEL 100 50.73(a)(2)(i)(C) l l OTHER Specify in Abstract below or in NRC Form 366A
- 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT Bruce Thompson, Manager Nuclear Licensing TELEPHONE NUMBER (Include Area Code)
(803) 931-5042 CAUSE SYSTEM COMPONENT MANU FACTURER REPORTABLE *...
TO EPIX l§§ OAUbb SYSTEM COMPONENT MANU FACTURER REPORTABLE TO EPIX NA NA NA NA NA NA NA NA NA NA
- 14. SUPPLEMENTAL REPORT EXPECTED l l YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
[/] NO
- 15. EXPECTED SUBMISSION DATE MONTH DAY YEAR
- 14. SUPPLEMENTAL REPORT EXPECTED l l YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
[/] NO
- 15. EXPECTED SUBMISSION DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On September 11, 2017 at 1648, the VCSNS Unit 1 'A' emergency diesel generator (EDG) was actuated. VCSNS Unit 1 was and continued to operate in Mode 1 at 100% reactor power. The EDG actuation was caused by a storm induced perturbation on the off-site power system. The duration of the fault was longer than it should have been due to a malfunction of a transmission system relay. The perturbation cleared and off-site voltage was returned to normal within the designed recovery time limit. The bus continued to be carried by the off-site source and the EDG output breaker remained open.
The station review of this event has shown that plant response was as designed and that no safety consequences occurred.
NRC FORM 366 (04-2017)
1.0 EVENT DESCRIPTION
At 1648 on September 11, 2017, VCSNS Unit 1 was operating in Mode 1 at 100% reactor power when a storm induced perturbation on the off-site power system occurred which resulted in reduced voltage on the 1DA vital bus. The 'A' emergency diesel generator (EDG) started on loss of voltage signal, but it did not load since the low voltage condition cleared within the designed recovery time limit.
A fault on the Killian-Pineland 115kV line occurred as a result of high winds from hurricane Irma. The fault resulted in depressed voltages on both the 115kV and 230kV systems. The duration of the fault was longer than it should have been due to a malfunction of a transmission system relay.
There were two reasons for the delayed clearing of the fault. First, the high speed relay communication scheme on the Killian-Pineland line failed. Second, the relay incorrectly interpreted the fault as a power swing condition and blocked the tripping function that would have cleared the fault.
The 'A' EDG was returned to standby at approximately 1742.
2.0 EVENT ANALYSIS
The EDGs automatically start upon receipt of an undervoltage signal from the associated bus from either the loss of voltage relays or degraded voltage relays, or upon receipt of a safety injection signal. The 7.2 kV ESF buses are each provided with 3 loss of voltage relays set at approximately 81% of the nominal bus voltage level and 3 degraded voltage relays set at approximately 91% of the nominal bus voltage level. Operation of a set of loss of voltage or degraded voltage relays will initiate a diesel generator start.
All three XSW1DA loss of voltage relays sensed a 3-phase fault on the Killian-Pineland 115kV line caused by high winds from hurricane Irma. The voltage remained less than 81% on all three phases for greater than 0.25 seconds resulting in the 'A' EDG starting. Following the diesel start signal, a time delay relay allows 2 seconds for the voltage to recover prior to initiating the load sequencer. Voltage recovered to greater than 81% 1.55 seconds after the 'A' EDG started. Because the sequencer did not initiate, XSW1DA offsite feeder breakers did not open, the diesel output breaker did not close, and loads did not sequence onto the bus.
3.0 SAFETY SIGNIFICANCE
Since plant equipment responded as designed, there was no PRA risk impact from this event. This event had no effect on baseline Core Damage Frequency or Large Early Release Frequency.
4.0 PREVIOUS OCCURRENCE No previous occurrence within the last three years. Page 2
of 3 Page 3
of 3