ML18078A066

LER 2018-001-00 for Virgil C. Summer, Unit 1, Valid Actuation of Emergency Diesel Generator

ML18078A066
Person / Time
Site:
Issue date:	03/19/2018
From:	Lippard G A South Carolina Electric & Gas Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CR-18-00268, RC-18-0021 LER 2018-001-00
Download: ML18078A066 (4)

Text

A SCANA COMPANY George A. Lippard Vice President, Nuclear Operations 803.345.4810 March 19, 2018 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS), UNIT 1 DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 LICENSEE EVENT REPORT (LER 2018-001-00) VALID ACTUATION OF EMERGENCY DIESEL GENERATOR Attached is Licensee Event Report (LER) 2018-001-00, for the Virgil C. Summer Nuclear Station. This report describes the actuation of the A' Emergency Diesel Generator caused by the loss of the 115 kV power supply to the normal incoming Engineered Safety Features power supply to the safety related bus 1DA. This report is submitted in accordance with 10 CFR 50.73(a)(2)(iv)(A). An apparent cause evaluation is being performed. A supplemental LER will be submitted to provide the results of the evaluation. Should you have any questions, please call Mr. Michael S. Moore at (803)345-4752. BAB/GAL/nk Attachment c: J.E. Addison W.K. Kissam J. B. Archie J. H. Hamilton G. J. Lindamood W. M. Cherry C. Haney S. A. Williams NRC Resident Inspector L.W. Harris Paulette Ledbetter J.C. Mellette ICES Coordinator K.M. Sutton INPO Records Center Marsh USA, Inc. Maintenance Rule Engineer NSRC RTS (CR-18-00268) File (818.07) PRSF (RC-18-0021) 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 M i 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.gov/readina-rm/doc-collections/nuregs/staff/sr1022/r3A APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 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. Send comments regarding burden estimate to the Information Services Branch (T-2 F43), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to Infocollects. Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503, If a means used to impose an information collection does not display a currently valid OMB control number, 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 VALID ACTUATION OF EMERGENCY DIESEL GENERATOR 5. EVENT DATE 6. LER NUMBER 7. REPORT DATE 8. OTHER FACILITIES INVOLVED YEAR SEQUENTIAL NUMBER REV NO. FACILITY NAME DOCKET NUMBER 05000 01 18 2018 2018 - 001 00 03 19 2018 FACILITY NAME DOCKET NUMBER 05000 9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) J 20.2201(b) ] 20.2203(a)(3)(i)

• 50.73(a)(2)(ii)(A)

• 50.73(a)(2)(viii)(A) 1 [ 20.2201(d) ] 20.2203(a)(3)(H)

• 50.73(a)(2)(H) (B)

• 50.73(a) (2)(viii)(B) ] 20.2203(a)(1) ] 20.2203(a)(4)

• 50.73(a)(2)(iii)

• 50.73(a)(2)(ix)(A) ] 20.2203(a)(2)(i)

• 50.36(c)(1)(i)(A) [7] 50.73(a)(2)(iv)(A)

• 50.73(a)(2)(x) 10. POWER LEVEL ] 20.2203(a)(2)(H)

• 50.36(c)(1)(ii)(A)

• 50.73(a)(2)(v)(A)

• 73.71(a)(4) ] 20.2203(a)(2)(iii)

• 50.36(c)(2)

• 50.73(a)(2)(v)(B)

• 73.71(a)(5) ] 20.2203(a)(2)(iv)

• 50.46(a)(3)(H)

• 50.73(a)(2)(v)(C)

• 73.77(a)(1) 100 ] 20.2203(a)(2)(v)

• 50.73(a)(2)(i)(A)

• 50.73(a)(2)(v)(D)

• 73.77(a)(2)(i) ^ 20.2203(a)(2)(vi)

• 50.73(a)(2)(i)(B)

• 50.73(a)(2) (vii)

• 73.77(a)(2)(H)

• 50.73(a)(2)(i)(C) OTHER Specify in Abstract below or in NRC Form 366A 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT Michael Moore, Manager Nuclear Licensing TELEPHONE NUMBER (Include Area Code) (803) 345-4752 13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT CAUSE SYSTEM COMPONENT FACTURER REPORTABLE TO EPIX CAUSE SYSTEM COMPONENT FACTURER REPORTABLE TO EPIX NA NA NA NA NA NA NA NA NA NA 14. SUPPLEMENTAL REPORT EXPECTED [7] YES (If yes, complete 15. EXPECTED SUBMISSION DATE) Q NO 15. EXPECTED SUBMISSION DATE MONTH DAY YEAR 14. SUPPLEMENTAL REPORT EXPECTED [7] YES (If yes, complete 15. EXPECTED SUBMISSION DATE) Q NO 15. EXPECTED SUBMISSION DATE 5 07 2018 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) On January 18, 2018 at 1202 [EST], V.C. Summer Nuclear Station (VCSNS) lost one of its two redundant offsite power supplies. The loss of the 115 kV offsite power supply created an undervoltage condition on the normal incoming Engineered Safety Features (ESF) power supply to the safety related bus IDA. The 'A' Emergency Diesel Generator (EDG) started and loads sequenced as designed. All plant equipment and systems responded as expected. All loads were transferred back to the offsite 115 kV power supply at 1318 [EST]. The EDG was secured at 1321 [EST], and reset for auto start. Reactor power remained at 100% throughout the event. An apparent cause evaluation is being performed. A supplemental LER will be submitted to provide the results of the evaluation. NRC FORM 366 (04-2017)

1. FACILITY NAME 2. DOCKET NUMBER 3. LER NUMBER V.C. Summer Nuclear Station, Unit 1 05000-395 YEAR 2018 SEQUENTIAL NUMBER REV NO. V.C. Summer Nuclear Station, Unit 1 05000-395 YEAR 2018 -001 -00 NARRATIVE NRC FORM 366A (04-2017) U.S. NUCLEAR REGULATORY COMMISSION w

• LICENSEE EVENT REPORT (LER) I CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form http://wvwv.nrc.Qov/readina-rm/doc-collections/nureas/staff/sr1022/r3/1 APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 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. Send comments regarding burden estimate to the Information Services Branch (T-2 F43), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection. 1.0 EVENT DESCRIPTION On January 18, 2018 at 1202 [EST], VCSNS lost one of its two redundant offsite power supplies. The Parr Substation supplies the 115 kV offsite power supply to VCSNS. Emergent maintenance at the offsite Parr Substation resulted in an inadvertent opening of breaker #1802 in the Parr Switchyard. The loss of the power supply created an undervoltage condition on the normal incoming ESF power supply to the safety related bus 1DA. The 'A' EDG started and loads sequenced as designed. The 'A' Residual Heat Removal Pump started but did not inject any water into the Reactor Coolant System. The 'A' Emergency Feedwater pump started and ran for approximately 2 minutes. All other plant equipment and systems also responded as expected. The normal power supply for the other required offsite power source remained available throughout the event. Operations personnel monitored the plant and verified conditions were stable prior to realigning the plant to normal feed and securing the EDG. All loads were transferred back to the offsite power supply at 1318 [EST]. The EDG was secured at 1321 [EST], and reset for auto start. 2.0 EVENT ANALYSIS The SCE&G transmission system supplies offsite power for operating the ESF buses as well as for startup and shutdown of the station. One power source is the SCE&G transmission grid terminating at the VCSNS 230 kV switchyard bus, which feeds the plant through a step down transformer. The second power source is from the offsite Parr Generating Complex over a 115 kV transmission line. This source is connected to the plant through onsite step down transformers and a separate regulating transformer. The 7.2 kV ESF buses are each provided with three loss of voltage relays set at approximately 81% of the nominal bus voltage level and three degraded voltage relays set at approximately 91.34% of the nominal bus voltage level. Receipt of an undervoltage signal from the associated bus from either the loss of voltage relays or degraded voltage relays will automatically initiate a diesel generator start, a permissive for EFW turbine pump start, an ESF load sequence operation and a permissive for diesel generator circuit breaker close. Loss of voltage on an ESF bus opens the normal or alternate supply circuit breaker (whichever is closed) and, when emergency diesel generator voltage and frequency are established, closes the emergency power source circuit breaker. The undervoltage and degraded voltage relays associated with 1DA functioned properly upon detecting the loss of voltage on the incoming 115kV line. The 'A' EDG started and all required loads sequenced on as designed. Operators acknowledged alarms and walked down the main control board to ensure equipment was functioning properly. The normal power supply for the other required offsite power source remained available throughout the event. NRC FORM 366A (04-2017) Page 2 of 3 NRC FORM 366A (04-2017) Page 3 of 3