05000281/LER-2015-002, Regarding Unanticipated Start of EDG 2 During Testing

Regarding Unanticipated Start of EDG 2 During Testing

ML15314A661
Person / Time
Site:	Surry
Issue date:	11/04/2015
From:	Lane N Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
15-509 LER 15-002-00
Download: ML15314A661 (5)

LER-2015-002, Regarding Unanticipated Start of EDG 2 During Testing

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) 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
2812015002R00 - NRC Website

text

10OCFR50.73 Virginia Electric and Power Company Surry Power Station 5570 Hog Island Road Surry, Virginia 23883 November 4, 2015 U. S. Nuclear Regulatory Commission Serial No.:

15-509 Attention: Document Control Desk SPS:

JSA Washington, D. C. 20555-0001 Docket No.: 50-281 License No.: DRP-37 Pursuant to I0CFR5O.73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to Surry Power Station Unit 2.

Report No. 50-281/2015-002-00 This report has been reviewed by the Station Facility Safety Review Committee and will be forwarded to the Management Safety Review Committee for its review.

Very truly yours, N. L. Lane Site Vice President Surry Power Station Enclosure Commitment contained in this letter: None cc: U.S. Nuclear Regulatory Commission, Region II Marquis One Tower, Suite 1200 245 Peachtree Center Ave., NE Atlanta, GA 30303-1257 NRC Senior Resident Inspector Surry Power Station

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 0113112017 (02-2014)

,,*,."-*,,,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.

• =Sand comments regarding burden estimate to the FOIA, Privacy and Information Collections LICE SE EVE NT RE PORT (LE R Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by LIC ~~

0

)

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 dgt/hacesfor each block) 20503. If a means used to impose an information collection does not display a currently valid 0MB digis/caracerscontrol number, the NRC may not conduct or sponsor, and a parson is not required'to respond to, the information collection.

13. PAGE Surry Power Station, Unit 2 05000281 1 OF 4

4. TITLE Unanticipated Start of EDG 2 During Testing

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MNH AY YASEUNILRV FACILITY NAME DOCKET NUMBER YER NME 1O MNH DY yA 05000 09 16 205 2015 -

002

- 00 I 1

0 05 FACILITYNAME DOCKET NUMBER050

9. OPERATING MODE

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

E] 20.2201(b)

[] 20.2203(a)(3)(i)

[] 50.73(a)(2)(i)(Ci D] 50.73(a)(2)(vii)

[] 20.2201(d)

[] 20.2203(a)(3)(ii)

[] 50.73(a)(2)(ii)(A)

[] 50.73(a)(2)(Viii)(A)

N D 20.2203(a)(1)

W] 20.2203(a)(4)

LI 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)

LI 50.73(a)(2)(ix)(A)

10. POWER LEVEL LI 20.2203(a)(2)(ii)

LI 50.36(c)(1)(ii)(A)

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

[] 50.73(a)(2)(x)

LI 20.2203(a)(2)(iii)

LI 50.36(c)(2)

LI 50.73(a)(2)(v)(A)

LI 73.71(a)(4)

LI 20.2203(a)(2)(iv)

LI 50.46(a)(3)(ii)

LI 50.73(a)(2)(v)(B)

LI 73.71(a)(5) 10 L

20.2203(a)(2)(v)

[] 50.73(a)(2)(i)(A)

LI 50.73(a)(2)(v)(C)

LI OTHER LI 20.2203(a)(2)(vi)

[]

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

LI 50 73(a)(2)(v)(D)

Specify in Abstract below or in

12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT TELEPHONE NUMBER (Include Area Code)

N. L. Lane, Site Vice President (757) 365-2001I ANU REOTAL LIMN-RPRAL CAUSEB SYSTEME COMPONENTRL FACTURERw 2

TOYEPIX CAU SE SYTE COPNN OTFACTURER D

TO EPIX

14. SUPPLEMENTAL REPORT EXPECTED "15.SUMSSoEXPECTED MNH DY YEAR LI YES (If yes, complete 15. EXPECTED SUBMISSION DATE)

[] NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)

On September 16, 2015, at 2014 hours0.0233 days <br />0.559 hours <br />0.00333 weeks <br />7.66327e-4 months <br /> with Units I and 2 operating at 100 percent power, Emergency Diesel Generator 2 automatically started and assumed power to the Unit 2 'H' emergency bus. The event occurred during quarterly performance of the Emergency Bus Undervoltage and Degraded Voltage Protection Test. The direct cause of the event was the defective "A" single phase relay sticking and preventing the relay contacts from changing state. The procedures for Emergency Bus Undervoltage and Degraded Voltage Protection Tests have been revised to physically validate the state of the emergency bus relays prior to testing additional relays. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(iv)(A) for valid actuation of an EmergenCy Diesel Generator.

NRC FORM 366 (02-2014)

1.0 DESCRIPTION OF THE EVENT The purpose of the Emergency Bus Undervoltage and Degraded Voltage Protection Test is to provide quarterly testing of undervoltage and degraded voltage protection schemes of the emergency bus trains as required by Surry Technical Specifications.

The Undervoltage Protection Channels consist of three individual single phase relays [EIIS-ED-RLY]. These relays provide input to a two out of three coincident relay logic for operation. One of the functions of the undervoltage circuits is to sense a loss of voltage condition and place the respective emergency bus on the Emergency Diesel Generator (EDG) [EIIS-EK-DG].

On September 16, 2015, at 2014 hours0.0233 days <br />0.559 hours <br />0.00333 weeks <br />7.66327e-4 months <br /> with Units 1 and 2 operating at 100 percent power, an undervoltage signal was generated during performance of the Emergency Bus Undervoltage and Degraded Voltage Protection Test. As a result, EDG 2 started and loaded as designed on the Unit 2 'H' emergency bus.

During performance of the test, the 'A' phase undervoltage portion of the test was successfully completed and an indication light verified that 'A' phase was left in its normal energized condition. At 2014 hours0.0233 days <br />0.559 hours <br />0.00333 weeks <br />7.66327e-4 months <br />, when testing of the 'B' phase began, a undervoltage signal was generated and EDG 2 started and assumed the load of the Unit 2 'H' emergency bus. The test was terminated and operations initiated the abnormal procedure for loss of the Unit 2 'H' emergency bus. At 2216 hours0.0256 days <br />0.616 hours <br />0.00366 weeks <br />8.43188e-4 months <br /> on September 17, 2015, normal source power was restored to the 'H' bus and EDG 2 was unloaded, taken offline and placed back in automatic at 2244 hours0.026 days <br />0.623 hours <br />0.00371 weeks <br />8.53842e-4 months <br /> on September 17, 2015.

On September 17, 2015 at 0027 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br />, an event notification was made to the NRC in accordance with 10 CFR 50.72(b)(3)(iv)(A) for valid actuation of EDG 2 following loss of the Unit 2 'H' emergency bus during performance of the Emergency Bus Undervoltage and Degraded Protection Test.

This report is being submitted, pursuant to, 10 CFR 50.73(a)(2)(iv)(A), for automatic actuation of the EDG.

2.0

SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS

This event resulted in no safety consequences or implications. Appropriate operator actions were taken in accordance with abnormal operating procedures and the unit remained at 100 percent power. Station equipment was available and responded as designed. Therefore, the health and safety of the public were not affected.

NRC FORM 385A (02-201.4)

3.0

CAUSE

Troubleshooting determined that upon completion of the 'A' phase undervoltage test, the 'A' single phase relay did not reset. However, an indication light verified that 'A' phase was in its normal powered condition. Therefore, when the 'B' phase undervoltage test began and the 'B' phase relay was deenergized, the two out of three coincident logic was met resulting in the normal power supply breaker to the 'H' bus to open, as designed. EDG 2 started and loaded as designed on the Unit 2 'H' emergency bus.

The direct cause of the 'A' single phase relay not resetting was debris and warping in the relay slug chamber and signs of heat damage. These conditions prevented smooth movement of the relay slug in the chamber and resulted in it sticking and preventing the relay contacts from changing state.

The apparent cause of the undervoltage signal and resultant loss of the Unit 2 'H' emergency bus was a procedural deficiency that relied upon a light indication of power to the relay but did not verify the position of the relay after each step of the undervoltage test.

4.0 IMMEDIATE CORRECTIVE ACTION(S)

Normal offsite power was restored to the 'H' bus at 2216 hours0.0256 days <br />0.616 hours <br />0.00366 weeks <br />8.43188e-4 months <br /> on September 17, 2015 and EDG 2 was unloaded, taken offline and placed back in automatic. The failed relay was replaced.

5.0

ADDITIONAL CORRECTIVE ACTIONS

An apparent cause evaluation was completed to investigate the event.

6.0 ACTIONS TO PREVENT RECURRENCE The procedures for Emergency Bus Undervoltage and Degraded Voltage Protection Tests have been revised to physically validate the state of the emergency bus relaYs to ensure the two out of three logics will not be satisfied if a relay fails to energize.

7.0

SIMILAR EVENTS

None 8.0 MANUFACTURER/MODEL NUMBER Westinghouse/ARD440U R NRC FORM 366 (02-2014)

9.0

ADDITIONAL INFORMATION

Unit 1 was at 100% power and remained unaffected by the starting of EDO 2.

NRC FORM 366 (02-2014)

10OCFR50.73 Virginia Electric and Power Company Surry Power Station 5570 Hog Island Road Surry, Virginia 23883 November 4, 2015 U. S. Nuclear Regulatory Commission Serial No.:

15-509 Attention: Document Control Desk SPS:

JSA Washington, D. C. 20555-0001 Docket No.: 50-281 License No.: DRP-37 Pursuant to I0CFR5O.73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to Surry Power Station Unit 2.

Report No. 50-281/2015-002-00 This report has been reviewed by the Station Facility Safety Review Committee and will be forwarded to the Management Safety Review Committee for its review.

Very truly yours, N. L. Lane Site Vice President Surry Power Station Enclosure Commitment contained in this letter: None cc: U.S. Nuclear Regulatory Commission, Region II Marquis One Tower, Suite 1200 245 Peachtree Center Ave., NE Atlanta, GA 30303-1257 NRC Senior Resident Inspector Surry Power Station

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 0113112017 (02-2014)

,,*,."-*,,,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.

• =Sand comments regarding burden estimate to the FOIA, Privacy and Information Collections LICE SE EVE NT RE PORT (LE R Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by LIC ~~

0

)

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 dgt/hacesfor each block) 20503. If a means used to impose an information collection does not display a currently valid 0MB digis/caracerscontrol number, the NRC may not conduct or sponsor, and a parson is not required'to respond to, the information collection.

13. PAGE Surry Power Station, Unit 2 05000281 1 OF 4

4. TITLE Unanticipated Start of EDG 2 During Testing

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MNH AY YASEUNILRV FACILITY NAME DOCKET NUMBER YER NME 1O MNH DY yA 05000 09 16 205 2015 -

002

- 00 I 1

0 05 FACILITYNAME DOCKET NUMBER050

9. OPERATING MODE

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

E] 20.2201(b)

[] 20.2203(a)(3)(i)

[] 50.73(a)(2)(i)(Ci D] 50.73(a)(2)(vii)

[] 20.2201(d)

[] 20.2203(a)(3)(ii)

[] 50.73(a)(2)(ii)(A)

[] 50.73(a)(2)(Viii)(A)

N D 20.2203(a)(1)

W] 20.2203(a)(4)

LI 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)

LI 50.73(a)(2)(ix)(A)

10. POWER LEVEL LI 20.2203(a)(2)(ii)

LI 50.36(c)(1)(ii)(A)

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

[] 50.73(a)(2)(x)

LI 20.2203(a)(2)(iii)

LI 50.36(c)(2)

LI 50.73(a)(2)(v)(A)

LI 73.71(a)(4)

LI 20.2203(a)(2)(iv)

LI 50.46(a)(3)(ii)

LI 50.73(a)(2)(v)(B)

LI 73.71(a)(5) 10 L

20.2203(a)(2)(v)

[] 50.73(a)(2)(i)(A)

LI 50.73(a)(2)(v)(C)

LI OTHER LI 20.2203(a)(2)(vi)

[]

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

LI 50 73(a)(2)(v)(D)

Specify in Abstract below or in

12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT TELEPHONE NUMBER (Include Area Code)

N. L. Lane, Site Vice President (757) 365-2001I ANU REOTAL LIMN-RPRAL CAUSEB SYSTEME COMPONENTRL FACTURERw 2

TOYEPIX CAU SE SYTE COPNN OTFACTURER D

TO EPIX

14. SUPPLEMENTAL REPORT EXPECTED "15.SUMSSoEXPECTED MNH DY YEAR LI YES (If yes, complete 15. EXPECTED SUBMISSION DATE)

[] NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)

On September 16, 2015, at 2014 hours0.0233 days <br />0.559 hours <br />0.00333 weeks <br />7.66327e-4 months <br /> with Units I and 2 operating at 100 percent power, Emergency Diesel Generator 2 automatically started and assumed power to the Unit 2 'H' emergency bus. The event occurred during quarterly performance of the Emergency Bus Undervoltage and Degraded Voltage Protection Test. The direct cause of the event was the defective "A" single phase relay sticking and preventing the relay contacts from changing state. The procedures for Emergency Bus Undervoltage and Degraded Voltage Protection Tests have been revised to physically validate the state of the emergency bus relays prior to testing additional relays. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(iv)(A) for valid actuation of an EmergenCy Diesel Generator.

NRC FORM 366 (02-2014)

1.0 DESCRIPTION OF THE EVENT The purpose of the Emergency Bus Undervoltage and Degraded Voltage Protection Test is to provide quarterly testing of undervoltage and degraded voltage protection schemes of the emergency bus trains as required by Surry Technical Specifications.

The Undervoltage Protection Channels consist of three individual single phase relays [EIIS-ED-RLY]. These relays provide input to a two out of three coincident relay logic for operation. One of the functions of the undervoltage circuits is to sense a loss of voltage condition and place the respective emergency bus on the Emergency Diesel Generator (EDG) [EIIS-EK-DG].

On September 16, 2015, at 2014 hours0.0233 days <br />0.559 hours <br />0.00333 weeks <br />7.66327e-4 months <br /> with Units 1 and 2 operating at 100 percent power, an undervoltage signal was generated during performance of the Emergency Bus Undervoltage and Degraded Voltage Protection Test. As a result, EDG 2 started and loaded as designed on the Unit 2 'H' emergency bus.

During performance of the test, the 'A' phase undervoltage portion of the test was successfully completed and an indication light verified that 'A' phase was left in its normal energized condition. At 2014 hours0.0233 days <br />0.559 hours <br />0.00333 weeks <br />7.66327e-4 months <br />, when testing of the 'B' phase began, a undervoltage signal was generated and EDG 2 started and assumed the load of the Unit 2 'H' emergency bus. The test was terminated and operations initiated the abnormal procedure for loss of the Unit 2 'H' emergency bus. At 2216 hours0.0256 days <br />0.616 hours <br />0.00366 weeks <br />8.43188e-4 months <br /> on September 17, 2015, normal source power was restored to the 'H' bus and EDG 2 was unloaded, taken offline and placed back in automatic at 2244 hours0.026 days <br />0.623 hours <br />0.00371 weeks <br />8.53842e-4 months <br /> on September 17, 2015.

On September 17, 2015 at 0027 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br />, an event notification was made to the NRC in accordance with 10 CFR 50.72(b)(3)(iv)(A) for valid actuation of EDG 2 following loss of the Unit 2 'H' emergency bus during performance of the Emergency Bus Undervoltage and Degraded Protection Test.

This report is being submitted, pursuant to, 10 CFR 50.73(a)(2)(iv)(A), for automatic actuation of the EDG.

2.0

SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS

This event resulted in no safety consequences or implications. Appropriate operator actions were taken in accordance with abnormal operating procedures and the unit remained at 100 percent power. Station equipment was available and responded as designed. Therefore, the health and safety of the public were not affected.

NRC FORM 385A (02-201.4)

3.0

CAUSE

Troubleshooting determined that upon completion of the 'A' phase undervoltage test, the 'A' single phase relay did not reset. However, an indication light verified that 'A' phase was in its normal powered condition. Therefore, when the 'B' phase undervoltage test began and the 'B' phase relay was deenergized, the two out of three coincident logic was met resulting in the normal power supply breaker to the 'H' bus to open, as designed. EDG 2 started and loaded as designed on the Unit 2 'H' emergency bus.

The direct cause of the 'A' single phase relay not resetting was debris and warping in the relay slug chamber and signs of heat damage. These conditions prevented smooth movement of the relay slug in the chamber and resulted in it sticking and preventing the relay contacts from changing state.

The apparent cause of the undervoltage signal and resultant loss of the Unit 2 'H' emergency bus was a procedural deficiency that relied upon a light indication of power to the relay but did not verify the position of the relay after each step of the undervoltage test.

4.0 IMMEDIATE CORRECTIVE ACTION(S)

Normal offsite power was restored to the 'H' bus at 2216 hours0.0256 days <br />0.616 hours <br />0.00366 weeks <br />8.43188e-4 months <br /> on September 17, 2015 and EDG 2 was unloaded, taken offline and placed back in automatic. The failed relay was replaced.

5.0

ADDITIONAL CORRECTIVE ACTIONS

An apparent cause evaluation was completed to investigate the event.

6.0 ACTIONS TO PREVENT RECURRENCE The procedures for Emergency Bus Undervoltage and Degraded Voltage Protection Tests have been revised to physically validate the state of the emergency bus relaYs to ensure the two out of three logics will not be satisfied if a relay fails to energize.

7.0

SIMILAR EVENTS

None 8.0 MANUFACTURER/MODEL NUMBER Westinghouse/ARD440U R NRC FORM 366 (02-2014)

9.0

ADDITIONAL INFORMATION

Unit 1 was at 100% power and remained unaffected by the starting of EDO 2.

NRC FORM 366 (02-2014)