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{{Adams
#REDIRECT [[05000324/LER-2016-002]]
| number = ML16132A076
| issue date = 05/02/2016
| title = LER 16-002-00 for Brunswick Steam Electric Plant (Bsep), Units 1 and 2, Regarding Emergency Diesel Generator 3 Inoperable Due to Failure to Auto-Start
| author name = Gideon W R
| author affiliation = Duke Energy Progress, Inc
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000324, 05000325
| license number = DPR-062, DPR-071
| contact person =
| case reference number = BSEP 16-0030
| document report number = LER 16-002-00
| document type = Letter, Licensee Event Report (LER)
| page count = 9
}}
 
=Text=
{{#Wiki_filter:May 2, 2016 Serial: BSEP 16-0030 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
 
==Subject:==
Brunswick Steam Electric Plant, Unit Nos. 1 and 2 Renewed Facility Operating License Nos. DPR-71 and DPR-62 Docket No. 50-325 and 50-324 Licensee Event Report 1-2016-002 William R. Gideon Vice President Brunswick Nuclear Plant P.O. Box 10429 Southport, NC 28461 o: 910.457 .3698 10 CFR 50.73 In accordance with the Code of Federal Regulations, Title 10, Part 50.73, Duke Energy Progress, Inc., submits the enclosed Licensee Event Report (LER). This report fulfills the requirement for a written report within sixty (60) days of a reportable occurrence.
This document contains no regulatory commitments.
Please refer any questions regarding this submittal to Mr. Lee Grzeck, Manager -Regulatory Affairs, at (910) 457-2487.
SincqdL vi William R. Gideon :.,...--MAT/mat
 
==Enclosure:==
 
Licensee Event Report U.S. Nuclear Regulatory Commission Page 2 of 2 cc (with enclosure):
U. S. Nuclear Regulatory Commission, Region II ATTN: Ms. Catherine Haney, Regional Administrator 245 Peachtree Center Ave, NE, Suite 1200 Atlanta, GA 30303-1257 U.S. Nuclear Regulatory Commission ATTN: Ms. Michelle P. Catts, NRC Senior Resident Inspector (Electronic Copy Only) 8470 River Road Southport, NC 28461-8869 U.S. Nuclear Regulatory Commission ATTN: Mr. Andrew Hon (Mail Stop OWFN 8G9A) (Electronic Copy Only) 11555 Rockville Pike Rockville, MD 20852-2738 Chair -North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-0510 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMS: NO. 3150-0104 EXPIRES: 10/31/2018 (11-2015)
Estimated burden per response to comply with this mandatory collection request: 80 hours. " .. Reported lessons learned are incorporated into the licensing process and fed back to industry . ; . Send comments regarding burden estimate to the FOIA, Privacy and Information Collections
.. f LICENSEE EVENT REPORT (LER) Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by ...-,.+., *****
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, digits/characters for each block) DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. PAGE Brunswick Steam Electric Plant (BSEP), Unit 1 05000325 1 OF 7 4. TITLE Emergency Diesel Generator 3 Inoperable Due to Failure to Auto-Start
: 5. EVENT DATE 6. LEA NUMBER 7. REPORT DATE 8. OTHER FACILITIES INVOLVED I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO. MONTH DAY YEAR BSEP, Unit2 05000324 FACILITY NAME DOCKET NUMBER 03 04 2016 2016 -002 -00 05 02 2016 05000 9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (CheckaHthatapply)
D 20.2201(bl D 20.2203(a)(3)(il D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A) 5 D 20.2201 (dl D 20.2203(a)(3)(iil D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B)
D 20.2203(a)(1 l D 20.2203(a)(4l D so.13(a)(2)(iiil D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(il D 50.36(c)(1
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D 50.73(a)(2)(x)
: 10. POWER LEVEL D 20.2203(aJ(2J(iiJ D 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(v)(A)
D 13.11 (aJ(4J D 20.2203(a)(2J(mJ D so.3s(c)(2J D 50.73(a)(2)(v)(B)
D 13.11(aJ(sJ D 20.2203(a)(2)(iv)
D so.4s(aJ(3J(iiJ D 50.73(a)(2)(v)(C)
D 13.11(a)(1J 000 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
[8J 50.73(a)(2)(v)(D)
D 13.11(aJ(2J(iJ D 20.2203(a)(2)(vi)
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D OTHER Specify in Abstract below or in NRG Form 366A 12. LICENSEE CONTACT FOR THIS LEA LICENSEE CONTACT rELEPHONE NUMBER (Include Area Code) Lee Grzeck, Manager -Regulatory Affairs (910) 457-2487 13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT CAUSE SYSTEM COMPONENT MANU-REPORTABLE
.** CAUSE SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX ,. FACTURER TO EPIX x EK FUB B569 y .. 14. SUPPLEMENTAL REPORT EXPECTED 15.EXPECTED MONTH DAY YEAR 0 YES (If yes, complete 15. EXPECTED SUBMISSION DATE) [8J NO SUBMISSION DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) On March 4, 2016, at 1235 Eastern Standard Time (EST), Emergency Diesel Generator (EOG) 3 was declared inoperable.
At this time, EDG 1, Emergency bus E1, and balance of plant (BOP) bus 1 D were inoperable due to planned maintenance.
Two inoperable EDGs represents a loss of safety function, for the onsite standby power source. Therefore, this condition is being reported in accordance with 10 CFR 50.73{a){2){v)(D), as an event or condition that could have prevented the fulfillment of the safety function of a system that is needed to mitigate the consequences of an accident.
In addition, it was determined that EOG 3 was inoperable for greater than Technical Specifications
{TSs) Completion Times. Therefore, this condition is also being reported in accordance with 10 CFR 50.73(a){2)(i)(B) as operation prohibited by the TSs. Additionally, on March 3, work was ongoing to restore power to BOP bus 1 D when an error in the restoration sequence resulted in an invalid auto-start of EDGs 2 and 4. Because the invalid auto-starts of EDGs 2 and 4 are directly related to the events associated with this LER, it is being reported, herein, per 10 CFR 50.73{a){2)(iv)(A) rather than the optional 60-day telephone notification.
The root cause of the EOG 3 inoperability is inadequate training for the use of non-conductive fuse clearance devices. Corrective actions to prevent recurrence include actions to upgrade training and procedures associated with fuse standards.
NRG FORM 366 (11-2015)
Page2of7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: BO hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch {T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to lnlocollects.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 NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. LER NUMBER Brunswick Steam Electric Plant (BSEP), Unit 1 05000-325 YEAR SEQUENTIAL NUMBER REV NO. 2016 -002 NARRATIVE Energy Industry Identification System (EllS) codes are identified in the text as [XX]. Background Initial Conditions At the time of this event, Unit 1 was in Mode 5 (i.e., Refuel), in a refueling outage which began on February 26, 2016. Unit 2 was in Mode 1 (i.e., Power Operation) with reactor power at approximately 100 percent of rated thermal power. Emergency Diesel Generator 1 (EOG 1) [EK] was inoperable in support of modifications, maintenance activities, and testing. Emergency bus E1 [EB] and balance of plant (BOP) bus 1 D were deenergized in support of this work. No other Unit 2 safety-related equipment was inoperable.
Reportability Criteria 10 CFR 50.73(a)(2)(v)(D) 00 Brunswick EOG capacity is such that any three of the four diesels can supply the required loads for the safe shutdown of one unit and a design basis accident on the other unit without offsite power. As such, simultaneous inoperability of EDGs 1and3 is reportable in accordance with 10 CFR 50.73(a)(2)(v)(D), as an event or condition that could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident.
The NRG was initially notified of the event on March 4, 2016 (i.e., Event Number 51769). As discussed below, it has been determined that EOG 3 was inoperable from February 7, 2016, until March 4, 2016. During this time, EDGs 1, 2, a,nd 4 were also inoperable, at various times, for surveillance testing and associated activities.
These occurrences are also reportable in accordance with 10 CFR 50.73(a)(2)(v)(D), as an event or condition that could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident.
Event Number 51769 also reported loss of safety function of the Conventional Service Water system [Bl], the Control Room Emergency Ventilation system [VI], and the Control Room Air Condition system [VI]. After additional review, it has been determined that a loss of safety function of these systems did not occur. As such, this event is not reportable per 10 CFR 50.72(b)(3)(v) or 10 CFR 50.73(a)(2)(v) for those systems. 10 CFR 50.73(a)(2)(i)(B)
This event is reportable in accordance with 1 O CFR 50.73(a)(2)(i)(B) as operation prohibited by the plant's Technical Specifications (TSs) for both Unit 1 and Unit 2. The following conditions resulted in unintentional operation prohibited by the plant's TSs given the inoperability of EOG 3. NRG FORM 366A (11-2015)
Page 3 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150*0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet 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 NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. LEA NUMBER Brunswick Steam Electric Plant (BSEP), Unit 1 05000-325 YEAR SEQUENTIAL NUMBER REV NO. 2016 -002 NARRATIVE
* On February 8, 2016, at 2211 Eastern Standard Time (EST), Unit 2 would have been required to be in Mode 3 in accordance with TS 3.8.1, Required Action H.1, for one offsite circuit inoperable and one EOG inoperable (i.e., TS 3.8.1, Condition F).
* On February 12, 2016, at 2357 EST, Unit 1 entered Mode 2 from Mode 4. This constituted a violation of Limiting Condition for Operation (LCO) 3.0.4.
* On February 20, 2016, at 1157 EST, Unit 1 would have been required to be in Mode 3 in accordance with TS 3.8.1, Required Action H.1, for a single EOG inoperable (i.e., TS 3.8.1, Condition D).
* On February 21, 2016, at 0806 EST, Unit 1 and Unit 2 would have been required to be in Mode 3 in accordance with TS 3.8.1, Required Action H.1, for two EDGs inoperable (i.e., TS 3.8.1, Condition G). 00
* On March 3, 2016, at 2108 EST, Unit 2 would have been required to be in Mode 2 in accordance with LCO 3.0.3, per TS 3.8.1, Condition I, (i.e., one or more offsite circuits and two or more Diesel Generators (DGs) inoperable).
10 CFR 50.73(a)(2)(iv)(A)
On March 3, work was ongoing to restore power to BOP bus 1 D when an error in the restoration sequence resulted in an invalid auto-start of EDGs 2 and 4 at 1332 EST. EDGs 2 and 4 responded properly to the auto-start signal and ran unloaded.
Since no actual bus under voltage condition existed which required the EDGs to start, and the start was not in response to actual plant conditions satisfying the requirements . for initiation, this event has been classified as an invalid actuation.
Because the invalid auto-starts of EDGs 2 and 4 are directly related to the events associated with this LER, the event is being reported via this LER rather than the optional 60-day telephone notification as allowed by 1 O CFR 50.73(a)(1
). Event Description On March 2, at 1458 EST, EOG 1 was declared inoperable in support of modifications, maintenance activities, and testing. Emergency bus E1 and balance of plant (BOP) bus 1 D were deenergized in support of this work. This was a planned maintenance activity, being performed during the ongoing Unit 1 refueling outage. Due to the shared electrical distribution system at Brunswick, Unit 2 was in TS 3.8.1, Condition B (i.e., two Unit 1 offsite circuits inoperable due to one Unit 1 balance of plant circuit path to the downstream 4.16 kV emergency bus inoperable for planned maintenance and the EOG associated with the affected downstream 4.16 kV emergency bus inoperable for planned maintenance).
On March 3, work was ongoing to restore power to BOP bus 1 D when an error in the restoration sequence resulted in an invalid auto-start of EDGs 2 and 4. The invalid signal mimicked undervoltage on the startup auxiliary transformer (SAT) [EA], which is not a TS required start and, per design, would have started EDGs 1, 2, 3, and 4. EOG 1 was under clearance and, as such, did not start. However, it was also expected that EOG 3 should have started. Troubleshooting activities and a thorough EOG 1 modification review were initiated.
As a result, on March 4, 2016, at 1235 hours EST, it was determined that continuity was lost across a dummy fuse block in the auto-start circuitry for EOG 3. This failure prevented TS required auto-actuation of EOG 3. Therefore, EOG 3 was declared inoperable.
At this Unit 2 NRC FORM 366A (11-2015)
Page 4 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collecfion request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of lnfonmation 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 NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME Brunswick Steam Electric Plant (BSEP), Unit 1 NARRATIVE
: 2. DOCKET NUMBER YEAR 05000-325 2016 -3. LEA NUMBER SEQUENTIAL NUMBER 002 REV NO. 00 entered TS 3.8.1, Condition I, (i.e., one or more offsite circuits and two or more Diesel Generators (DGs) inoperable).
Required Action 1.1 directs immediate entry into LCO 3.0.3. Duke Energy Progress, Inc., verbally requested a Notice of Enforcement Discretion (NOED) to extend the time required by LCO 3.0.3 for Unit 2 to be in Mode 2, Mode 3, and Mode 4 by 17 hours. The NRC verbally approved the NOED at 1535 EST on March 4, 2016. EOG 3 was restored to operable status and LCO 3.0.3 was exited at 1834 EST after replacement of the fuse holder. This was before the original Completion Time of LCO 3.0.3 (i.e., be in Mode 2 by March 4, 2016, at 1935 EST). As a result of the root cause evaluation of this event, the direct cause of the EOG 3 failure to auto-start was identified as a loss of continuity in the 2-DG3-FU-1-ECR Dummy Fuse at EOG 3 Emergency Control Relay (ECR) Disconnect; specifically, lom;;e fuse clamps in the dummy fuse block/holder.
Further, there is firm evidence that this condition existed since February 7, 2016, when EOG 3 successfully auto-started in response to a Unit 1 SAT lock-out condition, the details of which are discussed in Brunswick LER 1-2016-001, dated April 6, 2016. On February 7, operators observed that the auto-start indications for EOG 3 (i.e., annunciator UA-21 5-2, and lights) had cleared, without operator action. This provides indication that the loss of continuity in the dummy fuse holder occurred at that time. The unexpected clearing indicates a loss of power to the ECR relay, the same failure mechanism that prevented EOG 3 auto-start on March 3. Therefore, it is concluded that the equipment issue was present from February 7 until March 4, when the fuse holder was replaced.
lnoperability of EOG 3 was determined to be from 2211 EST on February 7, when the EOG 3 was secured from the auto-start, until 1834 EST on March 4, 2016, following replacement of the faulty fuse holder. A review was performed to determine instances when EDGs 1, 2, or 4 were inoperable during the period from February 7, 20.16, until March 4, 2016. The following instances were identified.
Note, the times provided are approximate, based on Operations Log entries. EOG 1 February 20 at 1806 EST to March 2 at 1226 EST (i.e., 10 days, 18 hours, 20 minutes) for planned replacement of the automatic voltage regulator and margin improvement modifications.
March 2 at 1458 EST to March 9 at 0151 EST (i.e., 6 days, 10 hours, 53 minutes) for Division 1 electrical outage and DG 1 governor modification.
Note that EOG 3 was restored to operable status at 1834 EST on March 4. EDG2 February 19 from 2025 EST to 2053 EST (i.e., 28 minutes) for barring. February 19 from 2104 EST to February 20 at 0014 EST (i.e., 3 hours, 10 minutes) for surveillance testing. NRC FORM 366A (11-2015)
Page 5 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT {LEA} CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet 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 NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. LEA NUMBER Brunswick Steam Electric Plant (BSEP), Unit 1 NARRATIVE EDG4 05000-325 YEAR 2016 -SEQUENTIAL NUMBER 002 February 15 from 1235 EST to 1434 EST (i.e., 1 hour, 59 minutes) for surveillance testing. February 18 from 2106 EST to 2140 EST (i.e., 34 minutes) for barring. REV NO. 00 February 18 from 2154 EST to February 19 at 0119 EST (i.e., 3 hours, 25 minutes) for surveillance testing. During the above periods, Unit 2 was in Mode 1. Unit 1 was in Mode 1 until February 26 at 2129 when Mode 3 was entered to start the refueling outage. Event Cause The root cause of this event was determined to be inadequate training for the use of non-conductive fuse clearance devices. The direct cause for the EOG 3 failure to start was determined to be a loss of continuity through a dummy fuse in the auto-start logic circuit for EOG 3, which prevented the ECR coil from being energized and thus starting the diesel. The loss of continuity through the ECR fuse block assembly was a result of loose fuse holder fingers. *The fuse holder fingers became loose due to repeated use of oversized non-conductive fuse clearance devices during routine safety clearance performances.
The dummy fuse and fuse block holder serve as an intermediate clearance point. The dummy fuse is routinely removed per operations procedures when clearances are required and a non-conductive fuse clearance device is installed to prevent insertion of a fuse when a clearance is hanging. The fuse clearance device *has four fuse plugs and the size of each replicated fuse plug is not labeled. When the clearance is being hung, neither the clearance hang sheet nor the fuse lockout device are marked to indicate which fuse plug size should be used. Based on interviews, operations personnel have used the largest of the four fuse plugs when hanging the clearance that pulls the EOG ECR relay dummy fuse. The proper fuse plug to use in this application is the third largest. As a result, the dummy fuse holder fingers have relaxed over time, no longer holding the dummy fuse tightly. Safety Assessment The safety significance of this event is minimal. On March 3, 2016, BOP Bus 1 D, E1, E5, and EDG 1 were inoperable due to ongoing maintenance (i.e., Unit 1 Division 1 AC outage window). The planned Unit 1 maintenance activity had been properly risk assessed prior to the beginning of the outage. The unplanned inoperability of EOG 3 had minimal impact on Unit 1. EOG 3/E3 are primarily associated with Unit 2 loads. A loss of power to E3 could have impacted the 1A Residual Heat Removal (RHR) pump [BO] and the 1A RHR Service Water (SW) pump [BO]. However, on March 3, Unit 1 was flooded up with the spent fuel pool gates removed. Time to boil was approximately 19 hours. Per TS 3.9.7, one RHR shutdown cooling subsystem is required to be operable and in operation in Mode 5 with irradiated fuel in the Reactor Pressure Vessel (RPV) and the NRG FORM 366A (11-2015)
Page 6 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMS: NO. 3150*0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: BO hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and lnlormation Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet 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 inlormation collection does not display a currently valid OMB control number, the NRG may not conduct or sponsor, and a person is not required to respond to, the inlormation collection.
: 1. FACILITY NAME Brunswick Steam Electric Plant (BSEP), Unit 1 NARRATIVE
: 2. DOCKET NUMBER 05000-325 YEAR 2016 -3. LEA NUMBER SEQUENTIAL NUMBER 002 water level greater than or equal to 21 feet 1 O inches above the RPV flange. The primary means of shutdown cooling was B RHR with D RHR the backup. Additionally, EOG 3 could be manually started. Based on these considerations, the event is of minimal safety significance for Unit 1. REV NO. 00 On March 3, 2016, Unit 2 remained in Mode 1. EOG 2, EOG 4, and offsite power sources (i.e., excluding offsite power to emergency bus E1) were not affected by the EOG 1 maintenance and were operable.
Emergency buses E2, E3, and E4 continued to be powered from offsite power. As such, sufficient offsite power supplies remained available to complete their intended safety function.
The Supplemental Diesel Generator (SUPP-DG), installed to support a 14-day completion time for an inoperable EOG, remained available, as well as the two permanently installed FLEX diesels. The SUPP-DG is rated at 4000 kW, 4160 VAC, and can provide power to the emergency busses in approximately 1 hour. Each FLEX diesel is rated' at 500 kW, 480 VAC, and can be connected to the emergency busses in less than one hour. Except for the periods of time for repair activities and post-repair testing, EOG 3 was available via manual start. A Probabilistic Risk Assessment (PRA) was performed to determine the impact of EOG 3 being inoperable from February 7 until March 4, 2016. This analysis concluded that this was of very low safety significance.
Corrective Actions Any changes to the corrective actions and schedules noted below will be made in accordance with the site's corrective action program. The following corrective actions to prevent recurrence have been completed or are planned.
* The Qualification Checkout Card (QCC) for Maintenance and Operations clearance taggers was revised to include On-The-Job Training and Task Performance Evaluation (OJTff PE) for fuse standards.
This was completed on April 4, 2016.
* Operational experience and lessons learned regarding this event and fuse standards will be provided to appropriate Operations personnel.
This is currently scheduled to be completed by May 12, 2016. * "Clearance
& Tagging Training" (i.e., TTC1709-N) was revised to include fuse standards.
This was eompleted on April 16, 2016. In addition, the following corrective actions have been completed or are planned.
* EOG 3 was restored to operable status on March 4, 2016, after replacement of the degraded dummy fuse holder. The dummy fuse holders for EDGs 1, 2, and 4 will be replaced.
This is currently scheduled to be completed by October 1 O, 2016.
* Procedure AD-OP-ALL-0200, "Clearance and Tagging," will be revised to ensure blocking devices that are too large for the fuse clip are not used. This is currently scheduled to be completed by August 31, 2016. NRC FORM 366A (11-2015)
Page 7 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOJA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet 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. FACILITY NAME 2. DOCKET NUMBER 3. LEA NUMBER Brunswick Steam Electric Plant (BSEP), Unit 1 NARRATIVE Previous Similar Events 05000-325 YEAR 2016 -SEQUENTIAL NUMBER 002 A review of LERs for the past five years identified the following previous similar occurrence.
REV NO. 00
* LER 1-2015-002, Revision 1, dated November 11, 2015, reported loss of safety function due to inoperability of EDGs 3 and 4. The root cause of the event was a procedural inadequacy in the commercial grade dedication process that allowed an unauthorized component modification to go unrecognized.
To prevent recurrence of a similar event, procedure AD-EG-ALL-1103, "Procurement Engineering Products," was revised. Since the causes of the events were different, the actions from LER 1-2015-002 could not have reasonably been expected to prevent the condition reported in LER 1-2016-002.
Commitments No regulatory commitments are contained in this report. NRG FORM 366A (11-2015)
May 2, 2016 Serial: BSEP 16-0030 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
 
==Subject:==
Brunswick Steam Electric Plant, Unit Nos. 1 and 2 Renewed Facility Operating License Nos. DPR-71 and DPR-62 Docket No. 50-325 and 50-324 Licensee Event Report 1-2016-002 William R. Gideon Vice President Brunswick Nuclear Plant P.O. Box 10429 Southport, NC 28461 o: 910.457 .3698 10 CFR 50.73 In accordance with the Code of Federal Regulations, Title 10, Part 50.73, Duke Energy Progress, Inc., submits the enclosed Licensee Event Report (LER). This report fulfills the requirement for a written report within sixty (60) days of a reportable occurrence.
This document contains no regulatory commitments.
Please refer any questions regarding this submittal to Mr. Lee Grzeck, Manager -Regulatory Affairs, at (910) 457-2487.
SincqdL vi William R. Gideon :.,...--MAT/mat
 
==Enclosure:==
 
Licensee Event Report U.S. Nuclear Regulatory Commission Page 2 of 2 cc (with enclosure):
U. S. Nuclear Regulatory Commission, Region II ATTN: Ms. Catherine Haney, Regional Administrator 245 Peachtree Center Ave, NE, Suite 1200 Atlanta, GA 30303-1257 U.S. Nuclear Regulatory Commission ATTN: Ms. Michelle P. Catts, NRC Senior Resident Inspector (Electronic Copy Only) 8470 River Road Southport, NC 28461-8869 U.S. Nuclear Regulatory Commission ATTN: Mr. Andrew Hon (Mail Stop OWFN 8G9A) (Electronic Copy Only) 11555 Rockville Pike Rockville, MD 20852-2738 Chair -North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-0510 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMS: NO. 3150-0104 EXPIRES: 10/31/2018 (11-2015)
Estimated burden per response to comply with this mandatory collection request: 80 hours. " .. Reported lessons learned are incorporated into the licensing process and fed back to industry . ; . Send comments regarding burden estimate to the FOIA, Privacy and Information Collections
.. f LICENSEE EVENT REPORT (LER) Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by ...-,.+., *****
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, digits/characters for each block) DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. PAGE Brunswick Steam Electric Plant (BSEP), Unit 1 05000325 1 OF 7 4. TITLE Emergency Diesel Generator 3 Inoperable Due to Failure to Auto-Start
: 5. EVENT DATE 6. LEA NUMBER 7. REPORT DATE 8. OTHER FACILITIES INVOLVED I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO. MONTH DAY YEAR BSEP, Unit2 05000324 FACILITY NAME DOCKET NUMBER 03 04 2016 2016 -002 -00 05 02 2016 05000 9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (CheckaHthatapply)
D 20.2201(bl D 20.2203(a)(3)(il D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A) 5 D 20.2201 (dl D 20.2203(a)(3)(iil D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B)
D 20.2203(a)(1 l D 20.2203(a)(4l D so.13(a)(2)(iiil D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(il D 50.36(c)(1
)(i)(A) [8J 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
: 10. POWER LEVEL D 20.2203(aJ(2J(iiJ D 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(v)(A)
D 13.11 (aJ(4J D 20.2203(a)(2J(mJ D so.3s(c)(2J D 50.73(a)(2)(v)(B)
D 13.11(aJ(sJ D 20.2203(a)(2)(iv)
D so.4s(aJ(3J(iiJ D 50.73(a)(2)(v)(C)
D 13.11(a)(1J 000 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
[8J 50.73(a)(2)(v)(D)
D 13.11(aJ(2J(iJ D 20.2203(a)(2)(vi)
[8J 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 13.11(a)(2)(iiJ
,.,z,"' .. * *. ;11;, z,t: 'i .** D 50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in NRG Form 366A 12. LICENSEE CONTACT FOR THIS LEA LICENSEE CONTACT rELEPHONE NUMBER (Include Area Code) Lee Grzeck, Manager -Regulatory Affairs (910) 457-2487 13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT CAUSE SYSTEM COMPONENT MANU-REPORTABLE
.** CAUSE SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX ,. FACTURER TO EPIX x EK FUB B569 y .. 14. SUPPLEMENTAL REPORT EXPECTED 15.EXPECTED MONTH DAY YEAR 0 YES (If yes, complete 15. EXPECTED SUBMISSION DATE) [8J NO SUBMISSION DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) On March 4, 2016, at 1235 Eastern Standard Time (EST), Emergency Diesel Generator (EOG) 3 was declared inoperable.
At this time, EDG 1, Emergency bus E1, and balance of plant (BOP) bus 1 D were inoperable due to planned maintenance.
Two inoperable EDGs represents a loss of safety function, for the onsite standby power source. Therefore, this condition is being reported in accordance with 10 CFR 50.73{a){2){v)(D), as an event or condition that could have prevented the fulfillment of the safety function of a system that is needed to mitigate the consequences of an accident.
In addition, it was determined that EOG 3 was inoperable for greater than Technical Specifications
{TSs) Completion Times. Therefore, this condition is also being reported in accordance with 10 CFR 50.73(a){2)(i)(B) as operation prohibited by the TSs. Additionally, on March 3, work was ongoing to restore power to BOP bus 1 D when an error in the restoration sequence resulted in an invalid auto-start of EDGs 2 and 4. Because the invalid auto-starts of EDGs 2 and 4 are directly related to the events associated with this LER, it is being reported, herein, per 10 CFR 50.73{a){2)(iv)(A) rather than the optional 60-day telephone notification.
The root cause of the EOG 3 inoperability is inadequate training for the use of non-conductive fuse clearance devices. Corrective actions to prevent recurrence include actions to upgrade training and procedures associated with fuse standards.
NRG FORM 366 (11-2015)
Page2of7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: BO hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch {T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to lnlocollects.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 NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. LER NUMBER Brunswick Steam Electric Plant (BSEP), Unit 1 05000-325 YEAR SEQUENTIAL NUMBER REV NO. 2016 -002 NARRATIVE Energy Industry Identification System (EllS) codes are identified in the text as [XX]. Background Initial Conditions At the time of this event, Unit 1 was in Mode 5 (i.e., Refuel), in a refueling outage which began on February 26, 2016. Unit 2 was in Mode 1 (i.e., Power Operation) with reactor power at approximately 100 percent of rated thermal power. Emergency Diesel Generator 1 (EOG 1) [EK] was inoperable in support of modifications, maintenance activities, and testing. Emergency bus E1 [EB] and balance of plant (BOP) bus 1 D were deenergized in support of this work. No other Unit 2 safety-related equipment was inoperable.
Reportability Criteria 10 CFR 50.73(a)(2)(v)(D) 00 Brunswick EOG capacity is such that any three of the four diesels can supply the required loads for the safe shutdown of one unit and a design basis accident on the other unit without offsite power. As such, simultaneous inoperability of EDGs 1and3 is reportable in accordance with 10 CFR 50.73(a)(2)(v)(D), as an event or condition that could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident.
The NRG was initially notified of the event on March 4, 2016 (i.e., Event Number 51769). As discussed below, it has been determined that EOG 3 was inoperable from February 7, 2016, until March 4, 2016. During this time, EDGs 1, 2, a,nd 4 were also inoperable, at various times, for surveillance testing and associated activities.
These occurrences are also reportable in accordance with 10 CFR 50.73(a)(2)(v)(D), as an event or condition that could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident.
Event Number 51769 also reported loss of safety function of the Conventional Service Water system [Bl], the Control Room Emergency Ventilation system [VI], and the Control Room Air Condition system [VI]. After additional review, it has been determined that a loss of safety function of these systems did not occur. As such, this event is not reportable per 10 CFR 50.72(b)(3)(v) or 10 CFR 50.73(a)(2)(v) for those systems. 10 CFR 50.73(a)(2)(i)(B)
This event is reportable in accordance with 1 O CFR 50.73(a)(2)(i)(B) as operation prohibited by the plant's Technical Specifications (TSs) for both Unit 1 and Unit 2. The following conditions resulted in unintentional operation prohibited by the plant's TSs given the inoperability of EOG 3. NRG FORM 366A (11-2015)
Page 3 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150*0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet 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 NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. LEA NUMBER Brunswick Steam Electric Plant (BSEP), Unit 1 05000-325 YEAR SEQUENTIAL NUMBER REV NO. 2016 -002 NARRATIVE
* On February 8, 2016, at 2211 Eastern Standard Time (EST), Unit 2 would have been required to be in Mode 3 in accordance with TS 3.8.1, Required Action H.1, for one offsite circuit inoperable and one EOG inoperable (i.e., TS 3.8.1, Condition F).
* On February 12, 2016, at 2357 EST, Unit 1 entered Mode 2 from Mode 4. This constituted a violation of Limiting Condition for Operation (LCO) 3.0.4.
* On February 20, 2016, at 1157 EST, Unit 1 would have been required to be in Mode 3 in accordance with TS 3.8.1, Required Action H.1, for a single EOG inoperable (i.e., TS 3.8.1, Condition D).
* On February 21, 2016, at 0806 EST, Unit 1 and Unit 2 would have been required to be in Mode 3 in accordance with TS 3.8.1, Required Action H.1, for two EDGs inoperable (i.e., TS 3.8.1, Condition G). 00
* On March 3, 2016, at 2108 EST, Unit 2 would have been required to be in Mode 2 in accordance with LCO 3.0.3, per TS 3.8.1, Condition I, (i.e., one or more offsite circuits and two or more Diesel Generators (DGs) inoperable).
10 CFR 50.73(a)(2)(iv)(A)
On March 3, work was ongoing to restore power to BOP bus 1 D when an error in the restoration sequence resulted in an invalid auto-start of EDGs 2 and 4 at 1332 EST. EDGs 2 and 4 responded properly to the auto-start signal and ran unloaded.
Since no actual bus under voltage condition existed which required the EDGs to start, and the start was not in response to actual plant conditions satisfying the requirements . for initiation, this event has been classified as an invalid actuation.
Because the invalid auto-starts of EDGs 2 and 4 are directly related to the events associated with this LER, the event is being reported via this LER rather than the optional 60-day telephone notification as allowed by 1 O CFR 50.73(a)(1
). Event Description On March 2, at 1458 EST, EOG 1 was declared inoperable in support of modifications, maintenance activities, and testing. Emergency bus E1 and balance of plant (BOP) bus 1 D were deenergized in support of this work. This was a planned maintenance activity, being performed during the ongoing Unit 1 refueling outage. Due to the shared electrical distribution system at Brunswick, Unit 2 was in TS 3.8.1, Condition B (i.e., two Unit 1 offsite circuits inoperable due to one Unit 1 balance of plant circuit path to the downstream 4.16 kV emergency bus inoperable for planned maintenance and the EOG associated with the affected downstream 4.16 kV emergency bus inoperable for planned maintenance).
On March 3, work was ongoing to restore power to BOP bus 1 D when an error in the restoration sequence resulted in an invalid auto-start of EDGs 2 and 4. The invalid signal mimicked undervoltage on the startup auxiliary transformer (SAT) [EA], which is not a TS required start and, per design, would have started EDGs 1, 2, 3, and 4. EOG 1 was under clearance and, as such, did not start. However, it was also expected that EOG 3 should have started. Troubleshooting activities and a thorough EOG 1 modification review were initiated.
As a result, on March 4, 2016, at 1235 hours EST, it was determined that continuity was lost across a dummy fuse block in the auto-start circuitry for EOG 3. This failure prevented TS required auto-actuation of EOG 3. Therefore, EOG 3 was declared inoperable.
At this Unit 2 NRC FORM 366A (11-2015)
Page 4 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collecfion request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of lnfonmation 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 NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME Brunswick Steam Electric Plant (BSEP), Unit 1 NARRATIVE
: 2. DOCKET NUMBER YEAR 05000-325 2016 -3. LEA NUMBER SEQUENTIAL NUMBER 002 REV NO. 00 entered TS 3.8.1, Condition I, (i.e., one or more offsite circuits and two or more Diesel Generators (DGs) inoperable).
Required Action 1.1 directs immediate entry into LCO 3.0.3. Duke Energy Progress, Inc., verbally requested a Notice of Enforcement Discretion (NOED) to extend the time required by LCO 3.0.3 for Unit 2 to be in Mode 2, Mode 3, and Mode 4 by 17 hours. The NRC verbally approved the NOED at 1535 EST on March 4, 2016. EOG 3 was restored to operable status and LCO 3.0.3 was exited at 1834 EST after replacement of the fuse holder. This was before the original Completion Time of LCO 3.0.3 (i.e., be in Mode 2 by March 4, 2016, at 1935 EST). As a result of the root cause evaluation of this event, the direct cause of the EOG 3 failure to auto-start was identified as a loss of continuity in the 2-DG3-FU-1-ECR Dummy Fuse at EOG 3 Emergency Control Relay (ECR) Disconnect; specifically, lom;;e fuse clamps in the dummy fuse block/holder.
Further, there is firm evidence that this condition existed since February 7, 2016, when EOG 3 successfully auto-started in response to a Unit 1 SAT lock-out condition, the details of which are discussed in Brunswick LER 1-2016-001, dated April 6, 2016. On February 7, operators observed that the auto-start indications for EOG 3 (i.e., annunciator UA-21 5-2, and lights) had cleared, without operator action. This provides indication that the loss of continuity in the dummy fuse holder occurred at that time. The unexpected clearing indicates a loss of power to the ECR relay, the same failure mechanism that prevented EOG 3 auto-start on March 3. Therefore, it is concluded that the equipment issue was present from February 7 until March 4, when the fuse holder was replaced.
lnoperability of EOG 3 was determined to be from 2211 EST on February 7, when the EOG 3 was secured from the auto-start, until 1834 EST on March 4, 2016, following replacement of the faulty fuse holder. A review was performed to determine instances when EDGs 1, 2, or 4 were inoperable during the period from February 7, 20.16, until March 4, 2016. The following instances were identified.
Note, the times provided are approximate, based on Operations Log entries. EOG 1 February 20 at 1806 EST to March 2 at 1226 EST (i.e., 10 days, 18 hours, 20 minutes) for planned replacement of the automatic voltage regulator and margin improvement modifications.
March 2 at 1458 EST to March 9 at 0151 EST (i.e., 6 days, 10 hours, 53 minutes) for Division 1 electrical outage and DG 1 governor modification.
Note that EOG 3 was restored to operable status at 1834 EST on March 4. EDG2 February 19 from 2025 EST to 2053 EST (i.e., 28 minutes) for barring. February 19 from 2104 EST to February 20 at 0014 EST (i.e., 3 hours, 10 minutes) for surveillance testing. NRC FORM 366A (11-2015)
Page 5 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT {LEA} CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet 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 NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. LEA NUMBER Brunswick Steam Electric Plant (BSEP), Unit 1 NARRATIVE EDG4 05000-325 YEAR 2016 -SEQUENTIAL NUMBER 002 February 15 from 1235 EST to 1434 EST (i.e., 1 hour, 59 minutes) for surveillance testing. February 18 from 2106 EST to 2140 EST (i.e., 34 minutes) for barring. REV NO. 00 February 18 from 2154 EST to February 19 at 0119 EST (i.e., 3 hours, 25 minutes) for surveillance testing. During the above periods, Unit 2 was in Mode 1. Unit 1 was in Mode 1 until February 26 at 2129 when Mode 3 was entered to start the refueling outage. Event Cause The root cause of this event was determined to be inadequate training for the use of non-conductive fuse clearance devices. The direct cause for the EOG 3 failure to start was determined to be a loss of continuity through a dummy fuse in the auto-start logic circuit for EOG 3, which prevented the ECR coil from being energized and thus starting the diesel. The loss of continuity through the ECR fuse block assembly was a result of loose fuse holder fingers. *The fuse holder fingers became loose due to repeated use of oversized non-conductive fuse clearance devices during routine safety clearance performances.
The dummy fuse and fuse block holder serve as an intermediate clearance point. The dummy fuse is routinely removed per operations procedures when clearances are required and a non-conductive fuse clearance device is installed to prevent insertion of a fuse when a clearance is hanging. The fuse clearance device *has four fuse plugs and the size of each replicated fuse plug is not labeled. When the clearance is being hung, neither the clearance hang sheet nor the fuse lockout device are marked to indicate which fuse plug size should be used. Based on interviews, operations personnel have used the largest of the four fuse plugs when hanging the clearance that pulls the EOG ECR relay dummy fuse. The proper fuse plug to use in this application is the third largest. As a result, the dummy fuse holder fingers have relaxed over time, no longer holding the dummy fuse tightly. Safety Assessment The safety significance of this event is minimal. On March 3, 2016, BOP Bus 1 D, E1, E5, and EDG 1 were inoperable due to ongoing maintenance (i.e., Unit 1 Division 1 AC outage window). The planned Unit 1 maintenance activity had been properly risk assessed prior to the beginning of the outage. The unplanned inoperability of EOG 3 had minimal impact on Unit 1. EOG 3/E3 are primarily associated with Unit 2 loads. A loss of power to E3 could have impacted the 1A Residual Heat Removal (RHR) pump [BO] and the 1A RHR Service Water (SW) pump [BO]. However, on March 3, Unit 1 was flooded up with the spent fuel pool gates removed. Time to boil was approximately 19 hours. Per TS 3.9.7, one RHR shutdown cooling subsystem is required to be operable and in operation in Mode 5 with irradiated fuel in the Reactor Pressure Vessel (RPV) and the NRG FORM 366A (11-2015)
Page 6 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMS: NO. 3150*0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: BO hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and lnlormation Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet 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 inlormation collection does not display a currently valid OMB control number, the NRG may not conduct or sponsor, and a person is not required to respond to, the inlormation collection.
: 1. FACILITY NAME Brunswick Steam Electric Plant (BSEP), Unit 1 NARRATIVE
: 2. DOCKET NUMBER 05000-325 YEAR 2016 -3. LEA NUMBER SEQUENTIAL NUMBER 002 water level greater than or equal to 21 feet 1 O inches above the RPV flange. The primary means of shutdown cooling was B RHR with D RHR the backup. Additionally, EOG 3 could be manually started. Based on these considerations, the event is of minimal safety significance for Unit 1. REV NO. 00 On March 3, 2016, Unit 2 remained in Mode 1. EOG 2, EOG 4, and offsite power sources (i.e., excluding offsite power to emergency bus E1) were not affected by the EOG 1 maintenance and were operable.
Emergency buses E2, E3, and E4 continued to be powered from offsite power. As such, sufficient offsite power supplies remained available to complete their intended safety function.
The Supplemental Diesel Generator (SUPP-DG), installed to support a 14-day completion time for an inoperable EOG, remained available, as well as the two permanently installed FLEX diesels. The SUPP-DG is rated at 4000 kW, 4160 VAC, and can provide power to the emergency busses in approximately 1 hour. Each FLEX diesel is rated' at 500 kW, 480 VAC, and can be connected to the emergency busses in less than one hour. Except for the periods of time for repair activities and post-repair testing, EOG 3 was available via manual start. A Probabilistic Risk Assessment (PRA) was performed to determine the impact of EOG 3 being inoperable from February 7 until March 4, 2016. This analysis concluded that this was of very low safety significance.
Corrective Actions Any changes to the corrective actions and schedules noted below will be made in accordance with the site's corrective action program. The following corrective actions to prevent recurrence have been completed or are planned.
* The Qualification Checkout Card (QCC) for Maintenance and Operations clearance taggers was revised to include On-The-Job Training and Task Performance Evaluation (OJTff PE) for fuse standards.
This was completed on April 4, 2016.
* Operational experience and lessons learned regarding this event and fuse standards will be provided to appropriate Operations personnel.
This is currently scheduled to be completed by May 12, 2016. * "Clearance
& Tagging Training" (i.e., TTC1709-N) was revised to include fuse standards.
This was eompleted on April 16, 2016. In addition, the following corrective actions have been completed or are planned.
* EOG 3 was restored to operable status on March 4, 2016, after replacement of the degraded dummy fuse holder. The dummy fuse holders for EDGs 1, 2, and 4 will be replaced.
This is currently scheduled to be completed by October 1 O, 2016.
* Procedure AD-OP-ALL-0200, "Clearance and Tagging," will be revised to ensure blocking devices that are too large for the fuse clip are not used. This is currently scheduled to be completed by August 31, 2016. NRC FORM 366A (11-2015)
Page 7 of 7 NRC FORM 366A (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER) CONTINUATION SHEET Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOJA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet 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. FACILITY NAME 2. DOCKET NUMBER 3. LEA NUMBER Brunswick Steam Electric Plant (BSEP), Unit 1 NARRATIVE Previous Similar Events 05000-325 YEAR 2016 -SEQUENTIAL NUMBER 002 A review of LERs for the past five years identified the following previous similar occurrence.
REV NO. 00
* LER 1-2015-002, Revision 1, dated November 11, 2015, reported loss of safety function due to inoperability of EDGs 3 and 4. The root cause of the event was a procedural inadequacy in the commercial grade dedication process that allowed an unauthorized component modification to go unrecognized.
To prevent recurrence of a similar event, procedure AD-EG-ALL-1103, "Procurement Engineering Products," was revised. Since the causes of the events were different, the actions from LER 1-2015-002 could not have reasonably been expected to prevent the condition reported in LER 1-2016-002.
Commitments No regulatory commitments are contained in this report. NRG FORM 366A (11-2015)}}

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