05000338/LER-2018-001, SW-P-1B Failed to Trip During the 1J Blackout Test
| ML18135A080 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 05/09/2018 |
| From: | Lane N Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 2018-001-00 | |
| Download: ML18135A080 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(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)(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) |
| 3382018001R00 - NRC Website | |
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10CFR50.73 Virginia Electric and Power Company North Anna Power Station 1022 Haley Drive Mineral, Virginia 23117 May 9, 2018, Attention: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Dear Sirs:
Serial No.:
18-157 NAPS:
RAP Docket Nos.: 50-338 License Nos.: NPF-4 Pursuant to 1 OCFR50. 73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to North Anna Power Station Unit 1.
Report No. 50-338/2018-001-00 This report has been reviewed by the Facility Safety Review Committee and will be forwarded to the Management Safety Review Committee for its review.
Sincerely,
£L!~
N. Larry Lane Site Vice President North Anna Power Station Enclosure Commitments contained in this letter: None cc:
United States Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, Georgia 30303-1257 NRC Senior Resident Inspector North A.nna Power Station
'., i NRC FORM 366 (11-2015)
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la U.S. NUCLEAR REGULATORY COMMISSIOII APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 10/31/2018 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 FOIA, Privacy and Information Collections
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,..,.1 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, DC digits/characters for each block) 20503. If a means used to impose an information collection does not display a currenfly valid 0MB control number, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE North Anna Power Station, Unit 1 05000338 1 OF 3
- 4. TITLE 1-SW-P-18 Failed to Trip During the 1J Blackout Test
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED YEAR I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO.
MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 03 11 2018 2018 - 001 -
00 05 09 2018 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
D 20.2201 Cb>
D 20.2203(a)(3)(i>
D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A)
D 20.2201 (d>
D 20.2203(a)(3)(ii)
D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B) 5 D 20.2203(a><1 >
D 20.2203(a)(4>
D so.13(a><2><m>
D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(i>
D 50.36(c)(1)(i)(A)
D 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
- 10. POWER LEVEL D 20.2203(a><2>(ii)
D 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(v)(A)
D 13.11(a)(4>
D 20.2203(a><2><m>
D so.3s(c><2>
D 50.73(a)(2)(v)(B)
D 13.11<a>(s>
D 20.2203(a)(2)(iv)
D so.4s(a)(3)(ii)
D 50.73(a)(2)(v)(C)
D 13.77(a>(1>
0 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(D)
D 13.77(a><2>
D 20.2203(a)(2)(vi)
~ 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 13. n(a><2)(ii)
D 50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in NRC Form 366A
- 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT
!TELEPHONE NUMBER (Include Area Code)
Larry Lane, Site Vice President (540) 894-2101 CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX A
Bl WEL y
- 14. SUPPLEMENTAL REPORT EXPECTED 15.EXPECTED MONTH DAY YEAR 0 YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
~NO SUBMISSION DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On March 11, 2018, with Unit 1 at O percent power in mode 5 and Unit 2 at 100 percent power in mode 1, the Unit 1 "B" Service Water (SW) Pump failed to trip during 1J Emergency Bus blackout testing. The pump did not load shed and sequence back on the bus, as expected, but remained energized by the emergency bus during the auto stwt of the 1 J Emergency Diesel Generator (EOG).
This condition was the result of a disconnected wire on sequence timing relay 1-SW-62-1SWEB03 which in turn caused the relay to be inoperable. Investigation of why the wire was disconnected identified the most likely cause to be inadvertent manipulation of the wire during the implementation of an unrelated design change the previous refueling outage. With the inoperable sequence timing relay, this rendered the 1 J EOG inoperable, though it was capable to perform its design function. In addition, redundant equipment was removed from service, including the 1 H EOG for reasons other than normal testing, over the time period the 1 J EOG was inoperable. This is a condition prohibited by Technical Specifications and is reportable in accordance with 10 CFR 50.72(a)(2)(i)(B). The health and safety of the public were not affected by this event.
NRC FORM 366 (11-2015)
I, I...
Page 2 of3 1.0 DESCRIPTION OF THE EVENT On 3/11/2018 while performing 1-PT-83.2, "Simulated Loss of Offsite Power {LOOP) and ESF Actuation" testing, it was determined that the Unit 1 "B" Service Water pump (EIIS System,-81, Component-P), 1-SW-P-18, did not load*shed and sequence back on the bus, but remained energized by the 1 J emergency bus (EIIS System - EA) during auto start of the 1J Emergency Diesel Generator (EOG) (EIIS System - EK, Component -
DG). Investigation identified a disconnected wire from contact C1 on timer relay 1-SW-62-1 SWE803 and the disconnected wire resulted in a "Required sequence timing relay" being inoperable per Technical Specification (TS) Surveillance Requirement (SR) 3.8.1.1_6. This also rendered the 1 J EOG inoperable though it was still capable of performing its design function.
In addition, redundant equipment was: removed from service over the time period the 1 J EOG was inoperable, including the 1 H EOG for reasons other than normal testing.
This is a condition prohibited by Technical Specifications and is reportable in accordance with 10 CFR 50.72(a)(2)(i)(B).
Additionally, the "8" Boric Acid Storage Tank (BAST) (EIIS System - CB, Component -
TK) heater (EIIS System - CB, Component - EHTR), 1-CH:-EHR-078, did not load shed during the test. The associated 42X relay was pulled in and was. bound. The BAST heater is not part of the acceptance criteria for 1-PT-83.2.
2.0 SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS
No significant safety consequences resulted from this event because an Engineering evaluation revealed that the additional loads of 1-SW-P-18 and 1-CH-EHR-078 did not challenge established limits of the 1 J EOG and therefore, the design basis was not exceeded. The health and safety of the public were not affected by this event..*
3.0 CAUSE
The direct cause of 1-SW-P-18 not stripping off and then properly sequencing onto the bus was the disconnected wire from contact C1 on 1-SW-62-1SWE803. The direct cause for 1-CH-EHR-078 from not stripping off the bus was 42X relay being bound.
. The apparent cause for the disconnected wire was inadvertent manipulation of the wire during maintenance activities associated with a design change the week of 9/18/2016.
I,..
Page 3 of 3 (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET North Anna Power Station, Unit 1 05000338 YEAR
- 6. LER NUMBER SEQUENTIAL NUMBER REV NO.
2018 001 00 4.0 IMMEDIATE CORRECTIVE ACTION(S)
The wire was reconnected and the test was completed satisfactorily on 3/12/2018. The 42X relay for' 1-CH-EHR-078 was replaced under work order #59203139375 and tested satisfactorily.
5.0 ADDITIONAL CORRECTIVE ACTIONS
The individuals involved with the design change maintenance activities that occurred the week of 9/18/2016 were provided coaching to be aware of their surroundings* to ensure inadvertent manipulations do not occur. Extent of condition walk downs and inspections were co11ducted for each load sequencing relay for Unit 1 and Unit 2. These inspections were performed based on past NGV modifications performed by NSS and relay sequencing -timer inspections performed by station electricians. No abnormal or unexpected conditions were identified during the performance 'of the walk' downs and inspections 6.0 ACTIONS TO PREVENT RECURRENCE The Nuclear Site Services procedure GMP-E-139, Internal Wiring Package, and Engineering procedure O-GEP-52, Conduct of Post-Modification Testing, will be modified.
to ensure a close out inspection is performed, inspecting for any potential inadvertent manipulation of equipment or wiring in the surrounding work area.
Additionally, the Nuclear Maintenance Manager will monitor Configuration Control Fundamentals under the existing Maintenance Improvement Plan for a period of no less than 6 months and initiate any additional actions needed for performance improvement.
7.0 SIMILAR EVENTS
No similar events have occurred at North Anna.
8.0 MANUFACTURER/MODEL NUMBER N/A
9.0 ADDITIONAL INFORMATION
Unit 2 continued operating at 100 percent power, rnode 1, during this event.