05000352/LER-2017-001, Regarding Condition Prohibited by TS Due to Parts Quality Issue
| ML17027A107 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/27/2017 |
| From: | Libra R Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LG-17-009 LER 17-001-00 | |
| Download: ML17027A107 (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)(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)(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) |
| 3522017001R00 - NRC Website | |
text
Exelon Generation LG-17-009 January 27, 2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Units 1 and 2 Renewed Facility Operating License No. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353 10 CFR 50.73
Subject:
LEA 2017-001-00, Condition Prohibited by TS due to Parts Quality Issue This Licensee Event Report (LEA) addresses a condition prohibited by Technical Specifications (TS) at Limerick Generating Station (LGS) Units 1 and 2 when the Main Control Room (MCA)
HVAC system return and supply fans failed to start on multiple occurrences, causing an unplanned TS entry and inoperability of the associated Control Room Emergency Fresh Air Supply (CREFAS) system. This LEA is being submitted pursuant to the requirements of 50.73(a)(2}(i)(B) for an Operation or Condition Prohibited by TS.
There are no commitments contained in this letter.
If you have any questions, please contact Robert B. Dickinson at (610) 718-3400.
Respectfully, 1Z~~ID~ ~.L*..
Vice President - Limerick Generating Station Exelon Generation Company, LLC cc: Administrator Region I, USNRC USNRC Senior Resident Inspector, LGS
NRC FORM 366 (06-2016)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (06-2016)
LICENSEE EVENT REPORT (LER)
APPROVED BY OMB: 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 Branch (T-5 F53), 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 Limerick Generating Station, Units 1 and 2
- 2. DOCKET NUMBER 05000352 & 05000353
- 3. PAGE 1 OF 3
- 4. TITLE Condition Prohibited by TS due to Parts Quality Issue
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.
MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 11 29 16 2017 - 001
- - 00 01 27 17 FACILITY NAME DOCKET NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(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) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x)
- 10. POWER LEVEL 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 73.71(a)(4) 100 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)(ii) 50.73(a)(2)(v)(C) 73.77(a)(1) 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)(ii) 50.73(a)(2)(i)(C)
OTHER Specify in Abstract below or in Page 3 of 3 III.
Analysis of the Event
The identified relay failures were all determined to be attributed to intermittent drop out, or chattering of the installed Agastat/Tyco model ETR14I3D004 (ETR TDPU series) relay coil.
These relays were all installed as normally energized, power monitoring/ Loss of Offsite Power (LOOP) start relays. They are installed to allow a 35-second time delay before the fan restarts on re-energization of the associated load center during a LOOP.
The testing determined that the relays were not reliable and failure of the relays could not be predicted. The 0B MCR HVAC train was determined to be unreliable since the initial relay replacement on 10/19/16 until when the relays were replaced with relays from a different lot on 12/05/16. The B train of MCR HVAC was conservatively determined to be inoperable for a period of 47 days, which is greater than the allowable LCO action window of 7 days (per TS 3.7.2.a.1) for an inoperable CREFAS train, and therefore was deemed to be a condition prohibited by TS.
IV.
Cause of the Event
Bench tests were performed on-site on the removed relays in addition to failure analysis by an offsite testing facility. This testing determined the cause of the relay chattering to be an incorrectly installed capacitor on the internal timing circuit board.
V.
Corrective Actions Completed/Planned Extent of condition actions were taken to replace all of the Agastat 2016 ETR relays installed at Limerick. A total of two additional relays, from the same lot, were identified to be installed in the plant and both these relays were proactively replaced.
A Part 21 was generated by TE Connectivity for the manufacturing issue. (ML17006A011)
VI.
Previous Similar Occurrences There were no previous similar occurrences in the last five years of MCR Supply fan and Return fan trips due to defective relays.
VII.
Component data:
System:
V Central Control Complex Env. Ctrl. Sys.
Component:
RLY Relay, Time-Delay Starting or Closing Component number: KS-078-326B & KS-078-359B Manufacturer:
T351 Tyco Instrument DIV Model number:
ETR14I3D004