05000374/LER-2019-001, Safety Related Electrical Bus Undervoltage Results in Valid Actuation of the Common Emergency Diesel Generator
| ML19119A235 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 04/29/2019 |
| From: | Washko J Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RA19-030 LER 2019-001-00 | |
| Download: ML19119A235 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(iii) 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) |
| 3742019001R00 - NRC Website | |
text
Exelon Generation RA19-030 April 29, 2019 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Unit 2 Renewed Facility Operating License No. NPF-18 NRC Docket No. 50-374 LaSalle County Station 2601 North 21 *1 Road Marseilles, IL 61341 815-415-2000 Telephone www.exeloncorp.com 10 CFR 50.73
Subject:
Licensee Event Report 2019-001-00, Safety Related Electrical Bus Undervoltage Results in Valid Actuation of the Common Emergency Diesel Generator In accordance with 10 CFR 50.73(a)(2)(iv)(A), Exelon Generation Company, LLC (EGC) is submitting Licensee Event Report (LEA) Number 2019-001-00 for LaSalle County Station, Unit 2.
There are no regulatory commitments in this letter. Should you have any questions concerning this report, please contact Mr. Daniel Mearhoff, Regulatory Assurance Manager, at (815) 415-2800.
Respectfully,
~~~
John~Uiko Plant Manager LaSalle County Station
Enclosure:
Licensee Event Report cc:
Regional Administrator-NRC Region Ill NRC Senior Resident Inspector - LaSalle County Station
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LICENSEE EVENT REPORT (LER)
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3.Page LaSalle County Station, Unit 2 05000374 1
OF 3
- 4. Title Safety Related Electrical Bus Undervoltage Results in Valid Actuation of the Common Emergency Diesel Generator
- 5. Event Date
- 6. LER 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 LaSalle County Station, Unit 1 05000373 Facility Name Docket Number 02 28 19 2019 - 001 00 04 29 19 NA NA
- 9. Operating Mode
- 11. This Report is Submitted Pursuant to the Requirements of 10 CFR §:(Check all that apply)
D 20.2201(b)
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 50.73(a)(2)(iii)
D 50. 73(a)(2)(ix)(A)
D 20.2203(a)(2)(i)
D 50.36(c)(1 )(i)(A) 181 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 73.71 (a)(4)
D 20.2203(a)(2)(iii)
D 50.36(c)(2)
D 50.73(a)(2)(v)(B)
D 73.71(a)(5)
D 20.2203(a)(2)(iv)
D 50.46(a)(3)(ii)
D 50.73(a)(2)(v)(C)
D 73.77(a)(1) 000 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(D)
D 73.77(a)(2)(i)
D 20.2203(a)(2)(vi)
D 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 73.77(a)(2)(ii)
D 50.73(a)(2)(i)(C)
D Other (Specify in Abstract below or in
REPORTABILITY AND SAFETY ANALYSIS
SEQUENTIAL NUMBER 001 REV NO.
00 This event was reported on March 1, 2019 (ENS 53903) in accordance with 1 O CFR 50. 72(b)(3)(iv)(A) for a valid specified system actuation. This event is reportable in accordance with 10 CFR 50.73(a){2)(iv)(A), as an event that results in a valid actuation of the emergency AC electrical power system.
Resulting from the 241Y bus trip and 'O' EOG actuation signal, plant responses occurred as designed. Affected systems were restored with no adverse impacts to either unit. Unit 1 remained stable and in MODE 1 during this event. While the affected component, Unit 1 ACB 1414 was inoperable, entries were made into Unit 1 Technical Specifications (TS) 3.8.1, AC Sources-Operating. Specifically, LCO Condition A for one required offsite circuit inoperable, Required Actions A.1, A.2, and A.3 were performed. After completing repairs, each ACB was retested and declared operable, and the station exited associated TS time clocks on March 2, 2019.
CORRECTIVE ACTIONS
Immediate corrective actions taken in response to the condition were:
Shift ensured plant responded safely, entered associated abnormal operating procedures, and made applicable TS entries.
Station initiated troubleshooting to evaluate the event, condition, and make repairs necessary to restore the ACBs to operable.
Corrective actions identified and completed from troubleshooting and the causal investigation were:
Replace degraded lug on Unit 2 ACB 2414 A-phase CT terminal
PREVIOUS OCCURRENCES
Searches were performed of the LaSalle Corrective Action Program (CAP) database, operating experience records, and licensee event reports for the previous three years. No similar previous events or conditions related to the underlying cause were identified.
COMPONENT FAILURE DATA
Device Name: ACB 2414 Unit Tie [2AP04E-1]
Manufacturer: ITE Circuit Breaker LTD [1005]
Component Type: Breaker, Switchgear [S35]
Model: 5HK350 (LAS) Breaker, Circuit, 4.16 KV Page _3_ of _3_