05000277/LER-2018-002, Unit 3, Emergency Diesel Generator Air Inlet Check Valve Failure Results in a Condition Prohibited by Technical Specifications

Unit 3, Emergency Diesel Generator Air Inlet Check Valve Failure Results in a Condition Prohibited by Technical Specifications

ML18222A326
Person / Time
Site:	Peach Bottom
Issue date:	08/10/2018
From:	Henry D Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CCN: 18-76 LER 2018-002-00
Download: ML18222A326 (4)

LER-2018-002, Unit 3, Emergency Diesel Generator Air Inlet Check Valve Failure Results in a Condition Prohibited by Technical Specifications

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)(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)
2772018002R00 - NRC Website

text

Exelon Generation CCN: 18-76 August 10, 2018 U. S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555-0001 10CFR 50.73 Peach Bottom Atomic Power Station (PBAPS) Unit 2 and Unit 3 Renewed Facility Operating License No. DPR-44 and DPR-56 NRC Docket No. 50-277 and 50-278

Subject:

Licensee Event Report (LER) 2-18-002 Enclosed is a Licensee Event Report concerning a violation of Technical Specifications caused by a failure of an Emergency Diesel Generator. In accordance with NEI 99-04, the regulatory commitment contained in this correspondence is to restore compliance with the regulations.

The specific methods that have been planned to restore and maintain compliance are discussed in the LER.

If you have any questions or require additional information, please do not hesitate to contact Jim Kovalchick at 717-456-3351.

Sincerely,

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Henry Director Site Operations Peach Bottom Atomic Power Station DAH/dnd/IR 4146926 Enclosure cc:

US NRC, Administrator, Region I US NRC, Senior Resident Inspector R. R. Janati, Commonwealth of Pennsylvania S. Gray, State of Maryland B. Watkins, PSE&G, Financial Controls and Co-Owner Affairs

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2018)

Estinated burden per response to comply wit11 th~ mandatory collection request: BO hours.

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LICENSEE EVENT REPORT (LER)

Reported lessoos learned are incorporated '1to the licensing process and led back m industry. Send comments regarding burden estinete to the Information Services Branch

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(See Page 2 for required number of digits/characters for each block)

(T-2 F43). U.S. Nuclear Regulatory Comm~ s ion, Washngton, DC 20555-0001, or by e-mai I!!

n ta lnlocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and

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(See NUREG-1022, R.3 for instruction and guidance for completing this form Regulatory Affairs, NEOB-10202, (3150-0104). Office of Management and Budget.

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Washngton. DC 20503. II a means used ta inl>ose an nlonnatioo colection does not

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httg:llwww.nrc.gov/reading-rmldoc-collections/nuregs/staft/sr1022/r30 display a currently valid OMB coolrol nurroer, the NRC may not oanducl or sponsor, and a persoo ~not required to respond to, the nfonnatoo coUection

3. Page Peach Bottom Atomic Power Station Unit 2 05000277 1

OF 4

4. Title Emergency Diesel Generator Air Inlet Check Valve Failure Results in a Condition Prohibited by Technical Specifications

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 Peach Bottom Atomic Power Sta. Unit 3 05000278 Facility Name Docket Number 06 13 2018 2018 - 002 0

08 10 2018 05000

9. Operating Mode

11. This Report is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply) 0 20.2201{b) 0 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) 1 D 20.2203(a)(1 i D

D so.73(a)(2)(iii)

D 20.2203(a)(4) 50.73(a)(2)(ix)(A) 0 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 73.71(a)(4) 0 20.2203(a)(2)(iii)

D 50.36(c)(2)

D 50.73(a)(2)(v)(B)

D 73.71 (a)(S)

D 20.2203(a)(2)(iv)

D 50.46(a)(3)(ii)

D 50.73(a)(2)(v)(C)

D 73.77(a)(1>

100%

D 20.2203(a)(2)(v)

D 50.73(a)(2)(i)(A)

D 50.73(a)(2)(v)(D)

D 13.n(a)(2)(i)

D 20.2203(a)(2)(vi)

[8] 50.73(a)(2)(i)(B)

D 50.73(a)(2)(vii)

D 13.77(a)(2)(ii)

D 50.73(a)(2)(i)(C)

D Other (Specify in Abstract below or in SEQUENTIAL NUMBER 002 E-3 EOG. The air inlet check valves for the three remaining EOGs were inspected with no concerns identified. All three EOGs remained operable while E-3 was being repaired.

REV NO.

0 Repairs were completed, post-mqintenance testing performed and the E-3 EOG was declared operable at 7: 1 O pm on 6/23/18. As a result of this event, the E-3 EOG was inoperable for repairs for approximately 9 days, 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />. The previous surveillance test was performed on 5/20/18, 24 days prior to the failed surveillance on 6/13/18. Analysis determined the E-3 EOG would have performed its design function at the time of the May surveillance test, but potentially not afterward. As a result, the E-3 EOG is considered to have been inoperable for a total of approximately 34 days. This exceeds the TS 3.8.1 allowed outage time of 14 days. As a result, this event is being reported in accordance with 1 OCFR 50.73(a)(2)(i)(B), for any operation or condition prohibited by Technical Specifications.

There were no actual safety consequences as a result of this event. The plant's safety analysis assumes one EOG is unavailable. If a design basis event had occurred during the time the E-3 EOG was inoperable, the units could have been safely shutdown with the three remaining EOGs.

Cause of the Event

The cause was determined to be less than adequate repairs to the air inlet check valve during maintenance performed in April of 2017. Several causal factors existed, including shaft bushing wear and inadequate shaft to disk fit, which resulted in higher vibration of the shaft and disk. With the higher vibration, tolerances for the interference fit of the pin to the disk shaft were not adequate to prevent the pin from becoming dislodged.

Corrective Actions

The valve disk, shaft and bushings were replaced and repairs to the EOG were performed as described above. Additional causal factors and corrective actions are documented in the corrective action program.

Previous Similar Occurrences No previous similar occurrences have been identified.

NAC FORM 366A (04-2018)

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