05000277/LER-2018-002-01, Emergency Diesel Generator Air Inlet Check Valve Failure Results in a Condition Prohibited by Technical Specifications
| ML19064B342 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  (DPR-044, DPR-056) |
| Issue date: | 03/04/2019 |
| From: | Pat Navin Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CCN: 19-25 LER 2018-002-01 | |
| Download: ML19064B342 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(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)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2772018002R01 - NRC Website | |
text
Exelon Generation CCN: 19-25 March 4, 2019 U. S. Nuclear Regulatory Commission ATTN: 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 NRG Docket No. 50-277 and 50-278
Subject:
Licensee Event Report (LEA) 2-18-002, Revision O 1 Enclosed is Revision 1 to a Licensee Event Report concerning a violation of Technical Specifications caused by a failure of an Emergency Diesel Generator. The revision was made to adjust the total number of days the diesel generator was considered to be inoperable.
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 LEA. If you have any questions or require additional information, please do not hesitate to contact Matthew Retzer at 717-456-3351.
Sin7b-3 Patrick D. Navin Site Vice President Peach Bottom Atomic Power Station PDN/dnd/IR 4146926 Enclosure cc:
US NRG, Administrator, Region I US NRG, Senior Resident Inspector R. R. Janati, Commonwealth of Pennsylvania D. Tancabel, 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: 03/3112020 (04-2018)
Estinated burden per response to comp~ with this mandatory collectlln request* BO hours
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LICENSEE EVENT REPORT (LER)
Reported lessons learned are ncorporated i1to the licensing process and fed back to industry. Send comments regard'ng burden estmate to the lnlormation 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 Commission. Washington, DC 20555-0001, or by e-maH I!!
to lnfocollects.Resource@nrc.gov, and to the Desk Officer. Otti:e of lnfonmatK:>n and 0
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(See NUREG-1022, R.3 for instruction and guidance for completing this form Regulatory Affairs, NEOB-10202, (3150-0104), Office ol Management and Budget,
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person ~not required to respond to, the ilfonmation collection.
- 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 01 03 04 2019 05000
- 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)(8)
D 50. 73(a)(2)(viii)(B) 1 D
D D
D 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(iii) 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 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) 100%
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)
[8J 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 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.
01 Repairs were completed, post-maintenance 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 may not have been able to perform its design function for the seven day mission time since April 2017, prior to the preventive maintenance activities that replaced the pin. As a result, the E-3 EOG is considered to have been inoperable for a total of approximately 443 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. Page_3_ of~