05000440/LER-2019-001, Loss of Generator Excitation Causes Turbine Trip and Reactor Protection System Actuation
| ML19114A443 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 04/24/2019 |
| From: | Hamilton D FirstEnergy Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-19-108 LER 2019-001-00 | |
| Download: ML19114A443 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4402019001R00 - NRC Website | |
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FENOC TM
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FirstEnergy Nuclear Operating Company David B. Hamilton Vice President April 24, 2019 L-19-108 ATIN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
Perry Nuclear Power Plant Docket No. 50-440, License No. NPF-58 Licensee Event Report Submittal Perry Nuclear Power Plant PO Box 97 10 Center Road Perry. Ohio 44081 440-280-5382 1 OCFR50.73(a)(2)(iv)(A)
Enclosed is Licensee Event Report (LER) 2019-001, "LER 2019-001, Loss of Generator Excitation causes Turbine Trip and Reactor Protection System Actuation". There are no regulatory commitments contained in this submittal.
If there are any questions or if additional information is required, please contact Mr. Glendon Burnham, Manager - Regulatory Compliance, at (440) 280-7538.
Sincerely, I
David B. Hamilton Vice President
Enclosure:
LER 2019-001 cc:
NRC Project Manager NRC Resident Inspector NRC Region Ill Regional Administrator
Enclosure L-19-108 LER 2019-001
NRC FORM 366 u.s.' NUCLEAR REGULA TORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 3/31/2020 (04-2018)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
3.Page Perry Nuclear Power Plant 05000-440 1 OF 3
- 4. Title:
Loss of Generator Excitation causes Turbine Trip and Reactor Protection System Actuation
- 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 05000 Facility Name Docket Number 02 25 2019 2019 -
001 00 04 24 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) 1 D 20.2201(d)
D 20.2203(a)(3)(ii)
D 50. 73(a)(2)(ii)(B)
D 50. 73(a)(2)(viii)(B)
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)
[gl 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) 74 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
CAUSE OF EVENT
05000-440 YEAR 2019 SEQUENTIAL NUMBER 001 REV NO.
00 The direct cause of the generator lockout, and subsequently the turbine trip followed by an RPS actuation, was a flashover of the exciter brush rigging and carbon brushes which resulted in the loss of the main generator field.
The apparent cause of the event was determined to be inadequate preventive maintenance (PM) acceptance criteria for brush replacement. The criteria for exciter brush inspection and replacement should have added margin to ensure that the brushes could not wear to the point where brush spring tension could no longer be properly maintained.
EVENT ANALYSIS
A Probabilistic Risk Assessment (PRA) evaluation was performed for the automatic RPS actuation. A conservative analysis of this uncomplicated plant transient results in a delta Core Damage Frequency that is well below the acceptable threshold of 1x10-6/year as discussed in Regulatory Guide 1.17 4. The risk of this event is therefore considered very small in accordance with the regulatory guidance. This event was reported in accordance with 10 CFR 50. 73(a)(2)(iv)(A) as an event or condition that resulted in an automatic actuation of the RPS.
CORRECTIVE ACTIONS
A preventative maintenance (PM) revision was performed to modify the brush replacement criteria to add margin to replace brushes earlier in their lifetime, and to ensure that all brushes are checked for vibration during the PM. These actions were completed by 4/2/2019.
Previous Similar Events
A review of LERs and the corrective action database for the past three years identified no similar events.
COMMITMENTS
There are no regulatory commitments contained in this report. Actions described in this document represent intended or planned actions, are described for the NRC's information, and are not regulatory
commitments