05000387/LER-2018-003, Main Steam Isolation Valve Leakage Due to Pilot Poppet and Pilot Poppet Seat Wear/Degradation
| ML18151B009 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 05/31/2018 |
| From: | Berryman B Susquehanna |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PLA-7714 LER 2018-003-00 | |
| Download: ML18151B009 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3872018003R00 - NRC Website | |
text
HAY 3 1 20t8 Brad Berryman Site Vice President U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Susquehanna Nuclear, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.2904 Fax 570.542.1504 Brad.Berryman@TalenEnergy.com SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-387/2018-003-00 UNIT 1 LICENSE NO. NPF-14 PLA-7714 TALEN~
ENERGY 10 CFR 50.73 Docket No. 50-387 Attached is Licensee Event Report (LER) 50-387/2018-003-00. This LER is reporting an event involving in operability of a Main Steam Line Isolation Valve (MSIV) that was determined to be reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.
There were no actual consequences to the health and safety of the public as a result of this event.
This letter contains no new regulatory commitments.
Should you have any questions regarding this submittal, please contact Mr. Jas ennings, Manager-Nuclear Regulatory Affairs at (570) 542-3155.
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'? VA.\\- fV'l 'a r B. Berryman Attachment: LER 50-387/2018-003-00 Copy:
NRC Region I Ms. T. E. Hood, NRC Project Manager Ms. L. H. Micewski, NRC Sr. Resident Inspector Mr. M. Shields, PA DEP/BRP
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2018)
, the NRC may not conduct or spcnsor, and a person is not required to respond to, the information collection.
- 13. Page Susquehanna Steam Electric Station Unit 1 05000387 1 OF3
- 4. Title Main Steam Isolation Valve Leakage Due to Pilot Poppet and Pilot Poppet Seat Wear/Degradation
- 5. Event Date
- 6. LER Number
- 7. Report Date
- 8. Other Facilities Involved Sequential Rev Facility Name Docket Number Month Day Year Year Month Day Year Number No.
05000 04 05 2018 2018
- - 003
- - 00 OS 31 2011s Facility Name Docket Number 05000
- 9. Operating Mode 08 03 2018 Abstract (Limit to 1400 spaces, i.e., approximately 14 single-spaced typewritten lines)
During Local Leak Rate Testing (LLRT) conducted during the recent Unit 1 refueling outage, combined as-found leakage through the inboard Main Steam Isolation Valve (MSIV) (HV141 F022D) and outboard MSIV (HV141F028D) in the "D" Main Steam Line was 78,782 standard cubic centimeters per minute (seem).
Subsequent testing on April5, 2018, measured the leakage through HV141F028D as 54,623 seem, which exceeded the Technical Specification (TS) 3.6.1.3 limit of 100 scfh (47, 194 seem) for individual valve leakage.
Based on cause and history, there is firm evidence that the condition existed during the last operating cycle for longer than allowed by TS 3.6.1.3. The condition is being reported in accordance with 10 CFR 50. 73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.
The cause of the leakage was identified as pilot poppet and pilot poppet seat wear/degradation. Repairs to the valve were made resulting in an acceptable as-left LLRT.
There were no actual safety consequences associated with the condition.
NRC FORM 366 (04-2018)
CONDITIONS PRIOR TO EVENT
Unit 1 - Mode 5, 0 percent Rated Thermal Power Unit 2 - Mode 1, approximately 1 00 percent Rated Thermal Power YEAR 2018 SEQUENTIAL NUMBER
- - 003 There were no structures, systems, or components that were inoperable at the start of the event that contributed to the event.
EVENT DESCRIPTION
REV NO.
- - 00 During Local Leak Rate Testing (LLRT) conducted during the recent Unit 1 refueling outage, combined as found leakage through the inboard Main Steam Isolation Valve (MSIV) (HV141F022D) [EllS System I Component Code: SB/ISV] and outboard MSIV (HV141 F028D) [EllS System I Component Code: SB/ISV] in the "D" Main Steam Line was 78,782 standard cubic centimeters per minute (seem). Subsequent testing on April 5, 2018, measured the leakage through HV141 F028D as 54,623 seem, which exceeded the Technical Specification (TS) 3.6.1.3 limit of 100 standard cubic feet per hour (scfh) (47, 194 seem) for individual valve leakage.
Based on the test results, HV141 F028D internal inspection and repair was performed. As-found inspection identified guide rib degradation, pilot poppet seating surface degradation, and minor in-body seat indications. As-found valve internal mapping data measured a relatively flat in-body seating surface, with a 0.001" high spot at the 270° seat location. As-found blue check of the pilot poppet seating surface identified seat distortion (i.e. wide and uneven contact line). Pilot poppet and pilot poppet seat degradation were determined to be the main source of as-found leakage.
Based on discussions and evaluation with the original equipment manufacturer (OEM), a repair plan was developed that included lapping of the in-body seat, lapping of the pilot poppet and seating surface, skim cut of the main poppet hard face surface, and clean-up of the identified guide rib degradation.
Based on cause and history, there is firm evidence that the condition existed during the last operating cycle for longer than allowed by TS 3.6.1.3. The condition is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.
CAUSE OF EVENT
The cause was identified as pilot poppet and pilot poppet seat wear/degradation.
ANALYSIS/SAFETY SIGNIFICANCE
Safety significance information will be provided in a supplement to this LER.
NRC FORM 3668 (04-2018)
Page 2 of 3 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2018)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET (See NUREG-1 022, R.3 for instruction and guidance for completing this form http://www. nrc. gov/read i ng-rm/doc-collections/n u regs/staff/sr1 022/r3D
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. LER NUMBER Susquehanna Steam Electric Station Unit 1 05000-387
CORRECTIVE ACTIONS
Corrective actions include the following:
- 1. Repairs to the valve resulting in an acceptable as-left LLRT.
COMPONENT FAILURE INFORMATION
Component Identification - HV141 F028D Component Name - Unit 1 Main Steam Line 'D' 08 Isolation Valve Valve Manufacturer-Atwood & Morrill Valve Type - Wye Globe Valve Size - 26 inch Actuator Manufacturer-Hanna Actuator Type-Tandem Cylinder
PREVIOUS SIMILAR EVENTS
The following are the most recent Susquehanna LERs involving MSIV leakage:
YEAR 2018 SEQUENTIAL NUMBER
- - 003 LER 50-387/2012-006-01, "D" Outboard Main Steam Isolation Valve Leakage-2012, dated August 8, 2013 LER 50-387/2010-004-00, "D" Outboard Main Steam Isolation Valve Leakage-2010, dated August 8, 2013 NRC FORM 3668 (04-2018)
Page 3 of 3 REV NO.
- - 00