05000387/LER-2018-004, Condition Prohibited by Technical Specifications Resulting from Locked Snubber
| ML18165A461 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 06/14/2018 |
| From: | Berryman B Susquehanna, Talen Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 2018-004-00 | |
| Download: ML18165A461 (3) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3872018004R00 - NRC Website | |
text
JUN 1 4 2018 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 50-387/2018-004-00 UNIT 1 LICENSE NO. NPF-14 PLA-7716 TALEN~,
ENERGY 10 CPR 50.73 Docket No. 50-387 Attached is Licensee Event Report (LER) 50-387/2018-004-00. This LER is repmiing an event involving a locked main steam line snubber that was determined to be reportable in accordance with 10 CPR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications and 10 CPR 50.73(a)(2)(v)(C) as a condition that could have prohibited fulfillment of a safety function.
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. Jason Jennings, Manager-Nuclear Regulatory Affairs at (570) 542-3155.
B. Benyman Attachment: LER 50-387/2018-004-00 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)
Eslimaled, lhe NRC may nol conduct or sponsor, and a person is nol reauired to respond lo lhe informalion colleclion.
- 1. Facility Name
~- Docket Number 3.Page Susquehanna Steam Electric Station Unit 1 05000387 1 OF2
- 4. Title Condition Prohibited by Technical Specifications Resulting from Locked Snubber
- 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 N/A Number No.
05000 04 20 2018 2018
- - 004
- - 00 ot9
\\q 2018 Facility Name Docket Number N/A 05000
- 9. Operating Mode 08 03 2018 Abstract (Limit to 1400 spaces, i.e., approximately 14 single-spaced typewritten lines)
On April20, 2018 during the Unit 1 20th Refuel and Inspection Outage (RIO) scheduled maintenance, Snubber MST22-H38 on the 'D' Main Steam Line (MSL) was found in a locked position. Engineering evaluation of the as-found snubber condition indicates that operability of the 'D' inboard Main Steam Isolation Valve (MSIV) and 'K' Automatic Depressurization System (ADS) Valve and 'K' ADS valve discharge piping were impacted. Based on available information, the condition appears to have existed during the last operating cycle for a period longer than allowed by Technical Specifications. As a result, Technical Specification (TS) 3.6.1.3, Primary Containment Isolation Valves (PCIVs), and TS 3.5.1, Emergency Core Cooling Systems (ECCS)- Operating, were not met.
The condition is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications and 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prohibited fulfillment of a safety function due to a concurrent condition associated with the outboard MSIV on the 'D' MSL. This concurrent condition was previously reported in LER 50-387/2018-003-00 on May 31, 2018.
The cause of this event is still under investigation. Once determined, this information and the associated corrective actions will be communicated through a supplement to this LER.
There were no actual consequences to the health and safety of the public as a result of this event.
NRC FORM 366 (04-2018)
CONDITIONS PRIOR TO EVENT
Unit 1 - Mode 5, 0 percent Rated Thermal Power
EVENT DESCRIPTION
YEAR 2018 SEQUENTIAL NUMBER
- - 004 REV NO.
- - 00 On April 20, 2018 during Unit 1 201h RIO scheduled maintenance, Snubber MST22-H38 on the 'D' Main Steam Line was found in a locked position. The snubber was removed and replaced_ with a rebuilt snubber.
Engineering evaluation of the as-found snubber condition indicates that operability of the 'D' inboard MSIV and 'K' ADS Valve and 'K' ADS valve discharge piping were impacted. Concurrent to this issue, the 'D' outboard MSIV was determined to be inoperable due to excessive leak through as reported in LER 50-387/2018-003-00 on May 31, 2018. Based on available information, the condition appears to have existed during the last operating cycle for a period longer than allowed by TS 3.6.1.3, Condition B due to two PCIVs being inoperable, and TS 3.5.1, Condition F due to one ADS valve being inoperable.
The condition is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications and 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prohibited fulfillment of a safety function.
Additional details related to the event description will be provided under a supplement to this LER.
CAUSE OF EVENT
The cause of this condition is still under investigation. Additional information associated with the cause will be provided in a supplement to this LER.
ANALYSIS/SAFETY SIGNIFICANCE
Information concerning the safety significance of this condition will be provided in a supplement to this LER.
CORRECTIVE ACTIONS
The corrective actions will be determined following completion of the cause analysis and will be provided in a supplement to this LER.
COMPONENT FAILURE INFORMATION
The cause of this condition is still under investigation. Additional information associated with the cause will be provided in a supplement to this LER.
PREVIOUS SIMILAR EVENTS
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