05000387/LER-2019-002-01, 1 for Susquehanna Steam Electric Station, Unit 1, Lnoperability of C Emergency Service Water Pump
| ML19352E175 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 12/18/2019 |
| From: | Cimorelli K Susquehanna, Talen Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PLA-7835 LER 2019-002-001 | |
| Download: ML19352E175 (4) | |
| 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 |
| 3872019002R01 - NRC Website | |
text
DEC 1 8 2019 Kevin Cimorelli 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. 570.542.3795 Fax 570.542.1504 Kevin.Cimorelli@TalenEnergy.com SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-387(388)/2019-002-01 UNIT 1 LICENSE NO. NPF-14 UNIT 2 LICENSE NO. NPF-22 PLA-7835 TALEN~,
ENERGY 10 CFR 50.73 Docket No. 50-387 and 50-388 Attached is a supplement to Licensee Event Report (LER) 50-387(388)/2019-002-00 that reported an event involving the "C" Emergency Service Water pump that was determined to be reportable 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) as an event or condition that could have prevented fulfillment of a safety function.
There were no actual consequences to the health and safety of the public as a result of this event.
Attachment: LER 50-387(388)/2019-002-01 Copy:
NRC Region I Ms. S. Goetz, NRC Project Manager Ms. L. H. Micewski, NRC Sr. Resident Inspector Mr. M. Shields, PA DEP/BRP
NRC FORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2018)
, the NRC may not conduct or sponsor, and a oerson is not reauired to resoond to the information collection.
- 13. Page Susquehanna Steam Electric Station Unit 1 05000387 1 OF3
- 4. Title lnoperability of "C" Emergency Service Water Pump
- 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 Susquehanna Steam Electric Station Unit 2 Number No.
05000388 08 28 2019 2019 002 01 12 18 2019 Facility Name Docket Number N/A 05000
- 9. Operating Mode Abstract (Limit to 1400 spaces, i.e., approximately 14 single-spaced typewritten lines)
On August 28, 2019 at approximately 17:40, during lnservice Testing (1ST) of the "A" loop of Emergency Service Water (ESW), the differential pressure for the "C" ESW pump (OP504C) was found to be 88.875 psid, which was below the established 1ST acceptance criteria. Based on the test results, the "C" ESW pump was in the 1ST Required Action Range, which requires the pump to be declared inoperable. At the time of discovery of this condition, Susquehanna was already in Technical Specification (TS) 3.7.2 Condition C for "A" loop maintenance. On August 29, 2019, the pump lift setting was adjusted and the "C" ESW pump was retested. The retest resulted in an acceptable differential pressure of 91.9 psid, which was in the Alert Range and no longer in the Required Action Range.
TS 3.7.2 Condition C was exited on August 29, 2019 at approximately 15:45. On October 04, 2019, Susquehanna completed replacement of the "C" ESW pump.
The direct cause was determined to be separation of the lower pump casing flange (bottom column to top case) resulting in a loss of differential pressure. The apparent cause was determined to be corrosion of the carbon steel bolting in raw water. This was accelerated by galvanic interactions with silt, Copper never-seize, and alloy steel. Completed corrective actions include replacement of the "C" ESW pump. Planned corrective actions include a review of the appropriate preventive maintenance (PM) frequency for pump replacement.
Based on available information, the condition is considered to have existed for longer than allowed by TS 3.7.2. 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) as an event or condition that could have prevented fulfillment of a safety function.
There were no actual safety consequences associated with the condition.
NRC FORM 366 (04-2018)
CONDITIONS PRIOR TO EVENT
Unit 1 - Mode 1, approximately 100 percent Rated Thermal Power Unit 2 - Mode 1, approximately 100 percent Rated Thermal Power YEAR 2019 SEQUENTIAL NUMBER 002 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.
01 1
On August 28, 2019 at approximately 17:40, during lnservice Testing (1ST) of the "A" loop of Emergency Service Water (ESW) [EllS System Code: Bl], the differential pressure for the "C" ESW pump (OP504C)
[EllS Component Code: P] was found to be 88.875 psid, which was below the established 1ST acceptance criteria. Based on the test results, the "C" ESW pump was in the 1ST Required Action Range, which requires the pump to be declared inoperable. At the time of discovery of this condition, Susquehanna was already in Technical Specification (TS) 3.7.2 Condition C for both units in support of maintenance activities on the "A" loop of ESW.
On August 29, 2019, the pump lift setting was adjusted and the "C" ESW pump was retested. The retest resulted in an acceptable differential pressure of 91.9 psid, which was in the Alert Range and no longer in the Required Action Range. TS 3.7.2 Condition C was exited on August 29, 2019 at approximately 15:45.
On October 04, 2019, Susquehanna completed replacement of the "C" ESW pump. The removed pump had notable degradation, including flange separation and bolting corrosion. The pump had been installed for slightly more than 10 years prior to replacement. Other pumps exposed to the same raw water environment include the "A", "B", and "D" ESW pumps and the "1A", "1 B", "2A", and "2B" Residual Heat Removal Service Water (RHRSW) pumps [EllS System/Component Code: BI/P]. Of these pumps, the "2B" RHRSW has been installed for the longest period of time (slightly more than 11 years).
Based on available information, the condition is considered to have existed for longer than allowed by TS 3.7.2. The condition is therefore being reported in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications. The "B" loop of ESW was determined to have been out of service and inoperable for ten minutes for system valve testing on September 29, 2019; as a result, the condition is also being reported in accordance with 10 CFR 50. 73(a)(2)(v) as an event or condition that could have prevented fulfillment of a safety function.
CAUSE OF EVENT
The direct cause was determined to be separation of the lower pump casing flange (bottom column to top case) resulting in the flange o-ring protruding and subsequent loss of differential pressure. The apparent cause was determined to be corrosion of the carbon steel bolting in raw water. This was accelerated by galvanic interactions with silt, Copper never-seize, and alloy steel. Page 2 of 3 U.S. NUCLEAR REGULATORY COMMISSION (04-2018)
&*~Jttdv<._.
/¥'
>>*~,.~
LICENSEE EVENT REPORT (LER)
~
"JI.
\\, o.r/
CONTINUATION SHEET
- -tU""
(See NUREG-1 022, R.3 for instruction and guidance for completing this form http://wwvv.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1 022/r3D APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. LER NUMBER YEAR Susquehanna Steam Electric Station Unit 1 05000-387 2019
ANALYSIS/SAFETY SIGNIFICANCE
SEQUENTIAL NUMBER 002 REV NO.
01 1
An engineering evaluation was completed to analyze having only the 'A' ESW pump available. The engineering evaluation concluded that, with only the 'A' ESW pump in operation, all ESW users could have removed the required heat load and all safety related ESW users would have performed their safety related functions. Based on the Engineering evaluation, the condition involving the 'C' ESW pump not being able to perform its safety function did not result in a safety system functional failure. Accordingly, this event will not be counted as a safety system functional failure in the Reactor Oversight Process Performance Indicators.
[CORRECTIVE ACTIONS Key corrective actions include the following:
- 1. Susquehanna completed replacement of the "C" ESW pump on October 04, 2019.
- 2. Susquehanna will determine the appropriate preventive maintenance frequency for pump replacement.
In addition to the actions above, an extent of condition action will be taken to inspect the 2P506B RHRSW Pump to determine if similar corrosion is observed.
COMPONENT FAILURE INFORMATION
Component Identification-OP504C Component Name-Emergency Service Water Pump Pump Manufacturer-Flowserve Corporation (previously Byron Jackson Pump Company)
Pump Type -One-Stage Vertical Circulator Pump Mode1No.-24BXF1-STG.VCT
PREVIOUS OCCURENCES
No significant previous occurrences were identified.! Page 3 of 3