ML25132A118
| ML25132A118 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 05/22/2025 |
| From: | Nebraska Public Power District (NPPD) |
| To: | Byrd T Office of Nuclear Reactor Regulation |
| Wengert T, NRR/DORL/LPLIV, 415-4037 | |
| References | |
| EPID L-2025-LRM-0053 | |
| Download: ML25132A118 (16) | |
Text
Pre-Submittal Meeting: RE34 Diesel Generator Fuel Oil Storage Tank Cleaning/Inspection May 22, 2025
Agenda
Introductions
Maintenance Requirements Technical Specification (TS) Requirements
System Design
System Drawing Purpose of Request Conduct of Maintenance Permanent Equipment Lineup Use of Temporary Equipment Considerations TS Revision to Limiting Condition of Operation (LCO) 3.8.3 Precedents Submittal Timeline
Maintenance Requirements CNS License Renewal Buried Pipe and Tanks Inspection Program (NLS2010050-04, ADAMS Accession Number ML101310605) and Diesel Fuel Monitoring Program (NLS2008071-06, ADAMS Accession Number ML083030225) require periodic emptying, cleaning and examination of the buried Diesel Fuel Oil Storage Tanks CNS Engineering Evaluation (EE)11-037 established a 20-year re-inspection interval recommended by vendor tank thickness and corrosion rate evaluations in 2004.
CNS was scheduled to perform the work in the Fall of 2024.
Difficulties with a vendor prevented the work from being completed.
Inspection was last completed in 2004
Technical Specification Requirements
- This request will be performed during Refuel Outage 34 (October 2026) while in Mode 5
System Design
- Two Diesel Generators (DG)
- Two Diesel Generator Fuel Oil (DGFO) Storage Tanks
- Two DGFO Transfer Pumps; One located in each tank
- DGs and Transfer Pumps are divisional
- Both DGFO Storage Tanks required to meet 7 day supply of fuel oil for one DG.
- DGDO fuel supply system is cross connected so that total capacity of both tanks can be directed to either DG
System Drawing
Purpose of Request
- Purpose of license amendment request is to take credit for the fuel oil volume stored in temporary tank(s) in meeting the Technical Specifications requirement of a 7-day supply of fuel oil.
Conduct of Maintenance
- Both fuel oil storage tanks will be tagged and drained to facilitate cleaning, inspection and, if needed, repair.
- Transfer pumps for tanks will be deenergized and isolated from system
- An alternate fuel oil storage system will be used to drain the fuel oil storage tanks and store the 7-day supply of fuel oil.
- The alternate fuel oil storage system will be capable of providing the 7-days of fuel oil to the DG day tanks.
Permanent Equipment Lineup
- Buried storage tanks will be drained of all fuel oil
- DG day tank volume will be maintained per Tech Specs
- Maintenance will be performed on opposite DG
Use of Temporary Equipment
- Minimum 50,000 gallons (7-day supply) of diesel fuel will be available in the temporary storage tanks
- Contents of buried tanks will be off-loaded using filtration equipment to the temporary storage tanks
- Temporary pump/filter equipment, independent of electrical power sources, will be pre-staged to transfer off-loaded fuel to the required DG day tank
- Special Procedures will be approved with instructions to transfer fuel oil from the temporary storage tanks to the required DG day tank in the event of a loss offsite power.
- Potential use of alternate fuel oil storage system to fill opposite DG day tank.
Considerations
- Seismic
- Temporary equipment will be at site grade level (elevation 903 ft Mean Sea Level)
- Location is Type I Fill, or Structural Fill, consisting of highly compacted backfill down to site bedrock
- Security
- Temporary equipment will be located inside CNS Protected Area
- Security impacts evaluated using CNS Procedure 0-SEC-INTERFACE
- Temporary equipment impacts on FLEX travel paths and staging areas has been evaluated with no impacts noted.
Technical Specification Revision to LCO 3.8.3 (Sample)
TEMPORARY NOTE During Refuel Outage 34, the diesel fuel oil storage tanks (FOSTs) may be made inoperable and drained to support cleaning, inspection, testing, and associated repair activities without entering Conditions A and F, provided the following are satisfied.
a.
Verify once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> that the Alternate Fuel Oil Supply System contains at least a 7-day supply of fuel oil.
b.
While in standby, verify once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> that the required diesel generator day tank provides at least a 3.9-hour supply of fuel oil.
c.
The compensatory measures specified in Attachment 2 to Nebraska Public Power District letter NLS2025026 are met.
d.
FOSTs must be restored within 14 days.
If Notes 2.a through 2.d are not satisfied, then enter Condition F.
SR 3.8.1.6 and SR 3.8.3.1 are not required to be met during the FOSTs inspection evolution.
Note 2 expires upon completion of the FOSTs inspection evolution during Refuel Outage 34.
Precedents Monticello Nuclear Generating Plant, Revise Technical Specifications to Support a Ten-Year Inspection of the Diesel Generator Fuel Oil Storage Tank, Amendment 209 Safety Evaluation dated December 27, 2022 (ADAMS Accession Number ML22318A215)
Cooper Nuclear Station, Revision to Technical Specifications 3.8.3, Diesel Fuel Oil, Lube Oil, and Starting Air, to Allow for Cleaning, Inspection and Any Needed Repairs During Refuel Outage 33.
Amendment 276 Safety Evaluation dated July 3, 2024 (ADAMS Accession Number ML24134A178)
Precedents Both precedents use temporary storage tanks to meet the TS required inventory Using similar temporary storage and transfer system as approved in Amendment 276 for CNS Differences from previous CNS evolution:
- Instead of allowing the evolution to be performed in Modes 4 and 5, will be required to be in Mode 5, with cavity flooded and fuel pool gates removed
- Cleaning and inspecting both storage tanks at same time, which involves off-loading all stored fuel to temporary tanks similar to Monticellos maintenance evolution
- For LOOP, fuel oil will be pumped directly from temporary storage tanks directly to the required DG day tank
- This evolution requires opening a vital area door for the DG room
Submittal Timeline
- Submit to NRC July 2025
- Estimated 1-yr NRC review time
- Implement within 60 days of NRC approval
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