ML25289A350
| ML25289A350 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 10/16/2025 |
| From: | Knowles J Rochester Gas & Electric Corp |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| EPID L-2025-LLA-0087 | |
| Download: ML25289A350 (1) | |
Text
200 Energy Way Kennett Square, PA 19348 www.constellationenergy.com 10 CFR 50.90 October 16, 2025 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 R.E. Ginna Nuclear Power Plant Renewed Facility Operating License No. DPR-18 NRC Docket No. 50-244
Subject:
Supplemental Information to Support Review of a License Amendment Request to Extend the Completion Time for Sodium Hydroxide System
References:
- 1.
Letter from J. Knowles (Constellation Energy Generation, LLC (CEG)) to the U.S.
Nuclear Regulatory Commission, R. E. Ginna Nuclear Power Plant - License Amendment Request to Extend the Completion Time for Sodium Hydroxide System, Dated May 20, 2025 (ADAMS Accession No ML25140A128) (EPID L-2025-LLA-0087)
- 2.
Letter from V. Sreenivas (U.S. NRC) to D. Rhoades (Constellation Energy Generation, LLC (CEG)), R. E. Ginna Nuclear Power Plant - Audit Plan in Support of License Amendment Request to Extend the Completion Time for Sodium Hydroxide System, Dated August 28, 2025 (ADAMS Accession No ML25233A245) (EPID L-2025-LLA-0087)
By letter dated May 20, 2025 (Reference 1) Constellation Energy Generation, LLC (CEG) requested an amendment to Renewed Facility Operating License No. DPR-18 for R.E. Ginna Nuclear Power Plant (Ginna). The proposed change was to extend the Completion Time for Technical Specification (TS) 3.6.6 Containment Spray (CS), Containment Recirculation Fan Cooler (CRFC), and NaOH Systems, Required Action B Sodium Hydroxide (NaOH) system inoperable. Specifically, the proposed change extends the Required Action B Completion Time from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days.
By letter dated August 28, 2025 (Reference 2) the NRC outlined the plan to conduct a regulatory audit between September 8 and September 30, 2025 to examine CEG non-docketed information to support the basis of the licensing decision.
Following discussion during the regulatory audit, CEG is revising the original request made in the letter dated May 20, 2025 (Reference 1). CEG is now requesting to extend the Completion Time for Sodium Hydroxide System from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days. contains the supplemental information to support the basis of the licensing decision for License Amendment Request to Extend the Completion Time for Sodium Hydroxide System. Attachment 2 contains the markup of Ginna TS reflecting the 7 day requested completion time. Attachment 3 contains the markup of Ginna Technical Specification Bases for information only.
The proposed changes have been reviewed by the Ginna Plant Operations Review Committee in accordance with the requirements of the CEG Quality Assurance Plan.
This letter contains no new regulatory commitments.
Should you have any questions concerning this letter, please contact Michael Henry at 267-533-5382.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 16th day of October 2025.
Respectfully, Justin Knowles Senior Manager - Licensing Constellation Energy Generation, LLC Attachments:
- 1. Supplemental Information for NaOH System Completion Time Extension
- 2. Markup of Technical Specifications Pages for Technical Specification 3.6.6
- 3. Markup of Technical Specifications Bases Pages for Technical Specification 3.6.6 cc:
NRC Regional Administrator, Region I NRC Senior Resident Inspector, Ginna NRC Project Manager, Ginna
Bcc w/ attachments:
Corporate Executive Distribution Ginna Sr. Leadership Team Distribution Corporate Licensing East Distribution Ginna RAM (Justin Follett)
Ginna Reg. Assurance Engineer (Claire Schmittinger)
Ginna Manager Engineering (Joshua Camp)
Ginna Engineer (Damon Peters)
Fuels Engineer (Christopher Staum)
ATTACHMENT 1 Supplemental Information for NaOH System Completion Time Extension R.E. Ginna Nuclear Power Plant NRC Docket No. 50-244
SUMMARY
DESCRIPTION By letter dated May 20, 2025 (ADAMS Accession no ML25140A128) Constellation Energy Generation, LLC (CEG) submitted a License Amendment Request (LAR) to Appendix A, Technical Specifications (TS) of Renewed Facility Operating License DPR-18 for R.E. Ginna Nuclear Power Plant (Ginna). The proposed change was to extend the Completion Time for TS 3.6.6 Containment Spray (CS), Containment Recirculation Fan Cooler (CRFC), and NaOH Systems Condition B NaOH system inoperable from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days.
A regulatory audit was conducted by the NRC as outlined in letter dated August 28, 2025 (ADAMS Accession no ML25233A245). Following the regulatory audit CEG is now requesting an extension to the Completion Time for TS 3.6.6 Containment Spray (CS), Containment Recirculation Fan Cooler (CRFC), and NaOH Systems Condition B NaOH system inoperable from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days. During the regulatory audit, it became apparent that the projected time to restore the NaOH System following failures could be completed in a 7-day period.
SYSTEM MAINTENANCE DESCRIPTION The NRC requested CEG to provide an evaluation of failure mechanisms of the NaOH system and discuss possible separate conditions and appropriate completion times for each type of failure.
Several failure mechanisms were considered, with a failure of the NaOH Spray Additive Tank having the most limiting time to restore the system to operable.
The NaOH System consists of one 5100-gallon Spray Additive Tank where the 30 to 35 weight percent sodium hydroxide solution is stored with an inert nitrogen blanket.
Two failure mechanisms are considered for the Spray Additive Tank. The first failure mechanism considered is the NaOH solution concentration being out of specification.
A review of the history of the NaOH Spray Additive Tank indicated that routine sampling results for NaOH concentration lowered because of leakage past the valves interacting with the Refueling Water Storage Tank (RWST). The change in concentration required the contents of the tank to be partially drained and replenished. This concentration adjustment was completed in the 2020 refueling outage to mitigate the potential plant shutdown due to the duration of the evolution. Adjusting the NaOH Spray Additive Tank concentration involves setting up portable totes, a temporary pump, and hoses; isolating the work area and depressurizing the tank; configuring the air system to drain the tank; draining to the required level for adding properly concentrated NaOH; recirculating for thorough mixing; sampling and analysis; and finally, removing temporary equipment and restoring the work area. This evolution is further complicated by a congested work area requiring additional support activities such as fire watch tours and opening of a fire barrier penetration.
ATTACHMENT 1 Page 2 Supplemental Information for NaOH System Completion Time Extension NRC Docket No. 50-244 The concern with out of specification NaOH concentration would be further complicated if the results of routine sampling for Surveillance Requirement 3.6.6.8 were found to be out of specification unexpectedly, requiring action to be taken while the plant is in operation.
Temporary setup of equipment would be required to start at the time of discovery rather than at a pre-planned time. Additionally, a larger volume of NaOH would be required to bring the concentration back into specification. Large volumes of NaOH are not maintained on site due to the low need for use. The NaOH Spray Additive Tank concentration adjustment performed in the 2020 refueling outage was preplanned and the evolution took greater than 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br />. If the NaOH Spray Additive Tank concentration is unexpectedly found out of specification and chemicals must be ordered, the current 72-hour completion time will likely be exceeded. If a substantial concentration adjustment is necessary and the initial attempt does not achieve the desired result, a second 14-hour recirculation of the NaOH Spray Additive Tank to ensure thorough mixing would be required. This process would extend the total duration to approximately 85 to 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br />.
The second NaOH Spray Additive Tank failure mechanism considered is gross leakage from the spray additive tank at an inconvenient location like the weld seam at the bottom of the tank.
Much of the maintenance for a weld repair would be the same as the previously discussed NaOH concentration adjustment. Gross leakage from the NaOH Spray Additive Tank will also require additional cleanup efforts to allow maintenance to work in a suitable environment. A weld repair to the Spray Additive Tank and the subsequent quality control inspections will take approximately 12 to 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> to complete. This failure mechanism is expected to take 100 to 110 hours0.00127 days <br />0.0306 hours <br />1.818783e-4 weeks <br />4.1855e-5 months <br /> to resolve.
Completion time in TS is the amount of time allowed for completing a required action. TS completion times normally use 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, 7 days, and 14 days. The limiting maintenance, a gross leakage from the weld seam, is projected to take approximately four and half days. A completion time of 7 days is appropriate to use for TS 3.6.6 Condition B because it will allow time to restore the system while maintaining the standard completion times.
EQUIPMENT QUALIFICATIONS Additional information was requested during the regulatory audit to assess the equipment qualification for submerged equipment during an accident if NaOH is not injected.
At Ginna the equipment that is submerged during a Large Break Loss of Coolant Accident (LBLOCA) will also be submerged during smaller break LOCAs where NaOH is not injected.
The limiting sump pool level above the containment basement floor was previously calculated to be 3.55 feet for a LOCA with NaOH injection. For 1.1-inch and 2-inch Small Break Loss of Coolant Accident (SBLOCA), containment spray is not initiated, and the sump pool level was calculated to be above 3.6 feet. In the event of a LOCA with spray initiated a portion of the water in containment will accumulate in the refueling cavity and not in the containment sump whereas in the SBLOCA without containment spray discharging there is no water accumulation in the refueling cavity. Since containment spray was not initiated in the SBLOCA cases, there is no NaOH in the sump pool water. Therefore, the equipment exposed to the sump pool water
ATTACHMENT 1 Page 3 Supplemental Information for NaOH System Completion Time Extension NRC Docket No. 50-244 during an LBLOCA without NaOH available would be the same as the SBLOCAs under 2-inches.
At low sodium hydroxide concentrations, the stress cracking boundary is at a much higher temperature than at higher sodium hydroxide concentrations. Therefore, with no sodium hydroxide available for addition the likelihood of caustic stress cracking is reduced.
The largest source of chlorides for the post-accident containment sump pool is Vinylcel insulation on the inner surface of the containment liner. Vinylcel insulation would release chlorides into the containment post-accident environment in the weeks following a design basis accident. The estimated NaCl concentration with all the chlorides released would be 0.6 percent, which is below the 5 percent where no Chloride stress corrosion cracking failures are expected.
CONTROL ROOM HABITABILITY The NRC requested information regarding the potential for re-evolution of iodine due to an unbuffered containment sump.
The re-evolution of iodine from the containment sump would contribute only incremental quantities of iodine which do not significantly affect the short-term dose exposure. The potential long-term impacts are limited to a 10 to 20 percent increase in iodine-based dose exposure.
With the primary concern of iodine re-evolution being longer term and the only expected Alternative Source Term (AST) LOCA Dose acceptance criteria to be challenged is the exposure to control room operators, there exists sufficient time for the Operators to react and perform additional exposure mitigation techniques such as the use of Self-Contained Breathing Apparatus (SCBA) and potassium iodide (KI) supplements.
CONCLUSION CEG is requesting an extension to the Completion Time for TS 3.6.6 Containment Spray (CS),
Containment Recirculation Fan Cooler (CRFC), and NaOH Systems Condition B NaOH system inoperable from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days. The letter dated May 20, 2025 (ADAMS Accession no ML25140A128) had requested the completion time for TS 3.6.6 Condition B be extended to 14 days, CEG is now requesting a 7 day completion time for TS 3.6.6 Condition B. Changing the proposed completion time from the original 14 days to 7 days does not impact the conclusions of the initial amendment request made in the letter dated May 20, 2025 (ADAMS Accession no ML25140A128). The conclusion of the technical evaluation, No Significant Hazards Consideration, and Environmental Assessment remain unchanged due to the additional information provided in this supplement.
Markup of Technical Specifications Pages for Technical Specification 3.6.6 R.E. Ginna Nuclear Power Plant NRC Docket No. 50-244 REVISED TECHNICAL SPECIFICATIONS PAGE 3.6.6-1
CS, CRFC, and NaOH Systems 3.6.6 3.6 CONTAINMENTSYSTEMS 3.6.6 Containment Spray (CS), Containment Recirculation Fan Cooler (CRFC), and NaOH Systems LCO 3.6.6 Two CS trains, four CRFC units, and the NaOH system shall be OPERABLE.
- NOTE -
In MODE 4, both CS pumps may be in pull-stop for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the performance of interlock and valve testing of motor operated valves (MOVs) 857A, 857B, and 857C. Power may also be restored to MOVs 896A and 896B, and the valves placed in the closed position, for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the purpose of each test.
APPLICABILITY:
MODES 1, 2, 3, and 4.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.
One CS train inoperable.
A.1 Restore CS train to OPERABLE status.
72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> OR
NOTE--------
Not applicable if there is a loss of function.
In accordance with the Risk Informed Completion Time Program B.
NaOH system inoperable.
B.1 Restore NaOH System to OPERABLE status.
72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> C.
Required Action and associated Completion Time of Condition A or B not met.
C.1 Be in MODE 3.
AND C.2 Be in MODE 5.
6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 84 hours R.E. Ginna Nuclear Power Plant 3.6.6-1 Amendment 7 days
Markup of Technical Specification Bases Pages for Technical Specification 3.6.6 R.E. Ginna Nuclear Power Plant NRC Docket No. 50-244 REVISED TECHNICAL SPECIFICATION BASES PAGE B 3.6.6-7
CS, CRFC and NaOH Systems B 3.6.6 B 3.6.6-7 Revision 107 R.E. Ginna Nuclear Power Plant APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment and an increase in containment pressure and temperature requiring the operation of the CS System, CRFC System and NaOH System.
In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Thus, the CS System, CRFC System and NaOH System are not required to be OPERABLE in MODES 5 and 6.
ACTIONS A.1 With one CS train inoperable, the inoperable CS train must be restored to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or in accordance with the Risk Informed Completion Time Program. In this Condition, the remaining OPERABLE spray and CRFC units are adequate to perform the iodine removal and containment cooling functions. The Completion Times take into account the redundant heat and iodine removal capability afforded by the CRFCs, reasonable time for repairs, and low probability of a DBA occurring during this period.
B.1 With the NaOH System inoperable, OPERABLE status must be restored within 7 days72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The pH adjustment of the Containment Spray System flow for corrosion protection and iodine removal enhancement is reduced in this condition. The Containment Spray System would still be available and would remove some iodine from the containment atmosphere in the event of a DBA. The 7 day72 hour completion time takes into account the redundant flow path capabilities and the low probability of the worst case DBA occurring during this period.
C.1 and C.2 If the inoperable CS train or the NaOH System cannot be restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 84 hours9.722222e-4 days <br />0.0233 hours <br />1.388889e-4 weeks <br />3.1962e-5 months <br />. The allowed Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is reasonable, based on operating experience, to reach MODE 3 from full power conditions in an orderly manner and without challenging plant systems. The extended interval to reach MODE 5 allows additional time for attempting restoration of the inoperable component(s) and is reasonable when considering the driving force for a release of radioactive material from the Reactor Coolant System is reduced in MODE 3.