ML26048A478
| ML26048A478 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  (NPF-069) |
| Issue date: | 02/23/2026 |
| From: | Richard Guzman NRC/NRR/DORL/LPL1 |
| To: | Mudrick C Constellation Energy Generation |
| Guzman R, NRR/DORL/LPL1 | |
| References | |
| EPID L-2025-LLA-0110 | |
| Download: ML26048A478 (0) | |
Text
February 23, 2026 Mr. Christopher H. Mudrick Sr.
Senior Vice President Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 200 Exelon Way Kennett Square, PA 19348
SUBJECT:
NINE MILE POINT NUCLEAR STATION, UNIT 2 - ISSUANCE OF AMENDMENT NO. 202, REVISION TO TECHNICAL SPECIFICATIONS REGARDING THE MAIN STEAM LINE AREA TEMPERATURE (EPID L-2025-LLA-0110)
Dear Mr. Mudrick:
The U.S. Nuclear Regulatory Commission (NRC or the Commission) has issued the enclosed Amendment No. 202 to Renewed Facility Operating License No. NPF-69 for the Nine Mile Point Nuclear Station, Unit 2 (Nine Mile Point 2). The amendment consists of changes to the technical specifications (TSs) in response to the application from Constellation Energy Generation, LLC dated July 18, 2025, as supplemented by [[letter::NMP2L2929, Response to Request for Additional Information for License Amendment Request to Revise Technical Specification 3.3.6.1-1 and Add New Technical Specification 3.7.7, Main Steam Line (MSL) Area Temperature|letter dated October 29, 2025]].
The amendment removes Trip Function 1.e, Main Steam Line Tunnel Temperature - High, Trip Function 1.f, Main Steam Line Tunnel Differential Temperature - High, and Trip Function 1.g, Main Steam Line Tunnel Lead Enclosure Temperature - High, from Table 3.3.6.1-1, Primary Containment Isolation Instrumentation, and adds a new TS, Main Steam Line (MSL) Area Temperature, requiring manual action when the MSL area temperature is above the specified temperature limit.
A copy of the related safety evaluation is enclosed. A Notice of Issuance will be included in the Commissions monthly Federal Register notice.
Sincerely,
/RA/
Richard V. Guzman, Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-410
Enclosures:
- 1. Amendment No. 202 to NPF-69
- 2. Safety Evaluation cc: Listserv
NINE MILE POINT NUCLEAR STATION, LLC LONG ISLAND LIGHTING COMPANY CONSTELLATION ENERGY GENERATION, LLC DOCKET NO. 50-410 NINE MILE POINT NUCLEAR STATION, UNIT 2 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 202 Renewed License No. NPF-69
- 1.
The U.S. Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Constellation Energy Generation, LLC dated July 18, 2025, as supplemented by [[letter::NMP2L2929, Response to Request for Additional Information for License Amendment Request to Revise Technical Specification 3.3.6.1-1 and Add New Technical Specification 3.7.7, Main Steam Line (MSL) Area Temperature|letter dated October 29, 2025]], complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the Commissions rules and regulations set forth in 10 CFR Chapter I;
B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.
- 2.
Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Renewed Facility Operating License No. NPF-69 is hereby amended to read as follows:
2.C.(2) Technical Specifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, as revised through Amendment No. 202, are hereby incorporated into this license. Constellation Energy Generation, LLC shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- 3.
This license amendment is effective as of the date of its issuance and shall be implemented within 30 days.
FOR THE NUCLEAR REGULATORY COMMISSION Undine Shoop, Acting Chief Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Renewed Facility Operating License and Technical Specifications Date of Issuance: February 23, 2026 UNDINE SHOOP Digitally signed by UNDINE SHOOP Date: 2026.02.23 13:52:29 -05'00'
ATTACHMENT TO LICENSE AMENDMENT NO. 202 NINE MILE POINT NUCLEAR STATION, UNIT 2 RENEWED FACILITY OPERATING LICENSE NO. NPF-69 DOCKET NO. 50-410 Replace the following page of the Renewed Facility Operating License with the attached revised page. The revised page is identified by amendment number and contains marginal lines indicating the areas of change.
Remove Page Insert Page Page 4 Page 4 Replace the following pages of Appendix A, Technical Specifications, with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Remove Page Insert Page 3.3.6.1-7 3.3.6.1-7 3.7.7-1 3.7.7-2 3.7.7-3 Renewed License No. NPF-69 Amendment 117 through 201, 202 (1)
Maximum Power Level Constellation Energy Generation, LLC is authorized to operate the facility at reactor core power levels not in excess of 3988 megawatts thermal (100 percent rated power) in accordance with the conditions specified herein.
(2)
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, as revised through Amendment No. 202 are hereby incorporated into this license. Constellation Energy Generation, LLC shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
(3)
Fuel Storage and Handling (Section 9.1, SSER 4)*
- a. Fuel assemblies, when stored in their shipping containers, shall be stacked no more than three containers high.
- b. When not in the reactor vessel, no more than three fuel assemblies shall be allowed outside of their shipping containers or storage racks in the New Fuel Vault or Spent Fuel Storage Facility.
- c. The above three fuel assemblies shall maintain a minimum edge-to-edge spacing of twelve (12) inches from the shipping container array and approved storage rack locations.
- d. The New Fuel Storage Vault shall have no more than ten fresh fuel assemblies uncovered at any one time.
(4)
Turbine System Maintenance Program (Section 3.5.1.3.10, SER)
The operating licensee shall submit for NRC approval by October 31, 1989, a turbine system maintenance program based on the manufacturers calculations of missile generation probabilities.
(Submitted by NMPC letter dated October 30, 1989 from C.D. Terry and approved by NRC letter dated March 15, 1990 from Robert Martin to Mr. Lawrence Burkhardt, III).
- The parenthetical notation following the title of many license conditions denotes the section of the Safety Evaluation Report (SER) and/or its supplements wherein the license condition is discussed.
Primary Containment Isolation Instrumentation 3.3.6.1 NMP2 3.3.6.1-7 Amendment 91,140,147,164,186, 202 Table 3.3.6.1-1 (page 1 of 5)
Primary Containment Isolation Instrumentation FUNCTION APPLICABLE MODES OR OTHER SPECIFIED CONDITIONS REQUIRED CHANNELS PER TRIP SYSTEM CONDITIONS REFERENCED FROM REQUIRED ACTION C.1 SURVEILLANCE REQUIREMENTS ALLOWABLE VALUE
- 1. Main Steam Line Isolation a.
Reactor Vessel Water Level - Low Low Low, Level 1 1,2,3 2
D SR 3.3.6.1.1 SR 3.3.6.1.3 SR 3.3.6.1.4 SR 3.3.6.1.5 SR 3.3.6.1.6 SR 3.3.6.1.7 10.8 inches b.
Main Steam Line Pressure
- Low 1
2 E
SR 3.3.6.1.1 SR 3.3.6.1.3 SR 3.3.6.1.4 SR 3.3.6.1.5 SR 3.3.6.1.6 SR 3.3.6.1.7 814 psig c.
Main Steam Line Flow - High 1,2,3 2 per MSL D
SR 3.3.6.1.1 SR 3.3.6.1.3 SR 3.3.6.1.4 SR 3.3.6.1.5 SR 3.3.6.1.6 SR 3.3.6.1.7 184.4 psid d.
Condenser Vacuum - Low 1,2(a),
3(a) 2 D
SR 3.3.6.1.1 SR 3.3.6.1.3 SR 3.3.6.1.4 SR 3.3.6.1.5 SR 3.3.6.1.6 7.6 inches Hg vacuum e.
Deleted f.
Deleted g.
Deleted h.
Manual Initiation 1,2,3 4
G SR 3.3.6.1.6 NA (continued)
(a)
With any turbine stop valve not closed.
MSL Area Temperature 3.7.7 NMP 3.7.7-1 Amendment 202 3.7 PLANT SYSTEMS 3.7.7 Main Steam Line (MSL) Area Temperature LCO 3.7.7 The MSL Area temperature for each area in Table 3.7.7-1 shall be less than or equal to the limit APPLICABILITY:
MODES 1, 2, and 3.
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each MSL area.
CONDITION REQUIRED ACTION COMPLETION TIME A.
MSL Area temperature greater than the limit in Table 3.7.7-1 A.1 Initiate action to verify there is no leakage from the MSL pressure boundary.
AND A.2 Verify there is no leakage from the MSL pressure boundary.
Immediately Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter B.
Required Action and associated Completion Time not met B.1 Be in MODE 3.
AND B.2 Be in MODE 4 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> 36 hours
MSL Area Temperature 3.7.7 NMP 3.7.7-2 Amendment 202 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.7.1 Verify each MSL area temperature is less than or equal to the limit in Table 3.7.7-1 In accordance with the Surveillance Frequency Control Program
MSL Area Temperature 3.7.7 NMP 3.7.7-3 Amendment 202 Table 3.7.7-1 (page 1 of 1)
Main Steam Line Area Temperature Limits MSL Area Temperature Limit
- 1. Main Steam Line Tunnel 170.6 °F
- 2. Main Steam Line Tunnel Differential Temperature 71.7 °F
- 3. Main Steam Line Tunnel Lead Enclosure 175.6 °F
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REVISION TO THE TECHNICAL SPECIFCATIONS RELATED TO THE MAIN STEAM LINE AREA TEMPERATURE AMENDMENT NO. 202 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-69 CONSTELLATION ENERGY GENERATION, LLC NINE MILE POINT NUCLEAR STATION, UNIT 2 DOCKET NO. 50-410
1.0 INTRODUCTION
By letter dated July 18, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25199A162), as supplemented by [[letter::NMP2L2929, Response to Request for Additional Information for License Amendment Request to Revise Technical Specification 3.3.6.1-1 and Add New Technical Specification 3.7.7, Main Steam Line (MSL) Area Temperature|letter dated October 29, 2025]] (ML25302A442), Constellation Energy Generation, LLC (CEG, the licensee), requested changes to the technical specifications (TSs) for Nine Mile Point Nuclear Station (Nine Mile Point), Unit 2. The proposed amendment would remove Trip Function 1.e, Main Steam Line Tunnel Temperature - High, Trip Function 1.f, Main Steam Line Tunnel Differential Temperature - High, and Trip Function 1.g, Main Steam Line Tunnel Lead Enclosure Temperature - High, from Table 3.3.6.1-1, Primary Containment Isolation Instrumentation. In addition, the amendment would add a new TS, Main Steam Line (MSL) Area Temperature.
requiring manual action when the MSL area temperature is above the specified temperature limit.
The supplemental [[letter::NMP2L2929, Response to Request for Additional Information for License Amendment Request to Revise Technical Specification 3.3.6.1-1 and Add New Technical Specification 3.7.7, Main Steam Line (MSL) Area Temperature|letter dated October 29, 2025]], provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the U.S. Nuclear Regulatory Commission (NRC or the Commission) staffs original proposed no significant hazards consideration determination as published in the Federal Register on August 5, 2025 (90 FR 37574).
2.0 REGULATORY EVALUATION
2.1 Applicable Regulatory Requirements The NRC staff identified the following requirements as applicable in its review of the LAR:
Title 10 of the Code of Federal Regulations (10 CFR) 50.36(c)(2) requires that TSs include Limiting Conditions for Operation (LCOs). Pursuant to 10 CFR 50.36(c)(2)(i), LCOs are defined as the lowest functional capability or performance levels of equipment required for safe operation of the facility. The regulation also requires that when an LCO of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the TS until the condition can be met.
The regulation at 10 CFR 50.36(c)(3) requires that TS include items in the category of Surveillance Requirements (SRs), which are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the LCOs will be met.
The regulation at 10 CFR 50.36(a)(1) requires that a summary statement of the bases or reasons for such specifications, other than those covering administrative controls, be included in the application, but shall not become part of the technical specifications.
General Design Criterion (GDC) 30, Quality of reactor coolant pressure boundary, requires that components that are part of the Reactor Coolant Pressure Boundary (RCPB) be designed, fabricated, erected, and tested to the highest quality standards practical. GDC 30 also requires that means be provided for detecting and, to the extent practical, identifying the location of the source of reactor coolant leakage.
GDC 54, Piping systems penetrating containment, requires that piping systems penetrating primary reactor containment be provided with leak detection, isolation, and containment with redundancy, reliability, and performance capabilities commensurate with the safety importance of isolating these systems.
The regulation at 10 CFR 50.49, Environmental qualification of electric equipment important to safety for nuclear power plants, requires that electrical equipment important to safety be qualified to perform its safety functions under all postulated environmental conditions, including temperature, for the duration of its qualified life. The qualification process must demonstrate, prior to installation and throughout service life, that structures, systems, and components (SSCs) important to safety will perform their required functions under the most limiting environmental conditions associated with normal operation, anticipated operational occurrences, and design-basis accidents. If plant environmental conditions are revised, such as through changes to the operating temperature profile, the licensee must evaluate the impact on environmental qualification and update supporting analyses and documentation, as necessary, to maintain compliance with 10 CFR 50.49. This evaluation must consider cumulative environmental exposure and aging effects, and is not limited to initial type testing.
2.2 Proposed TS Changes
The proposed change revises Table 3.3.6.1-1 by deleting Trip Function 1.e, Main Steam Tunnel Temperature - High, Trip Function 1.f, Main Steam Line Tunnel Differential Temperature - High, and Trip Function 1.g, Main Steam Line Tunnel Lead Enclosure Temperature - High, and inserting the word Deleted in Table 3.3.6.1-1 for each deleted Trip Function. The licensee states that the deletion of these Functions does not require modification to existing SRs.
The proposed change also adds a new TS 3.7.7, Main Steam Line (MSL) Area Temperature.
The licensee states that the new LCO 3.7.7 requires the MSL area maximum temperatures to be less than or equal to the limits specified in the new Table 3.7.7-1, Main Steam Line Area Temperature Limits, and is applicable in Modes 1, 2, and 3, the same as existing Functions 1.e, 1.f, and 1.g. SR 3.7.7.1 requires verification that the MSL area temperatures are maintained in accordance with Table 3.7.7-1 on a frequency controlled by the Surveillance Frequency Control Program (SFCP). The initial frequency will be 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
In its LAR, the licensee states:
In the proposed new TS, if any MSL area maximum temperature exceeds the limits specified in Table 3.7.7-1 immediate action is required to verify there is no leakage from the MSL pressure boundary, and periodic verification is required every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter. If at any time it cannot be verified that there is no leakage from the MSL pressure boundary or if the periodic verification is not performed, the plant must be in MODE 3 (Hot Shutdown) within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and MODE 4 (Cold Shutdown) within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
3.0 TECHNICAL EVALUATION
3.1
System Description
In its LAR, the licensee provided the following system description:
The Main Steam Tunnel (MST) and Main Steam Tunnel Lead Enclosure (MSTLE) are monitored by dual-element thermocouples for sensing high ambient temperature in all these areas and high differential temperature between the inlet and outlet ventilation ducts in the MST. The temperature elements are located or shielded so that they are sensitive to air temperature only and not to radiated heat from hot piping or equipment. Increases in ambient and/or differential temperature indicate leakage of reactor coolant into the area. The monitors located in the MST and turbine building (MSTLE) have sensitivities suitable for detection of increases in ambient air temperature which are equivalent to reactor coolant leakage into the monitored areas of 25 gpm [gallons per minute] for MST and 45 gpm for MSTLE or less. The temperature trip setpoints are a function of room size and the type of ventilation provided. These monitors provide alarm, indication, and recording in the main control room, and trip the isolation logic to close selected isolation valves (e.g., the MST monitors close the Main Steam Isolation Valves [MSIV] and MSL drain isolation valves and other valves).
The large number of available indications and their dispersed arrangement near the steam lines provide confidence that a significant break would be detected rapidly and accurately in the MST.
Temperature and Differential Temperature - High [current Functions 1.e and 1.f respectively] is provided to detect a leak in a main steam line, and provides diversity to the high flow instrumentation. Temperature limits will be reached when a very small leak has occurred. If the small leak is allowed to continue without isolation, offsite dose limits may be reached. However, credit for these instruments is not taken in any transient of accident analysis in the USAR
[Updated Safety Analysis Report], since bounding analyses are performed for large breaks such as MSLBs [Main Steam Line Breaks].
The purpose of the MSL Area Temperature isolation function is to provide timely detection and isolation of small MSL leaks while maintaining sufficient margin above normal operating temperatures to avoid spurious isolation. The MSL Area Temperature instrumentation is part of the MSIV Group 1 isolation logic and isolates the normally open MSIVs and the normally closed MSL drain valves.
3.2 Evaluation of GDCs 30 and 54 Constellation stated in its LAR:
Means are provided for detecting reactor coolant leakage. The leak detection system consists of sensors and instruments to detect, annunciate, and, in some cases, isolate the RCPB from potential hazardous leaks before predetermined limits are exceeded. As described in USAR Section 5.2.5.1.3, small leaks are detected by temperature and pressure changes, increased frequency of sump pump operation, and measurement of airborne radioactivity in the primary containment atmosphere. In addition to these means of detection, large leaks are detected by flow rates in process lines and changes in reactor water level. The allowable leakage rates are based on the predicted and experimentally determined behavior of cracks in pipes, the ability to make up coolant system leakage, the normally expected background leakage due to equipment design, and the detection capability of the various sensors and instruments. The total leakage rate limit is established so that, in the absence of normal AC power concurrent with a loss of feedwater supply, makeup capabilities are provided by the Reactor Core Isolation Cooling (RCIC) system. While the leak detection system provides protection from small leaks, the Emergency Core Cooling System (ECCS) network provides protection for the full spectrum of possible discharges.
The following TS Table 3.3.6.1-1 Functions will continue to provide automatic MSL isolation:
1.a.
Reactor Vessel Water Level - Low, Low, Low, Level 1, 1.b.
Main Steam Line Pressure - Low, 1.c.
Main Steam Line Flow - High, and 1.d.
Condenser Vacuum - Low.
The NRC staff finds the deletion of Functions 1.e, 1.f, and 1.g from Table 3.3.6.1-1 acceptable because isolating the MSL would continue to be maintained by other TS provisions and because early detection that can be completed by the licensee provides margin to the critical crack size being reached. The proposed TS 3.7.7 would require a plant shutdown if a leak is detected, and Functions 1.a through 1.d, which are not being revised by this LAR, would continue to provide automatic MSL isolation. Therefore, the NRC staff finds the proposed change to delete Function 1.e, 1.f, and 1.g acceptable and that also finds that GDCs 30 and 54 would continue being met by the licensee.
3.3 Technical Specification Evaluation The licensee is proposing a new TS 3.7.7, MSL Area Temperature, which monitors the following MSL Areas with associated temperature limits (Table 3.7.7-1):
- 1. Main Steam Line Tunnel 170.6 °F
- 2. Main Steam Line Tunnel Differential Temperature 71.7 °F
- 3. Main Steam Line Tunnel Lead Enclosure 175.6 °F The temperatures included in Table 3.7.7-1 align with the limits for the Functions proposed for deletion:
1.e Main Steam Line Tunnel Temperature - High 170.6 °F 1.f Main Steam Line Tunnel Differential Temperature - High 71.7 °F 1.g Main Steam Line Tunnel Lead Enclosure Temperature - High 175.6 °F In its LAR, the licensee states:
The proposed LCO 3.7.7 requires that the MSL Area maximum temperature be less than or equal to the limits specified in Table 3.7.7-1. The leak detection isolation function is not required to satisfy any design basis event.
The Applicability of LCO 3.7.7 is MODES 1, 2, and 3. In MODES 1, 2, and 3, a Design Basis Accident (DBA) could result in the release of radioactive material into the MST if there is a leak in the MSLs. In MODES 4 and 5, the probability and consequences of a DBA with fission product release into the MST are reduced because of the pressure and temperature limitations in these conditions.
Therefore, maintaining MST temperature within limits is not required in MODES 4 or 5. The proposed Applicability is the same as the current Functions 1.e, 1.f, and 1.g.
The proposed SR 3.7.7.1 requires verification that MSL Area maximum temperature be less than or equal to the limits specified in Table 3.7.7-1. The Frequency is controlled under the SFCP, and the initial Frequency will be every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. As stated in SR 3.0.1, SRs must be met between performances of the Surveillance. If the MSL Area maximum temperature exceeds the limits specified in Table 3.7.7-1, operators will be alerted to take action.
The TS 3.7.7 Actions apply if any MSL Area temperature in Table 3.7.7-1 is exceeded. It requires immediate action to determine if there is leakage from the MSL pressure boundary.
MSL Area temperature may be elevated due to reasons other than an MSL pressure boundary leak, such as hot weather, reduced turbine building ventilation airflow or area cooling, and faulty temperature detectors. Verification will determine whether the elevated temperature is due to leakage from the MSL pressure boundary or another reason. Operations personnel are trained to perform the actions required to verify if leakage exists from the MSL pressure boundary, and no additional training or new operator actions will be required to perform the actions of TS 3.7.7.
If the elevated temperature is determined to not be due to leakage from the MSL pressure boundary and while MSL Area maximum temperature exceeds the limits specified in Table 3.7.7-1, the Actions require verification every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> that there is no leakage from the MSL pressure boundary. During Normal power operation, the monitored MST area has elevated radiation levels and adverse environmental conditions. The 12-hour Completion Time balances the small likelihood of a MSL pressure boundary leak occurring since the last verification against the risks of exposing workers to the radiological and environmental conditions to perform the verification.
If leakage from the MSL pressure boundary is detected or if the periodic verification is not performed, the actions require a plant shutdown. The plant must be brought to MODE 3 (Hot Shutdown) within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and MODE 4 (Cold Shutdown) within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The proposed times are consistent with the requirements of similar specifications and are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.
The NRC staff notes that the MSL area maximum temperature limits are not being changed.
The proposed LCO 3.7.7 and SR 3.7.7.1 requires verification that the current MSL area maximum temperatures are less than the limits in Table 3.7.7-1 on a frequency controlled by the SFCP and continues to be applicable in Modes 1, 2, and 3, which is the same as the existing Functions 1.e, 1.f, and 1.g. If an MSL area temperature exceeds its limit, the Actions require immediate verification that no MSL leak exists and continued verification every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter. The NRC staff finds that monitoring MSL area temperatures provides reasonable assurance that MSL pressure boundary leakage would be detected. In the event of a large MSL break, the MSIVs would automatically close on a Main Steam Line Flow - High signal. The NRC finds the 12-hour completion time reasonable based on operating experience and the low likelihood of MSL pressure boundary leakage. If it cannot be verified that there is not an MSL leak or if the periodic verification is not performed, TS 3.7.7 actions would require the plant to be in Mode 3 (Hot Shutdown) within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and Mode 4 (Cold Shutdown) within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
The licensee proposed new Bases for TS 3.7.7 and revisions to Bases affected by related TS changes. The NRC staff reviewed the proposed Bases and finds that they provide the reasons for the TS, consistent with 10 CFR 50.36(a)(1), and are consistent with the associated TS changes. Therefore, the NRC staff finds the proposed Bases acceptable.
The NRC staff finds that the proposed TS changes meet the requirements of 10 CFR 50.36(c)(2) because the instrumentation proposed for deletion from TS 3.3.6.1 is not credited in response or mitigation of any DBA analysis, and the new TS 3.7.7 provides operating restrictions that prevent or mitigate a MSL break if a small leak is detected. The TS Actions require appropriate corrective measures, including a plant shutdown, if leakage is identified. In addition, Functions 1.a through 1.d in TS Table 3.3.6.1-1, which are not revised, continue to provide automatic MSL isolation, consistent with the DBA analyses. The NRC staff also finds that the requirements of 10 CFR 50.36(c)(3) are satisfied because an appropriate surveillance is established to ensure that the necessary quality of systems and new LCO will be met. Based on the above evaluation, the NRC staff finds the proposed TS changes acceptable.
3.4 Environmental Qualification of Electric Equipment Important to Safety The environmental qualification (EQ) program for Nine Mile Point 2 is established and maintained in accordance with 10 CFR 50.49, which requires a documented program to demonstrate qualification of electric equipment important to safety for the applicable design basis environmental conditions.
In the LAR, the licensee stated that removing the automatic isolation function and adding a reactor shutdown requirement on high MSL area temperature will have no adverse effect on equipment qualification. Based on this statement, the NRC staff issued a request for additional information (RAI) on September 29, 2025 (ML25272A050), to obtain justification for how the determination in the LAR was reached and to understand how EQ zones have been or would be assessed when temperatures exceed the threshold, specified in new TS Table 3.7.7-1.
Additionally, with respect to inclusion of procedural guidance requiring post-threshold engineering review of qualified SSCs (i.e., manual actions), the NRC staff requested the licensee to provide supporting rationale describing how the surveillance and corrective action processes ensure timely identification and remediation of qualification issues to maintain the continued qualification of equipment. This rationale was requested to address how the program identifies and evaluates possible adverse impacts of sustained high temperatures on material integrity, functional performance, and qualified life of EQ equipment, and how these evaluations are integrated into decisions on operability, maintenance, and replacement to preserve compliance with EQ requirements.
In its October 29, 2025 (ML25302A442), response to the NRC staffs RAI, the licensee noted that it implements its EQ program with procedure CC-AA-203, Environmental Qualification Program, Revision 18. The licensees EQ Program Basis Document identifies EQ environmental zones and details their respective environmental parameters (temperature, pressure, humidity, radiation, chemical and water spray, and submergence), which are derived from design calculations updated with plant operating experience. These procedures provide the basis for the environmental conditions credited for qualification of equipment within the MSL area and other areas.
The licensee uses its site EQ procedures together with the Corrective Action Program (CAP) to identify, evaluate, and correct EQ-related concerns. Nine Mile Point 2 Procedure N2-OSP-LOG-S001, Shift Checks, Revision 42, is used to specifically monitor MSL Tunnel area temperatures during channel checks and, with the newly created TS SR 3.7.7.1, will continue to monitor MSL area temperature against the proposed LCO value.
According to the licensee, N2-OSP-LOG-S001 includes a procedural requirement to initiate an Issue Report and performance of an EQ evaluation if normal temperature thresholds are exceeded, thereby ensuring timely assessment of any impact on qualified life. According to the licensee, the temperature requiring EQ engineering review is below the limit specified in the new proposed LCO. Furthermore, if MSL area temperatures reach the proposed LCO limit, control room annunciators will activate and site procedures, including PI-AA-120, Issue Identification and Screening Process, Revision 13, would direct a prompt condition assessment that considers equipment performance and potential EQ impacts with the affected EQ environmental zones.
In response to the NRC staffs RAI, the licensee also stated that automatic MSL isolation on MSL area temperature is not assumed as the initiating event in any of the calculations that are inputs to the EQ program and the change from an automatic isolation to a manual action and procedurally required evaluation does not have an adverse impact on the EQ program. The licensee also noted that normal operating temperatures are not changed by the proposed amendment; therefore, no new EQ zones will be created.
Because automatic MSL isolation is not assumed as a credited mitigating feature in establishing EQ environmental conditions or qualified life, its removal does not change the timedependent temperature, pressure, humidity, radiation, chemical spray, or submergence profiles that form the basis of qualification per 10 CFR 50.49(e). Furthermore, the licensees EQ zones in and around the MSL area remain within the originally analyzed design basis conditions, and EQ equipment in these zones will continue to be controlled under the existing Nine Mile Point 2 EQ program.
The ongoing monitoring of MSL area temperatures through N2-OSP-LOG-S001 and TS SR 3.7.7.1, combined with CAP entry and EQ evaluation for temperature excursions, provides a structured mechanism to detect higher-than-expected temperatures and reassess qualified equipment life, if needed. If MSL area temperatures meet the criteria for entry into the proposed MSL Area Temperature LCO, the required engineering evaluation under PI-AA-120 ensures that any potential degradation in EQ equipment performance is identified and addressed consistent with 10 CFR 50.49(f) and (j), including maintenance of auditable EQ records.
The removal of automatic MSL isolation does not alter the defined EQ environmental zones, the underlying design basis environmental conditions, or the qualification bases for equipment within these zones. The existing EQ program, augmented by temperature monitoring, CAP requirements, and condition assessment procedures, continues to provide reasonable assurance that electric equipment important to safety in the MSL area will remain qualified to perform its safety functions under normal and accident conditions, consistent with the requirements of 10 CFR 50.49; therefore, the staff finds the proposed change acceptable.
3.5 Additional NRC Staff Review Considerations The NRC staff evaluated the proposed TS changes with respect to potential human factors considerations. The NRC staff notes that operations personnel are trained to perform the actions necessary to verify the existence of leakage from the MSL pressure boundary. The proposed changes, including new TS 3.7.7, do not introduce new operator actions or require additional training beyond that already established in plant procedures and training programs.
Accordingly, the NRC staff determined that the proposed changes do not involve new or revised human actions that would warrant a separate technical evaluation of human factors.
3.6 Technical Evaluation Summary and Conclusion The NRC staff has reviewed the proposed changes to the TSs and finds them acceptable for the reasons discussed below.
With respect to leak detection and isolation capability, the NRC staff finds that early leak detection capability is maintained and continues to provide reasonable assurance that leakage will be identified with sufficient margin to the critical crack size. Proposed TS 3.7.7 requires plant shutdown if leakage from the MSL pressure boundary is detected or if the periodic verification of the MST Area maximum temperature is not performed. In addition, TS Table 3.3.6.1-1 Functions 1.a through 1.d continue to provide automatic main steam line isolation on the existing credited signals. Therefore, the NRC staff concludes that the requirements of GDC 30 and GDC 54 continue to be satisfied.
The NRC staff finds that proposed TS 3.7.7 satisfies the requirements of 10 CFR 50.36(c)(2) and 10 CFR 50.36(c)(3), as discussed in Section 3.3 of this safety evaluation. The LCO establishes the lowest functional capability necessary for safe operation, and the associated surveillance requirements provide reasonable assurance that the LCO will be met.
The NRC staff finds the deletion of the trip functions from TS 3.3.6.1 acceptable because these functions are not credited in the accident analyses for mitigation of any DBA. Therefore, its removal does not adversely affect the plants ability to meet the applicable safety analyses assumptions.
With respect to EQ, the NRC staff finds that removal of the automatic MSL isolation function and addition of a reactor shutdown requirement on high MSL area temperature does not adversely affect the EQ of electrical equipment important to safety. Entry into the temperature conditions specified in TS Table 3.7.7-1 will require plant shutdown in accordance with the proposed TS 3.7.7. In addition, plant procedures provide for engineering evaluation of SSCs subject to elevated temperature conditions to assess actual environmental exposure and determine any necessary corrective actions to maintain qualification. Accordingly, the NRC staff concludes that the proposed license amendment does not adversely affect compliance with 10 CFR 50.49.
Based on the above, the NRC staff concludes that the proposed revision to TS Table 3.3.6.1-1 to eliminate the requirements for automatic MSL isolation (Functions 1.e. 1.f, and 1.g) is acceptable. The NRC staff also concludes that the proposed new TS 3.7.7, which requires temperature monitoring and plant shutdown upon detection of excessive MSL leakage, is acceptable.
4.0 STATE CONSULTATION
In accordance with the Commissions regulations, the New York State official was notified of the proposed issuance of the amendment on January 26, 2026. On January 30, 2026, the State official confirmed that the State of New York had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding published in the Federal Register on August 5, 2025 (90 FR 37574).
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: D. Scully, NRR J. Cintron-Rivera, NRR Date: February 23, 2026
ML26048A478 NRR-058 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL3/LA NRR/DSS/SCPB/BC NAME RGuzman SLent MValentin DATE 2/17/2026 2/18/2026 2/18/2026 OFFICE NRR/DEX/ELTB/BC NRR/DEX/EICB/BC (A)
NRR/DSS/STSB/BC NAME JPaige SDarbali SMehta DATE 2/19/2026 2/20/2026 2/20/2026 OFFICE NRR/DORL/LPL1/BC (A)
NRR/DORL/LPL1/PM NAME UShoop RGuzman DATE 2/23/2026 2/23/2026