ML26009A051

License Amendment Request for Changes to the Technical Specification Surveillance Requirement 4.6.1.7 to Delete Number of Installed Sensors

ML26009A051
Person / Time
Site:	Limerick
Issue date:	01/09/2026
From:	Para W Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
LG-26-025
Download: ML26009A051 (0)

Text

200 Energy Way Kennett Square, PA 19348 www.constellation.com LG-26-025 10 CFR 50.90 January 9, 2026 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353

Subject:

License Amendment Request for Changes to the Technical Specification Surveillance Requirement 4.6.1.7 to Delete Number of Installed Sensors In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Constellation Energy Generation, LLC (CEG), proposes changes to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. NPF-39 and NPF-85 for Limerick Generating Station (LGS), Units 1 and 2, respectively.

The proposed changes are to modify the Surveillance Requirements (SR) to remove the specifics of the acceptable means to determine drywell average air temperature and relocate to the TS Bases. The TS Bases will describe acceptable means of determining drywell average air temperature, including if there are no functional sensors on an elevation.

Specifically, the proposed changes remove the volumetric average of the temperatures at the following locations and shall be from SR 4.6.1.7. The table below the SR listing Approximate Elevations, Number of Installed Sensors, and an asterisk note requiring at least one reading from each elevation are also removed.

The proposed changes are consistent with NUREG-1433 Standard Technical Specifications -

General Electric BWR/4 Plants, Revision 5, SR 3.6.1.5.1.

Upon approval of this proposed request, additional information will be added to the Technical Specification Bases.

CEG has concluded that the proposed changes present no significant hazards consideration under the standards set forth in 10 CFR 50.92, "Issuance of amendment."

The proposed changes have been reviewed by the LGS Plant Operations Review Committee in accordance with the requirements of the CEG Quality Assurance Program.

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 January 9, 2026 Page 2 provides the evaluation of the proposed changes. Attachment 2 provides a copy of the marked-up TS pages that reflect the proposed changes. Attachment 3 provides an information only copy of the marked-up TS Bases pages that reflect the proposed changes.

CEG requests approval of the proposed amendments by August 31, 2026. Upon approval, the proposed changes will be implemented within 60 days. This implementation period will provide adequate time for the affected station documents to be revised using the appropriate change control mechanisms.

In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," paragraph (b), CEG is notifying the Commonwealth of Pennsylvania of this application for license amendment by transmitting a copy of this letter and its attachments to the designated State Official.

There are no new regulatory commitments contained in this submittal.

Should you have any questions concerning this submittal, please contact Lane Oberembt at 267-533-5301.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 9th day of January 2026.

Respectfully, Wendi Para Sr. Manager, Licensing Constellation Energy Generation, LLC Attachments:

1. Evaluation of Proposed Changes

2. Markup of Proposed Technical Specification Pages

3. Markup of Technical Specifications Base Pages - For Information Only cc:

USNRC Region 1, Regional Administrator w/ attachments USNRC Senior Resident Inspector - LGS USNRC Project Manager, LGS Director, Bureau of Radiation Protection - Pennsylvania Department of Environmental Protection Para, Wendi E 2026.01.09 08:28:48

-05'00'

ATTACHMENT 1 License Amendment Request Limerick Generating Station, Units 1 and 2 Docket Nos. 50-352 and 50-353 EVALUATION OF PROPOSED CHANGES

Subject:

License Amendment Request for Changes to the Technical Specification Surveillance Requirement 4.6.1.7 to Delete Number of Installed Sensors 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

3.0 TECHNICAL EVALUATION

3.1 Design Basis and System Description 3.2 Reason for Proposed Changes to TS 3.6.1.7 3.3 Basis for Proposed Changes to TS 3.6.1.7 3.4 Relocation of Temperature Sensor Information to Technical Specification Bases 3.6.1.7 3.5 Impact to Detection of Abnormal Leakage Within the Primary Containment 3.6 Impact to Containment Safety Analyses 3.7 Summary of Proposed Changes to TS 3.6.1.7

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 No Significant Hazards Consideration 4.4 Conclusions

6.0 REFERENCES

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 2

1.0

SUMMARY

DESCRIPTION In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Constellation Energy Generation, LLC (CEG), proposes changes to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. NPF-39 and NPF-85 for Limerick Generating Station (LGS), Units 1 and 2, respectively.

The proposed changes remove the volumetric average of the temperatures at the following locations and shall be from Surveillance Requirement (SR) 4.6.1.7. The table below the SR listing Approximate Elevations, Number of Installed Sensors, and asterisk note requiring at least one reading from each elevation is also removed.

The proposed changes are to modify the SR to remove the specifics of the acceptable means to determine drywell average air temperature and relocate to the TS Bases. The TS Bases will describe acceptable means of determining drywell average air temperature, including if there are no functional sensors on an elevation.

The proposed changes are consistent with NUREG-1433 Standard Technical Specifications -

General Electric BWR/4 Plants, Revision 5 (Reference 1), SR 3.6.1.5.1.

2.0 DETAILED DESCRIPTION LGS Units 1 and 2, SR 4.6.1.7 currently read:

The drywell average air temperature shall be the volumetric average of the temperatures at the following locations and shall be determined to be within the limit in accordance with the Surveillance Frequency Control Program:

Approximate Elevation Number of Installed Sensors*

a.

330 3

b.

320 3

c.

260 3

d.

248 6

• At least one reading from each elevation is required for a volumetric average calculation.

The changes requested by this amendment request are described below for both LGS Units 1 and 2:

1. Proposed SR 4.6.1.7 states:

The drywell average air temperature shall be the volumetric average of the temperatures at the following locations and shall be determined to be within the limit in accordance with the Surveillance Frequency Control Program:.

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353

2. The table below SR 4.6.1.7 will be deleted:

Approximate Elevation Number of Installed Sensors*

a.

330 3

b.

320 3

c.

260 3

d.

248 6

3. The asterisk at the bottom of the page and the associated statement will be deleted:

• At least one reading from each elevation is required for a volumetric average calculation.

See Attachment 2 for the marked-up TS pages.

3.0 TECHNICAL EVALUATION

3.1 Design Basis and System Description The primary containment is divided by a horizontal diaphragm slab into two major volumes: the drywell and the suppression chamber. The drywell encloses the reactor vessel, reactor recirculation system, and associated piping and valves. The suppression chamber stores a large volume of water. The primary containment is in the form of a truncated cone over a cylindrical section, with the drywell being the upper conical section and the suppression chamber being the lower cylindrical section. These two sections comprise a structurally integrated, reinforced concrete pressure vessel, lined with welded steel plate and provided with a steel domed head for closure at the top of the drywell.

The drywell air cooling system is designed to remove heat from the drywell during normal plant operation (non-safety related function) and circulate a thoroughly mixed atmosphere under accident conditions (safety related function). The system is designed to limit the temperature inside the drywell during normal plant operation to an average of 150°F, with the maximum not to exceed 150°F in areas containing environmentally qualified equipment, and not to exceed 160°F in all other areas.

The drywell air cooling system is designed to limit the temperature inside the drywell, in the event of a loss of offsite power and reactor scram, to 186°F in general drywell areas and to 210°F in the area below the vessel. The system is also designed to prevent concrete structures within the primary containment from exceeding their maximum design temperature during normal operation.

The drywell air cooling system includes eight unit-coolers; 1(2)A-V212, 1(2)B-V212, 1(2)C-V212, 1(2)D-V212, 1(2)E-V212, 1(2)F-V212, 1(2)G-V212, 1(2)H-V212. Each unit-cooler 3

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 contains two redundant cooling coils and two redundant fans. One fan in each drywell unit cooler is normally operating, with the second fan in standby. The standby fan starts automatically upon loss of the lead fan, sensed by a low air flow switch in the discharge duct from the unit cooler.

The drywell unit coolers are located in the lower section of the drywell between elevation 243 and elevation 265 and are arranged around the circumference of the drywell as shown in UFSAR Figure 9.4-8. Two of the unit coolers are provided with duct-work on both the suction and discharge sides, while the remaining six unit coolers have discharge duct-work only.

Return air enters the latter unit coolers directly from the surrounding air space. Each unit cooler supplies a specific area of the drywell. The unit coolers deliver a total of 56,000 cfm of conditioned air to the various elevations within the drywell.

Four of the unit coolers, 1(2)A-V212, 1(2)B-V212, 1(2)G-V212, and 1(2)H-V212, are in operation following a LOCA to maintain the drywell in a thoroughly mixed condition. The other four-unit coolers are non-safety related.

Drywell temperature monitoring provides an indirect method of detecting Reactor Coolant Pressure Boundary (RCPB) leakage. The drywell area unit coolers circulate and cool the drywell atmosphere to maintain the drywell at its design operating temperature. Cooling water is supplied to the unit coolers by the Drywell Chilled Water System (DCWS). A temperature rise in the drywell will indicate the presence of reactor coolant or steam leakage and is detected by the drywell temperature monitors located at various elevations and at the inlet and outlet of the air coolers.

TS 3.6.1.7 specifies that the drywell average air temperature shall not exceed 145°F during OPERATIONAL CONDITIONS 1, 2 and 3. With a temperature greater than 145°F, reduce the temperature to within the limit within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The supporting TS Bases states that the limitation on drywell average air temperature ensures that the containment peak air temperature does not exceed the design temperature of 340°F during steam line break conditions and is consistent with the safety analysis.

SR 4.6.1.7 specifies that the drywell average air temperature shall be the volumetric average of the temperatures at four elevations, with three sensors installed at drywell elevations 260, 320 and 330, and six sensors installed at drywell elevation 248. An asterisk note specifies at least one reading from each elevation is required for a volumetric average calculation. The current drywell volumetric average air temperature calculation applies a nominal weighting to the average of the temperature readings for a given elevation.

3.2 Reason for Proposed Changes to TS 3.6.1.7 In a scenario where three sensors are lost on an elevation (260, 320 or 330) [or six sensors on elevation 248] and a single sensor is unable to be repaired, TS 3.6.1.7 would require an unwarranted unit shutdown. The loss of the temperature readings on an elevation does not correlate to an actual change or increase in drywell average air temperature. The loss of 4

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 5

temperature sensors on an elevation only affects temperature indication and has no effect or control function related to drywell air temperature. CEG proposes changes to TS 3.6.1.7 to avoid an unwarranted unit shutdown driven by loss of temperature sensing equipment, and not due to an actual drywell average air temperature above 145°F.

Although the temperature sensors are historically reliable, their location (inside containment) prevents repairs while the unit is operating. There have been instances of the temperature indicators (located in the main control room) being erratic, but these are able to be repaired on-line. However, some components are located inside the drywell, and therefore, inaccessible for repair with the unit at power.

3.3 Basis for Proposed Changes to TS 3.6.1.7 To avoid an unwarranted unit shutdown due to loss of temperature sensing equipment only, CEG proposes to remove the requirement to have at a minimum, one reading from each elevation as a singular basis for initiating a unit shutdown. CEG operating procedures will be revised to specify the actions to take upon loss of all temperature readings for an elevation.

Operations will perform a review of the elevations average temperature and determine a conservative-but-representative value to substitute.

Operations will determine a representative average air temperature for an elevation with no valid sensors in the drywell air temperature monitoring procedure.

Below is an example of the methodology:

The average difference between an elevation that now has no valid sensors, and a reference elevation will be determined using the previous three days of data.

This average deviation, or offset, will be added or subtracted from the reference elevation to determine temperature of an elevation with no valid sensors. Additional conservatism would be added to the offset to ensure a bounding substitute to determine the calculated temperature.

This calculated temperature for an elevation with no valid sensors will then be used as an input to compute the overall drywell volumetric temperature.

For subsequent days, the same offset plus conservatism will continue to be used.

Since the drywell air temperatures trend similarly, and since the drywell is not subject to large temperature variations on a day-to-day basis, use of a substitute value referenced to another elevation is an acceptable way to represent the average temperature for an elevation. This method ensures that the day-to-day fluctuations in temperature continue to be represented in the drywell average air temperature. The conservatism applied to an elevation with no valid sensors provides added margin that the drywell average temperature remains below 145°F.

The drywell air temperatures are influenced by bulk and local factors including heat flux from nearby equipment, unit cooler air flows, and the location and condition of the unit coolers and associated ductwork. The elevation 248, 260, 320 and 330 average air temperature and overall drywell average air temperature was reviewed over the previous three summer periods

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 6

and verified to trend together within an operating cycle; that is, they trend up or down in a similar way. The temperature differences between elevations were determined not to be seasonally dependent. In addition, due to the large thermal masses in the drywell, temperature trends are relatively stable and generally fluctuate only one to two degrees Fahrenheit on a day-to-day basis. Over time, the conservatism may not adequately bound the deviations between elevations. The procedure will direct Engineering to evaluate the historical temperature deviations and confirm the conservatism being used is bounding for longer periods of operation to assess the average air temperature for an elevation with no valid sensors.

The proposed changes delineate a very unlikely scenario that would require entering the proposed methodology for determining drywell bulk average air temperature. Station history has demonstrated that the current SR of having no valid sensors operable on a single elevation, resulting in entering the Limiting Condition for Operation (LCO) shutdown action statement, has not occurred in the last ten (10) years. If the unlikely scenario of no valid sensors on an elevation were to occur, the proposed method would be adequate to accurately monitor bulk drywell average air temperature without requiring an unnecessary shutdown.

3.4 Relocation of Temperature Sensor Information to Technical Specification Bases 3.6.1.7 SR 4.6.1.7 specifies that the drywell average air temperature shall be the volumetric average of the temperatures at four elevations, with three (3) sensors installed at elevations 260, 320 and 330, and six (6) sensors installed at elevation 248. CEG proposes to relocate the information regarding the number of installed sensors at each elevation to a licensee-controlled program document. Relocating the temperature sensors, specific elevation information and the description of volumetric average temperature to the TS Bases is more suitable for awareness of the drywell air temperature system equipment and locations, without unnecessarily impacting TS LCO actions.

3.5 Impact to Detection of Abnormal Leakage Within the Primary Containment Systems for quantifying leakage from the RCPB are necessary to provide prompt and quantitative information to operators to permit them to take immediate corrective action.

Leakage from the RCPB inside the drywell is detected by four independently monitored variables which include:

drywell sump flow monitoring equipment with the required reactor coolant system leakage detection instrumentation (i.e., the drywell floor drain sump flow monitoring system, or the drywell equipment drain sump monitoring system with the drywell floor drain sump overflowing to the drywell equipment drain sump),

drywell gaseous radioactivity, drywell unit cooler condensate flow rate, and drywell pressure and temperature levels.

The primary means of quantifying RCPB leakage in the drywell is the drywell sump monitoring system for UNIDENTIFIED LEAKAGE and the drywell equipment drain tank flow monitoring system for IDENTIFIED LEAKAGE.

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 The drywell temperature and pressure monitoring systems provide an indirect method of detecting RCPB leakage. A temperature and/or pressure rise above the normally indicated value may be indicative of a reactor coolant and/or steam leak.

Drywell temperature readings are one of four diverse methods Operations uses to monitor for leakage in the drywell. If all temperature sensors are lost on an elevation, Operations has other independently monitored variables to monitor for leakage in the drywell. Therefore, the proposed changes are acceptable and will not impact the ability to monitor and detect RCPB leakage in the drywell.

3.6 Impact to Containment Safety Analyses The TS 3.6.1.7 Bases states that the limitation on drywell average air temperature ensures that the containment peak air temperature does not exceed the design temperature of 340°F during steam line break conditions and is consistent with the safety analysis. The drywell average air temperature is an input to the containment analysis for steam line break conditions. The input value used in the analysis is 150°F. The TS drywell average air temperature limit of 145°F provides margin to the drywell air temperature value used in the containment analysis for steam line break conditions. As described above, the proposed changes for loss of all temperature sensors for an elevation would result in a calculated temperature higher than the actual drywell average air temperature. As a result, the proposed changes to TS 3.6.1.7 are conservative and ensure the containment design air temperature of 340°F will not be exceeded in a steam line break accident scenario.

3.7 Summary of Proposed Changes to TS 3.6.1.7 Constellation proposes to remove the requirement to have one drywell temperature reading from each elevation. This change would avoid a unit shutdown driven by loss of temperature sensing equipment, and not due to an actual drywell average air temperature above 145°F.

Constellation operating procedures would specify the actions to take upon loss of all temperature readings for an elevation. An average deviation or offset value would be applied to a reference elevation to represent the average drywell temperature for an elevation with no valid temperature sensors. In addition, the conservatism applied to the reference temperature for an elevation having no valid sensors provides additional margin that the drywell average temperature remains conservative. The proposed changes are acceptable because the use of an average deviation or offset value referenced to another elevation is an acceptable way to represent the average temperature for the elevation and will not impact the ability of Operations to monitor for RCPB leakage in the drywell. The proposed changes maintain margin to the drywell temperature limit of 145°F which ensures the containment design air temperature of 340°F will not be exceeded in a steam line break accident scenario. Relocating the drywell air temperature sensors and drywell elevation information to the TS Bases is consistent with NUREG-1433/BWR-4 Revision 5.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 7

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 The following applicable regulations and regulatory requirements were reviewed in development of this submittal:

10 CFR 50.36, Technical specifications, part (c)(2)(ii): (1) installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary; (2) a process variable, design feature, or operating restriction that is an initial condition of a design basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier; (3) a structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier; and (4) a structure, system, or component which operating experience or probabilistic risk assessment (PRA) has shown to be significant to public health and safety. As a result, TS requirements which satisfy any of the criteria in 10 CFR 50.36 must be retained in the TS.

10 CFR Part 50 Appendix A General Design Criterion (GDC) 38 Containment Heat Removal. A system to remove heat from the reactor containment shall be provided. The system safety function shall be to reduce rapidly, consistent with the functioning of other associated systems, the containment pressure and temperature following any LOCA and to maintain them at acceptably low levels. Suitable redundancy in components and features and suitable interconnections, leak detection, isolation, and containment capabilities shall be provided to assure that for onsite electric power system operation (assuming offsite power is not available) and for offsite electric power system operation (assuming onsite power is not available) the system safety function can be accomplished, assuming a single failure.

10 CFR Part 50 Appendix A General Design Criterion (GDC) 50 Containment design basis. The reactor containment structure, including access openings, penetrations, and the containment heat removal system shall be designed so that the containment structure and its internal compartments can accommodate, without exceeding the design leakage rate and with sufficient margin, the calculated pressure and temperature conditions resulting from any loss-of-coolant accident. This margin shall reflect consideration of (1) the effects of potential energy sources which have not been included in the determination of the peak conditions, such as energy in steam generators and as required by § 50.44 energy from metal-water and other chemical reactions that may result from degradation but not total failure of emergency core cooling functioning, (2) the limited experience and experimental data available for defining accident phenomena and containment responses, and (3) the conservatism of the calculational model and input parameters.

CEG has determined that the proposed change does not require any exemptions or relief from regulatory requirements, other than the TS, and does not affect conformance with any regulatory requirements/criteria.

4.2 Precedent The proposed changes are consistent with NUREG-1433 Standard Technical Specifications -

General Electric BWR/4 Plants, Revision 5, SR 3.6.1.5.1.

8

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 9

4.3 No Significant Hazards Consideration In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Constellation Energy Generation, LLC (CEG), proposes changes to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. NPF-39 and NPF-85 for Limerick Generating Station (LGS), Units 1 and 2, respectively.

The proposed changes remove the volumetric average of the temperatures at the following locations and shall be from Surveillance Requirement (SR) 4.6.1.7. The table below the SR listing Approximate Elevations, Number of Installed Sensors, and asterisk note requiring at least one reading from each elevation is also removed. The Technical Evaluation (Section 3.0) provides adequate justification to obtain accurate drywell temperature and maintain it below the TS 3.6.1.7 required limit of 145°F.

CEG has evaluated the proposed changes, using the criteria in 10 CFR 50.92, "Issuance of amendment," and has determined that the proposed changes do not involve a significant hazards consideration. The following information is provided to support a finding of no significant hazards consideration.

1.

Do the proposed changes involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The proposed changes do not alter any of the previously evaluated accidents in the UFSAR. The proposed changes move the temperature element sensors and elevation information into the TS Bases. In the unlikely event that all sensors on an elevation become inoperable, an engineering methodology will be initiated to determine average drywell air temperature using operating drywell air temperature elements. The proposed changes do not affect any of the initiators of previously evaluated accidents in a manner that would increase the likelihood of the event.

Therefore, the proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

2.

Do the proposed changes create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed changes will not introduce any new operating modes, safety-related equipment lineups, accident scenarios, system interactions, or failure modes that would create a new or different type of accident. Failure(s) of all temperature elements on an elevation will initiate an engineering methodology to conservatively calculate drywell air temperature. If the results of the calculation conclude that drywell average air temperature is >145°F, then TS 3.6.1.7 Limiting Condition for Operation (LCO) will be entered.

License Amendment Request Proposed Changes to SR 4.6.1.7 Docket Nos. 50-352 and 50-353 10 Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.

3.

Do the proposed changes involve a significant reduction in a margin of safety?

Response: No The proposed changes do not reduce a significant margin of safety. The proposed changes relocate temperature element sensors and elevations into the TS Bases and removes the requirement of having at least one temperature on an elevation as a requirement for meeting TS SR 4.6.1.7. A conservative engineering methodology for determining average drywell air temperature with the remaining sensors would be used in the unlikely event that all sensors on an elevation are inoperable. If the results of the calculation conclude that drywell average air temperature is >145°F, then TS 3.6.1.7 LCO will be entered.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Based on the above evaluation, CEG concludes that the proposed amendments present no significant hazards consideration under the standards set forth in 10 CFR 50.92, paragraph (c),

and accordingly, a finding of "no significant hazards consideration" is justified.

4.4 Conclusions In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or the health and safety of the public.

5.0 ENVIRONMENTAL CONSIDERATION

CEG has determined that the proposed changes would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed changes do not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed changes meet the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment needs to be prepared in connection with the proposed changes.

6.0 REFERENCES

1. NUREG-1433 Standard Technical Specifications - General Electric BWR/4 Plants, Revision 5

2. LGS UFSAR (Various sections)

ATTACHMENT 2 License Amendment Request Limerick Generating Station, Units 1 and 2 Docket Nos. 50-352 and 50-353 License Amendment Request for Proposed Changes to the Technical Specification Surveillance Requirement 4.6.1.7 to Delete Number of Installed Sensors Markup of Proposed Technical Specification Pages Unit 1 TS Page 3/4 6-10 Unit 2 TS Page 3/4 6-10

CONTAINMENT SYSTEMS DRYWELL AVERAGE AIR TEMPERATURE LIMITING CONDITION FOR OPERATION 3.6.1.7 Drywell average air temperature shall not exceed 145°F.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2, and 3.

ACTION:

With the drywell average air temperature greater than 145°F, reduce the average air temperature to within the limit within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.6.1.7 The drywell average air temperature shall be the volumetric average of the temperatures at the following locations and shall be determined to be within the limit in accordance with the Surveillance Frequency Control Program:

Approximate Number of Elevation Installed Sensors*

a.

330' 3

b.

320' 3

c.

260' 3

d.

248' 6

• At least one reading from each elevation is required for a volumetric average calculation.

LIMERICK - UNIT 1 3/4 6-10 Amendment No. 29, 159, 186

CONTAINMENT SYSTEMS DRYWELL AVERAGE AIR TEMPERATURE LIMITING CONDITION FOR OPERATION 3.6.1.7 Drywell average air temperature shall not exceed 145°F.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2, and 3.

ACTION:

With the drywell average air temperature greater than 145°F, reduce the average air temperature to within the limit within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.6.1.7 The drywell average air temperature shall be the volumetric average of the temperatures at the following locations and shall be determined to be within the limit in accordance with the Surveillance Frequency Control Program:

Approximate Number of Elevation Installed Sensors*

a.

330' 3

b.

320' 3

c.

260' 3

d.

248' 6

• At least one reading from each elevation is required for a volumetric average calculation.

LIMERICK - UNIT 2 3/4 6-10 Amendment No. 121, 145, 147, 153

ATTACHMENT 3 License Amendment Request Limerick Generating Station, Units 1 and 2 Docket Nos. 50-352 and 50-353 License Amendment Request for Proposed Changes to the Technical Specification Surveillance Requirement 4.6.1.7 to Delete Number of Installed Sensors Markup of Technical Specification Bases Pages - For Information Only Unit 1 TS Bases Page B 3/4 6-2 Unit 2 TS Bases Page B 3/4 6-2

Insert A

Insert A

Insert A The following table provides the approximate elevation and number of installed temperature sensors.

Approximate Elevation Number of Installed Sensors

a.

330 3

b.

320 3

c.

260 3

d.

248 6

The surveillance requirement verifies that the drywell average air temperature is within the LCO limit and ensures that operation remains within the limits assumed for the primary containment analyses. Drywell air temperature is monitored in various quadrants and at various elevations.

Due to the shape of the drywell, a volumetric average is used to determine an accurate representation of the actual average temperature.

In the event all temperature elements are lost for a specific elevation, Operations will determine a conservative-but-representative average air temperature for an elevation with no valid sensors as directed by the drywell air temperature monitoring procedure. The average difference between an elevation that has no valid sensors, and a reference elevation, will be determined using the most recent historical data. This average deviation, or offset, will be added or subtracted from the reference elevation to determine the temperature of an elevation with no valid sensors. Additional conservatism will then be added to the offset to ensure a bounding substitute to determine the calculated average air temperature. This calculated average air temperature for an elevation with no valid sensors will then be used as an input to compute the overall drywell volumetric temperature.