RS-25-156, Request for Amendment to Technical Specifications Table 3.3.6.1-1, Primary Containment Isolation Instrumentation
| ML25346A245 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 12/12/2025 |
| From: | Steinman R Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| RS-25-156 | |
| Download: ML25346A245 (0) | |
Text
4300 Winfield Road Warrenville, IL 60555 630 657 2000 Office RS-25-156 10 CFR 50.90 December 12, 2025 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 LaSalle County Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374
Subject:
Request for Amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Constellation Energy Generation, LLC (CEG), requests an amendment to the Renewed Facility Operating License Nos. NPF-11 and NPF-18 for LaSalle County Station (LSCS), Units 1 and 2. Specifically, CEG requests the amendment of Technical Specification (TS) Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" to add the requirement to perform a Channel Check in accordance with Surveillance Requirement (SR) 3.3.6.1.1 to the Main Steam Line FlowHigh (Function 1.c). The proposed change is the result of planned replacement of existing plant equipment with equipment that has the capability of permitting the performance of a Channel Check with the plant in MODES 1, 2 and 3. The proposed change is consistent with the wording specified in NUREG-1434, "Standard Technical Specifications General Electric Plants, BWR/6," Revision 5, dated September 2021. provides an evaluation of the proposed changes. Attachment 2 provides the marked up TS page.
CEG has concluded that the proposed change presents no significant hazards considerations under the standards set forth in 10 CFR 50.92, "Issuance of Amendment."
The proposed changes have been reviewed by LSCS Plant Operations Review Committee in accordance with the requirements of the CEG Quality Assurance Program.
There are no regulatory commitments contained in this submittal.
CEG requests approval of the proposed amendments by January 30, 2026. Once approved, the amendments shall be implemented prior to entry into MODE 2 during restart from the Unit 1 spring refueling outage of February 2026. The Unit 2 Channel Checks will commence after equipment installation during the spring refueling outage of February 2027.
U.S. Nuclear Regulatory Commission December 12, 2025 Page 2 In accordance with 10 CFR 50.91, "Notice for public comment; State consultation,"
paragraph (b), a copy of this application, with attachments, is being provided to the designated State Officials.
If you should have any questions regarding this submittal, please contact Jared Smith at 7792316155.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 12th day of December 2025.
Respectfully, Rebecca L. Steinman Sr. Manager Licensing Constellation Energy Generation, LLC Attachments:
- 1. Evaluation of Proposed Change - Request for Amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation"
- 2. Markup of Technical Specifications Page cc:
NRC Regional Administrator - Region III NRC Senior Resident Inspector - LaSalle County Station Illinois Emergency Management Agency - Division of Nuclear Safety Steinman, Rebecca Lee Digitally signed by Steinman, Rebecca Lee Date: 2025.12.12 14:12:43 -06'00'
ATTACHMENT 1
Subject:
Request for Amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" 1.0
SUMMARY
DESCRIPTION............................................................................................... 1 2.0 DETAILED DESCRIPTION................................................................................................ 1
3.0 TECHNICAL EVALUATION
............................................................................................... 1
4.0 REGULATORY EVALUATION
........................................................................................... 2 4.1 Applicable Regulatory Requirements...................................................................... 2 4.2 Precedent................................................................................................................ 2 4.3 No Significant Hazards Consideration.................................................................... 3 4.4 Conclusions............................................................................................................ 4
5.0 ENVIRONMENTAL CONSIDERATION
............................................................................. 4
6.0 REFERENCES
................................................................................................................... 5
ATTACHMENT 1 Request for Amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" 1
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), requests an amendment to the Renewed Facility Operating License Nos. NPF-11 and NPF-18 for LaSalle County Station (LSCS), Units 1 and 2.
Specifically, CEG requests to amend Technical Specifications (TS) Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation."
2.0 DETAILED DESCRIPTION The proposed amendment revises TS Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation," which documents the Surveillance Requirements (SRs) for Primary Containment Isolation Instrumentation Functions. Specifically, the Function 1.c "Main Steam Line FlowHigh" will be revised to add surveillance requirement 3.3.6.1.1 (Perform CHANNEL CHECK).
Table 4.3.2.1-1 documenting the SR for this Function in the original LSCS TS was amended in 1984 (Reference 6.3) to remove the requirement to perform a Channel Check because the newly-replaced environmentally-qualified (EQ) instruments did not have the capability of performing the surveillance. As described in Section 3 of this request, this new replacement equipment will have the capability of supporting the performance of a Channel Check.
The decision to add the Channel Check surveillance was made for consistency with the Standard TS in NUREG-1434, "Standard Technical Specifications General Electric Plants, BWR/6," Revision 5 (Reference 6.1) and also in accordance with guidance provided in Information Notice 88-51, Failures of Main Steam Isolation Valves (MSIVs) (Reference 6.2),
which states that licensees should carefully consider the adequacy of main steam line isolation surveillances supporting operability determinations of MSIVs. This added surveillance allows a quick and easy method for detecting gross instrument failures of the MSL flow differential pressure switches between the surveillance intervals of other more extensive tests (e.g.,
monthly Channel Functional Tests) which would detect a failure.
See Attachment 2 for the proposed markup of the TS page.
3.0 TECHNICAL EVALUATION
The existing design of the Primary Containment Isolation Instrumentation for the Main Steam Line FlowHigh Main Steam Line (MSL) isolation Function consists of four differential pressure switches for each steam line that sense the pressure difference across the flow element in that line. The MSL FlowHigh Function closes inboard and outboard MSIVs and main steam line drain valves in response to high flow sensed at these differential pressure switches. The existing differential pressure switches do not have the capability to allow a Channel Check to be performed in MODES 1, 2 and 3. The new differential pressure trip units have analog indication that permits a Channel Check to be performed in the above modes. Therefore, LSCS is requesting that TS Table 3.3.6.1-1 be modified to specify that a Channel Check be performed in
ATTACHMENT 1 Request for Amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" 2
accordance with SR 3.3.6.1.1, to be performed in MODES 1, 2 and 3, consistent with the guidance contained in NUREG-1434 (Reference 6.1).
4.0 REGULATORY EVALUATION
4.1 Applicable Regulatory Requirements 10 CFR 50.36(c)(2)(ii)(c), "Criterion 3.", requires that 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 be included in the TS.
TS Table 3.3.6.1-1 lists primary containment isolation instrumentation that are required to function, in combination with other accident mitigation features, to limit fission product release during and following postulated Design Basis Accidents to within limits. Therefore, TS Table 3.3.6.1-1 must be included in LSCS TS in accordance with 10 CFR 50.36(c)(2)(ii)(c).
Paragraph (h)(2) of 10 CFR 50.55a, "Codes and Standards," states, in part, that for protection and safety systems at nuclear power plants with construction permits issued between January 1, 1971 and May 13, 1999, protection systems must satisfy the requirements stated in either IEEE Std. 279, "Criteria for Protection Systems for Nuclear Power Generating Stations,"
or in IEEE Std. 603-1991, "Criteria for Safety Systems for Nuclear Power Generating Stations."
IEEE Std. 279-1971 is referenced in Chapter 7, "Instrumentation and Control Systems, " of the LSCS Updated Final Safety Analysis Report (UFSAR). UFSAR Table 7.1-4 (Reference 6.6) indicates that MSL High Flow Function for Containment and Reactor Vessel Isolation Control System meets the requirements of IEEE Std. 279-1971. The replacement transmitters and trip units have been confirmed to satisfy the requirements of IEEE Std. 279-1971.
The NRC's guidance for the format and content of LSCS TSs is found in NUREG-1434 (Reference 6.1).
The proposed TS change to Table 3.3.6.1-1 is consistent with the current regulations.
4.2 Precedent The activities proposed in this TS change are the same as the implementation of Channel Check requirements for the modification of equipment in previously-approved Amendment Nos.
166 and 152 for LaSalle. (Reference 6.4) Also, Columbia Generating Station amended TS to add a Channel Check surveillance requirement to TS 3.3.6.1, including Table 3.3.6.1-1 for new equipment supporting the performance of a Channel Check. (Reference 6.5)
ATTACHMENT 1 Request for Amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" 3
4.3 No Significant Hazards Consideration Constellation Energy Generation, LLC (CEG) requests the amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation."
CEG has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:
- 1.
Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed change to Technical Specification (TS) Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" will incorporate into the LaSalle County Station (LSCS) TS, wording specified in NUREG -1434 (Reference 6.1). The proposed change will modify TS Table 3.3.6.1-1 to add the requirement to perform a Channel Check in accordance with Surveillance Requirement (SR) 3.3.6.1.1 for only the Main Steam Line FlowHigh instrument Function. The performance of TS surveillance testing is not a precursor to any accident previously evaluated. A Channel Check is a monitoring activity that does not represent an accident initiator. Thus, the proposed change does not have any effect on the probability of an accident previously evaluated.
The function of the instrumentation listed on TS Table 3.3.6.1-1, in combination with other accident mitigation features, is to limit fission product release during and following postulated Design Basis Accidents (DBAs) to within limits. The surveillance testing specified in TS Table 3.3.6.1-1 increases assurance that the instrumentation will perform as designed. Thus, the radiological consequences of any accident previously evaluated are not increased.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2.
Does the proposed change create the possibility of a new or different kind of accident from any previously evaluated?
Response: No The proposed change does not affect the control parameters governing unit operation or the response of plant equipment to transient conditions. The failure modes of the new instrumentation do not give rise to a new or different kind of accident. The proposed change does not introduce any new modes of system operation or failure mechanisms.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
ATTACHMENT 1 Request for Amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" 4
- 3.
Does the proposed change involve a significant reduction in a margin of safety?
Response: No The Main Steam Line FlowHigh detection system at LSCS uses differential pressure switches that are connected to a flow element on each of the four MSLs, allowing detection of a MSL break and initiating closure of the MSIVs. The current flow switches do not have the capability to allow a Channel Check to be performed. Thus, the LSCS TS took exception to the guidance contained in NUREG-1434 (Reference 6.1) and did not specify on TS Table 3.3.6.1-1 that a SR 3.3.6.1.1 CHANNEL CHECK be performed on the instrument function.
The replacement differential pressure transmitters provide signals to trip units that contain analog displays that permit the performance of a Channel Check with the Unit in MODES 1, 2 and 3. The replacement transmitters and trip units are scheduled to be installed on Unit 1 during the February 2026 refuel outage and are scheduled to be installed in Unit 2 during the February 2027 refuel outage.
LSCS is requesting that TS Table 3.3.6.1-1 is modified to specify that a SR 3.3.6.1.1 CHANNEL CHECK be performed in MODES 1, 2 and 3 for Function 1.c, consistent with the guidance contained in NUREG-1434 (Reference 6.1).
Therefore, the proposed changes do not involve a significant reduction in a margin of safety.
Based on the above, CEG concludes that the proposed amendment presents no significant hazards considerations under the standards set forth in 10 CFR 50.92(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 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.
5.0 ENVIRONMENTAL CONSIDERATION
The proposed amendment would add a Channel Check surveillance requirement on new plant equipment that is capable of performance of a Channel Check. The proposed amendment 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 amendments 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 amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, in
ATTACHMENT 1 Request for Amendment to Technical Specifications Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation" 5
accordance with 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.
6.0 REFERENCES
6.1 NUREG-1434, Revision 5, "Standard Technical Specifications, General Electric Plants, BWR/6," dated September, 2021 (ADAMS Accession No. ML21271A582) 6.2 Information Notice 88-51, Office of Nuclear Reactor Regulation, dated July 21, 1988 (ADAMS Accession No. ML031150112) 6.3 Letter from A. Schwencer (NRC) to Dennis L. Farrar (Commonwealth Edison), "Issuance of Amendment No. 22 to Facility Operating License No. NPF-11 and Amendment No. 10 to Facility Operating License No. NPF La Salle County Station, Units 1 and 2,"
dated April 30, 1985 (ADAMS Accession No. ML02112077) 6.4 Letter from William A. Macon, Jr. (NRC) to Christopher M. Crane (Exelon Nuclear),
"LaSalle County Station, Units 1 and 2, Issuance of Amendments RE: Primary Containment Isolation Instrumentation" dated March 5, 2004 (ADAMS Accession No. ML040690451) 6.5 Letter from Carl F. Lyon (NRC) to Mark E. Reddeman (Energy Northwest), Columbia Generating Station - Issuance of Amendment Re "Add Channel Check Surveillance Requirement to Technical Specification 3.3.6.1" dated November 3, 2010 (ADAMS Accession No. ML102280473) 6.6 LaSalle County Station Final Safety Analysis Report, Revision 26
- a. Section 7.3.2.2.3.4, Primary Containment and Reactor Vessel Isolation Control Instrumentation and Control - Main Steamline High Flow
- b. Table 7.1-4, Containment and Reactor Vessel Isolation Control System Codes and Standards
ATTACHMENT 2 Marked up Technical Specifications Page Proposed for Amendment LaSalle County Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374 Markup of Technical Specifications Page 3.3.6.1-6
Primary Containment Isolation Instrumentation 3.3.6.1 LaSalle 1 and 2 3.3.6.1-6 Amendment No.169/155 Table 3.3.6.1-1 (page 1 of 4)
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 LevelLow Low Low, Level 1 1,2,3 2
D SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.4 SR 3.3.6.1.5
-137.0 inches b.
Main Steam Line PressureLow 1
2 E
SR 3.3.6.1.2 SR 3.3.6.1.3 SR 3.3.6.1.5 826.5 psig c.
Main Steam Line FlowHigh 1,2,3 2 per MSL D
SR 3.3.6.1.2 SR 3.3.6.1.3 SR 3.3.6.1.5 SR 3.3.6.1.6 128.0 psid d.
Condenser VacuumLow 1,2(a),
3(a) 2 D
SR 3.3.6.1.2 SR 3.3.6.1.4 SR 3.3.6.1.5 3.8 inches Hg vacuum e.
Main Steam Line Tunnel Differential TemperatureHigh 1,2,3 2
D SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.4 SR 3.3.6.1.5 66.4F f.
Manual Initiation 1,2,3 2
G SR 3.3.6.1.5 NA 2.
Primary Containment Isolation a.
Reactor Vessel Water LevelLow Low, Level 2 1,2,3 2
H SR 3.3.6.1.2 SR 3.3.6.1.4 SR 3.3.6.1.5
-58.0 inches b.
Drywell PressureHigh 1,2,3 2
H SR 3.3.6.1.2 SR 3.3.6.1.4 SR 3.3.6.1.5 1.93 psig c.
Reactor Building Ventilation Exhaust Plenum RadiationHigh 1,2,3 2
F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.4 SR 3.3.6.1.5 42.0 mR/hr d.
Fuel Pool Ventilation Exhaust RadiationHigh 1,2,3 2
F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.4 SR 3.3.6.1.5 42.0 mR/hr (continued)
(a)
With any turbine stop valve not closed.
SR 3.3.6.1.1(b)
(b) For FUNCTION 1.c, SR 3.3.6.1.1 will commence for Unit 1 with entrance into MODE 2 during L1R21, with the SR to commence for Unit 2 with entrance into MODE 2 during L2R21.