ML23212B105

Supplement to License Amendment Request to Revise Technical Specifications and Exemption Request from Requirements of 10CFR50.62 ATWS Rule to Support the Digital Modernization Project Installation - Revise

ML23212B105
Person / Time
Site:	Limerick
Issue date:	07/31/2023
From:	David Helker Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML23212B105 (1)

Text

200 Exelon Way Kennett Square, PA 19348 www.ConstellationEnergy.com 10 CFR 50.90 July 31, 2023 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTN: Document Control Desk 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:

Supplement to License Amendment Request to Revise Technical Specifications and Exemption Request from Requirements of 10CFR50.62 ATWS Rule to Support the Digital Modernization Project Installation - Revise Unit 1 Technical Specifications

References:

1. Constellation Energy Generation, LLC (CEG) letter to the U.S. Nuclear Regulatory Commission (NRC), "License Amendment Request to Revise the Licensing and Design Basis to Incorporate the Replacement of Existing Safety-Related Analog Control Systems with a Single Digital Plant Protection System (PPS)," dated September 26, 2022 (NRC Agencywide Documents Access and Management System (ADAMS) Accession No. ML22269A5690).

2. Constellation Energy Generation, LLC (CEG) letter to the U.S. Nuclear Regulatory Commission (NRC), License Amendment Request to Revise Technical Specifications and Exemption Request from Requirements of 10CFR50.62 ATWS Rule to Support the Digital Modernization Project Installation," dated February 17, 2023 (ADAMS Accession No. ML23048A313).

3. Constellation Energy Generation, LLC letter to U.S. Nuclear Regulatory Commission, Supplement to License Amendment Request to Revise the Licensing and Design Basis to Incorporate the Replacement of Existing Safety-Related Analog Control Systems with a Single Digital Plant Protection System (PPS)-Pivot to Unit 2 First Installation, dated May 23, 2023 (ADAMS Accession No. ML23143A342).

Per Reference 1, and in accordance with 10 CFR 50.90, Constellation Energy Generation, LLC (CEG) requested amendments to Renewed Facility Operating License Nos. NPF-39 and NPF-85 for Limerick Generating Station (LGS), Units 1 and 2, respectively. The proposed changes would revise the LGS licensing and design basis to incorporate a planned digital modification at LGS (i.e., the LGS Digital Modernization Project).

Supplement to Installation Support LAR for DMP Docket Nos. 50-352 and 50-353 July 31, 2023 Page 2 Per Reference 2, and in accordance with 10 CFR 50.90, Constellation Energy Generation, LLC (CEG) requested an amendment to Appendix A, "Technical Specifications" (TS) of Renewed Facility Operating License Nos. NPF-39 and NPF-85 for Limerick Generating Station (LGS), Units 1 and 2, respectively. Reference 2 also contained an Exemption Request from requirements of 10CFR50.62 ATWS Rule. The proposed changes will revise the LGS Technical Specifications (TS) to adopt features from NUREG-1433, Revision 5, "Standard Technical Specifications for General Electric BWR/4 Plants." The proposed changes will support the installation of the new Plant Protection System (PPS) described in Reference 1.

Per Reference 3, CEG notified NRC that the final design activities for the PPS have been delayed due to additional design refinement iterations with the system Original Equipment Manufacturer. CEG had concluded that it was no longer possible to have the design completed and equipment ready in time to support the Unit 1 installation during the April 2024 Refueling Outage. CEG had decided to pivot final design and project activities to support the first installation of the PPS on Unit 2 during its planned April 2025 Refueling Outage.

Accordingly, the Unit 1 marked-up Technical Specifications (TSs) in Reference 3 that contain references to the 2024 Refueling Outage need to be revised to reflect the Unit 1 installation occurring during its Spring 2026 Refueling Outage. CEG considers this a minor administrative change and the reason for the changes are necessary to align with the current project installation schedule for Unit 1. Therefore, an evaluation of the proposed TS changes is not warranted. Unit 2 TS markups, as proposed in Reference 2, are unaffected.

Unit 1 TS page 3/4 1-20 is being revised to reflect that, in SR 4.1.5.b.4 Note ***, refueling outage is changing from 2024 to 2026 as follows:

For a period of 30 days preceding exit of OPERATIONAL CONDITION 1 at the start of the 2026 refueling outage, no pumps are required to start automatically.

Unit 1 TS page 3/4 3-17 is being revised to reflect that, in Table 3.3.2-1 Reactor Water Cleanup System Isolation Trip Function 3.d on SLCS Initiation Note (h), refueling outage is changing from 2024 to 2026 as follows:

For a period of 30 days preceding exit of OPERATIONAL CONDITION 1 at the start of the 2026 refueling outage, the Reactor Water Cleanup System Isolation on SLCS Initiation Trip Function is not required to be OPERABLE.

Unit 1 TS page 3/4 3-31 is being revised to reflect that, in Table 4.3.2.1-1 Reactor Water Cleanup System Isolation Trip Function 3.d on SLCS Initiation Note (b), refueling outage is changing from 2024 to 2026 as follows:

For a period of 30 days preceding exit of OPERATIONAL CONDITION 1 at the start of the 2026 refueling outage, the Reactor Water Cleanup System Isolation on SLCS Initiation Trip Function is not required to be OPERABLE.

Supplement to Installation Support LAR for DMP Docket Nos. 50-352 and 50-353 July 31, 2023 Page 3 Unit 1 TS page 3/4 3-42 is being revised to reflect that, in LCO 3.3.4.1 for ATWS Recirculation Pump Trip System Instrumentation Applicability Note (Insert 1), the refueling outage is changing from 2024 to 2026 as follows:

For a period of 30 days preceding exit of OPERATIONAL CONDITION 1 at the start of the 2026 refueling outage, the LCO is not applicable when the following conditions are met:

The Attachment to this letter contains only the revised markups of the affected TS pages provided in Reference 2.

CEG has reviewed the information supporting a finding of no significant hazards consideration, and the environmental consideration, which was previously provided to the NRC in the Reference 2 letter. CEG has concluded that the information provided in this supplemental letter does not affect the bases for concluding that the proposed license amendments do not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92. In addition, CEG has concluded that the information in this supplemental letter does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendments.

This supplemental letter contains no regulatory commitments.

In accordance with 10 CFR 50.91, "Notice for public comment; State consultation,"

paragraph (b), CEG is notifying the Commonwealth of Pennsylvania of this license amendment request supplement by transmitting a copy of this letter to the designated State Official.

If you have any questions regarding this submittal, then please contact Frank Mascitelli at Francis.Mascitelli@constellation.com.

I declare under penalty of perjury that the foregoing is true and correct. Executed on this 31st day of July 2023.

Respectfully, David P. Helker Sr. Manager - Licensing Constellation Energy Generation, LLC

Attachment:

Technical Specification Page Markups cc: USNRC Region I, Regional Administrator w/ attachment

Supplement to Installation Support LAR for DMP Docket Nos. 50-352 and 50-353 July 31, 2023 Page 4 USNRC Project Manager, LGS "

USNRC Senior Resident Inspector, LGS "

Director, Bureau of Radiation Protection - Pennsylvania Department "

of Environmental Protection

Attachment License Amendment Request Limerick Generating Station, Units 1 and 2 Docket Nos. 50-352 and 50-353 Technical Specification Page Markups TS Pages, Unit 1 3/4 1-20 3/4 3-17 3/4 3-31 3/4 3-42

REACTIVITY CONTROL SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

b. In accordance with the Surveillance Frequency Control Program by:

1. Verifying the continuity of the explosive charge.

2. Determining by chemical analysis and calculation* that the available weight of Boron-10 is greater than or equal to 185 lbs; the concentration of sodium pentaborate in solution is less than or equal to 13.8% and within the limits of Figure 3.1.5-1 and; the following equation is satisfied:

C x E x Q 1 13% wt. 29 atom % 86 gpm where C = Sodium pentaborate solution (% by weight)

Q = Two pump flowrate, as determined per surveillance requirement 4.1.5.c.

E = Boron 10 enrichment (atom % Boron 10)

3. Verifying that each valve (manual, power-operated, or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position.

4. Verifying that no more than two pumps are aligned for automatic operation.***

c. Demonstrating that, when tested pursuant to Specification 4.0.5, the minimum flow requirement of 37.0 gpm per pump at a pressure of greater than or equal to 1230 25 psig is met.

d. In accordance with the Surveillance Frequency Control Program by:

1. Initiating at least one of the standby liquid control system loops, including an explosive valve, and verifying that a flow path from the pumps to the reactor pressure vessel is available by pumping demineralized water into the reactor vessel. The replacement charge for the explosive valve shall be from the same manufactured batch as the one fired or from another batch which has been certified by having one of the batch success-fully fired. All injection loops shall be tested in 3 operating cycles.

2. Verify all heat-treated piping between storage tank and pump suction is unblocked.**

e. Prior to addition of Boron to storage tank verify sodium pentaborate enrichment to be added is 49 atom % Boron 10.

• This test shall also be performed anytime water or boron is added to the solu-tion or when the solution temperature drops below the limits of Figure 3.1.5-1 for the most recent concentration analysis, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after water or boron addition or solution temperature is restored.

• • This test shall also be performed whenever suction piping temperature drops below the limits of Figure 3.1.5-1 for the most recent concentration analysis, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after solution temperature is restored.

• • • For a period of 30 days preceding exit of OPERATIONAL CONDITION 1 at the start of the 2026 refueling outage, no pumps are required to start automatically.

LIMERICK - UNIT 1 3/4 1-20 Amendment No. 59,61,66,91,106,185, 186, 201, 232

TABLE 3.3.2-1 (Continued)

TABLE NOTATIONS (c) Actuates secondary containment isolation valve. Signals B, H, S, and R also start the standby gas treatment system.

(d) RWCU system inlet outboard isolation valve closes on SLCS "B" initiation.

RWCU system inlet inboard isolation valve closes on SLCS "A" or SLCS "C" initiation.

(e) Manual initiation isolates the steam supply line outboard isolation valve and only following manual or automatic initiation of the system.

(f) In the event of a loss of ventilation the temperature - high setpoint may be raised by 50F for a period not to exceed 30 minutes to permit restoration of the ventilation flow without a spurious trip. During the 30 minute period, an operator, or other qualified member of the technical staff, shall observe the temperature indications continuously, so that, in the event of rapid increases in temperature, the main steam lines shall be manually isolated.

(g) Wide range accident monitor per Specification 3.3.7.5.

(h) For a period of 30 days preceding exit of OPERATIONAL CONDITION 1 at the start of the 2026 refueling outage, the Reactor Water Cleanup System Isolation on SLCS Initiation Trip Function is not required to be OPERABLE.

LIMERICK - UNIT 1 3/4 3-17 Amendment No. 28, 53, 112, 146

TABLE 4.3.2.1-1 (Continued)

ISOLATION ACTUATION INSTRUMENTATION SURVEILLANCE REQUIREMENTS CHANNEL OPERATIONAL CHANNEL FUNCTIONAL CHANNEL CONDITIONS FOR WHICH TRIP FUNCTION CHECK (a) TEST (a) CALIBRATION(a) SURVEILLANCE REQUIRED

7. SECONDARY CONTAINMENT ISOLATION

a. Reactor Vessel Water Level Low, Low - Level 2 1, 2, 3

b. Drywell Pressure## - High 1, 2, 3 c.1. Refueling Area Unit 1 Ventilation Exhaust Duct Radiation - High *#

2. Refueling Area Unit 2 Ventilation Exhaust Duct Radiation - High *#

d. Reactor Enclosure Ventilation Exhaust Duct Radiation - High 1, 2, 3

e. Deleted

f. Deleted

g. Reactor Enclosure Manual Initiation N.A. N.A. 1, 2, 3

h. Refueling Area Manual Initiation N.A. N.A. *

(a) Frequencies are specified in the Surveillance Frequency Control Program unless otherwise noted in the table.

• Required when handling RECENTLY IRRADIATED FUEL in the secondary containment.

• • When not administratively bypassed and/or when any turbine stop valve is open.

1. During operation of the associated Unit 1 or Unit 2 ventilation exhaust system.

1. 1. These trip functions (2a, 6b, and 7b) are common to the RPS actuation trip function.

LIMERICK - UNIT 1 3/4 3-31 Amendment No. 23, 40, 53, 69, 89, 112, 185, 186, 227 (b) For a period of 30 days preceding exit of OPERATIONAL CONDITION 1 at the start of the 2026 refueling outage, the Reactor Water Cleanup System Isolation on SLCS Initiation Trip Function is not required to be OPERABLE.

INSTRUMENTATION 3/4.3.4 RECIRCULATION PUMP TRIP ACTUATION INSTRUMENTATION ATWS RECIRCULATION PUMP TRIP SYSTEM INSTRUMENTATION LIMITING CONDITION FOR OPERATION 3.3.4.1 The anticipated transient without scram recirculation pump trip (ATWS-RPT) system instrumentation channels shown in Table 3.3.4.1-1 shall be OPERABLE with their trip setpoints set consistent with values shown in the Trip Setpoint column of Table 3.3.4.1-2.

APPLICABILITY: OPERATIONAL CONDITION 1.

Insert 1 ACTION:

a. With an ATWS recirculation pump trip system instrumentation channel trip setpoint less conservative than the value shown in the Allowable Values column of Table 3.3.4.1-2, declare the channel inoperable until the channel is restored to OPERABLE status with the channel trip setpoint adjusted consistent with the Trip Setpoint value.

b. With the number of OPERABLE channels one less than required by the Minimum OPERABLE Channels per Trip System requirement for one or both trip systems, place the inoperable channel(s) in the tripped condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or in accordance with the Risk Informed Completion Time Program*.

c. With the number of OPERABLE channels two or more less than required by the Minimum OPERABLE Channels per Trip System requirement for one trip system and:

1. If the inoperable channels consist of one reactor vessel water level channel and one reactor vessel pressure channel, place both inoperable channels in the tripped condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or in accordance with the Risk Informed Completion Time Program, or if this action will initiate a pump trip, declare the trip system inoperable.

2. If the inoperable channels include two reactor vessel water level channels or two reactor vessel pressure channels, declare the trip system inoperable.

d. With one trip system inoperable, restore the inoperable trip system to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or in accordance with the Risk Informed Completion Time Program, or be in at least STARTUP within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

e. With both trip systems inoperable, restore at least one trip system to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or be in at least STARTUP within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.3.4.1.1 Each of the required ATWS recirculation pump trip system instrumentation channels shall be demonstrated OPERABLE by the performance of the CHANNEL CHECK, CHANNEL FUNCTIONAL TEST and CHANNEL CALIBRATION operations at the frequencies specified in the Surveillance Frequency Control Program.

4.3.4.1.2 LOGIC SYSTEM FUNCTIONAL TESTS and simulated automatic operation of all channels shall be performed in accordance with the Surveillance Frequency Control Program.

• Not applicable when trip capability is not maintained.

LIMERICK - UNIT 1 3/4 3-42 Amendment No. 70,71,186, 240

Insert 1 Note: For a period of 30 days preceding exit of OPERATIONAL CONDITION 1 at the start of the 2026 refueling outage, the LCO is not applicable when the following conditions are met:

Maximum Maximum Inoperable Minimum Suppression THERMAL POWER Safety/Relief Valves Pool Water Level 90% RTP 0 of 14 23 feet 87% RTP 0 of 14 22 feet 84% RTP 1 of 14 22 feet Recirc Runback on Level 3 Function is Available and not in Bypass.