ML23292A074
| ML23292A074 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 10/19/2023 |
| From: | David Helker Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| Download: ML23292A074 (1) | |
Text
200 Exelon Way Kennett Square, PA 19348 www.ConstellationEnergy.com 10 CFR 50.90 October 19, 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:
Response to Request for Additional Information (RAI-14) for Supplemental License Amendment Request to Revise Technical Specifications and Exemption Request from Requirements of 10CFR50.62 ATWS Rule to Support the Digital Modernization Project Installation
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 letter to U.S. Nuclear Regulatory Commission, 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. ML23052A022) 3.
Email from Nick Smith, U.S. Nuclear Regulatory Commission to Francis Mascitelli, Constellation Energy Generation, LLC, RAIs for Limerick Generation Station, Units 1 and 2 - LAR and Exemption Request for Digital I&C Installation Support (EPID L-2023-LLA-0025 and L-2023-LLE-0005),
dated June 20, 2023 (ADAMS Accession No. ML23173A063) 4.
Constellation Energy Generation, LLC letter to U.S. Nuclear Regulatory Commission, Response to Request for Additional Information for Supplemental 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 July 21, 2023 (ADAMS Accession ML23202A219)
DMP Installation Support LAR RAI Response Docket Nos. 50-352 and 50-353 October 19, 2023 Page 2 5.
Email from Nick Smith, U.S. Nuclear Regulatory Commission to Francis Mascitelli, Constellation Energy Generation, LLC, RAIs for Limerick Generation Station, Units 1 and 2 - LAR and Exemption Request for Digital I&C Installation Support (EPID L-2023-LLA-0025 and L-2023-LLE-0005),
dated July 26, 2023 (ADAMS Accession No. ML23201A126)
- 6. Constellation Energy Generation, LLC letter to U.S. Nuclear Regulatory Commission, Response to Request for Additional Information for Supplemental 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 September 16, 2023 (ADAMS Accession No. 23228A094)
- 7. Meeting with Constellation Energy Generation, LLC Regarding Installation Support License Amendment Request for Limerick Generating Station, Units 1 and 2, dated September 21, 2023 (ADAMS Accession No. ML23251A03)
In accordance with 10 CFR 50.90, Constellation Energy Generation, LLC (CEG) requested a License Amendment Request (LAR) to replace the Limerick Generating Station, Units 1 and 2 existing safety-related analog control systems with a single digital Plant Protection System (PPS) (Reference 1).
In Reference 2, CEG submitted an Installation Support LAR to facilitate the installation of the new PPS described in Reference 1.
In Reference 3, by email dated June 20, 2023, the NRC notified CEG that additional information was needed to complete its review of the Reference 2 submittal. In Reference 4, CEG responded to the Reference 3 Request for Additional Information (RAI).
In Reference 5, NRC identified further RAIs to facilitate their continuing review. In Reference 6, CEG responded to Reference 5 RAI.
In a subsequent public meeting (Reference 7), NRC requested a follow-up clarification to RAI #14 response contained in Reference 6. to this letter provides the response to public meeting request for additional clarification to RAI-14. contains the proposed revised TS Markups that reflect the follow-up response to RAI-14.
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 RAI response 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
DMP Installation Support LAR RAI Response Docket Nos. 50-352 and 50-353 October 19, 2023 Page 3 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 supplemental letter 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 267-533-5677 or Ashley Rickey at 267-533-1427.
I declare under penalty of perjury that the foregoing is true and correct. Executed on this 19th day of October 2023.
Respectfully, David P. Helker Sr. Manager - Licensing Constellation Energy Generation, LLC Response to Request for Additional Information (RAI-14) for Supplemental License Amendment Request to Revise Technical Specifications and Exemption Request from Requirements of 10CFR50.62 ATWS Rule to Support the Digital Modernization Project Installation Proposed Revised TS Markups for TS 3.9.1 cc:
USNRC Region I, Regional Administrator w/ attachments USNRC Project Manager, LGS USNRC Senior Resident Inspector, LGS Director, Bureau of Radiation Protection - Pennsylvania Department of Environmental Protection License Amendment Request Supplement Limerick Generating Station, Units 1 and 2 Docket Nos. 50-352 and 50-353 Response to Request for Additional Information (RAI-14) for Supplemental License Amendment Request to Revise Technical Specifications and Exemption Request from Requirements of 10CFR50.62 ATWS Rule to Support the Digital Modernization Project Installation Page 1 DMP Installation Support LAR RAI-14 Response Docket Nos. 50-352 and 50-353 October 19, 2023 NRC staff had reviewed the RAI-14 response provided in Reference 6 and requested a follow-up public meeting on September 21, 2023, to clarify the CEG response and basis regarding the proposed Technical Specification 3.9.1, Action b, to delete the option of locking the reactor mode switch in the Shutdown mode position. NRC questioned the basis for not having an additional TS action to be taken when the one-rod-out interlock is inoperable and it could not be verified that all control rods are fully inserted and the rod withdraw capabilities are disabled.
Below is the revised supplemental response to address NRC staff concerns with RAI-14 CEG Response:
CEG Supplemental Response to RAI-14:
CEG has reviewed the original response to RAI-14 contained in Reference 6. CEG agrees with NRC that TS 3.9.1 Action b, is ambiguous and should be clarified. CEG interprets "verify all control rods are fully inserted" to require verification or action to fully insert all control rods. For clarity, CEG has decided to reword the Limerick TS to require fully inserting all control rods, thereby making the action explicit instead of implied.
Accordingly, Attachment 2 contains the revised TS markups that reflect the NUREG STS 3.9.2 requirements.
In addition, TS 3.9.1 Actions c.1 and d.1 are also revised to be consistent with the proposed revised Action b wording to fully insert all control rods.
Note: the other proposed changes on TS page 3/4 9-1 (LCO 3.9.1, Applicability and Action a) in the License Amendment Request (Reference 2) remain unaffected.
Requested NRC Clarification Regarding RAI-14
License Amendment Request Supplement Limerick Generating Station, Units 1 and 2 Docket Nos. 50-352 and 50-353 Proposed Revised TS Markups for TS 3.9.1 TS page 3/4 9-1 Unit 1 TS page 3/4 9-1 Unit 2
'\\_J 3.4.9 REFUELING OPERATIONS 3/4.9.1 REACTOR MODE SWITCH l.IM.IIJtlli,J:DNDnl_OJL.EOR OITMI.I.O.N=============
3.9.1 The reactor mode switch shall be OPERABLE and locked in the Shutdown or Refuel position. When the reactor mode switch is locked in the Refuel position:
a.
The Refuel position one-rod-out interlock shall be OPERABLE.
b.
The following Refuel position interlocks shall be OPERABLE:
- 1. A 11 rods in.
- 2. Refuel Platform (over-core) position.
- 3. Refuel Platform hoists fuel-loaded.
- 4. Service Platform hoist fuel-loaded (with Service Platform installed).
APPLICABILITY: OPERATIONAL CONDITION 5* **, OPERATIONAL CONDITIONS 3 ANO 4 when the reactor mode switch is in the Refuel position.
ACTION:
a.
With the reactor mode switch not locked in the Shutdown or Refuel position as specified, suspend CORE ALTERATIONS and lock the reactor mode switch in the Shutdown or Refuel position.
b.
With the one-rod-out interlock inoperable, verify all control rods are fully inserted and disable withdraw capabilities of all control rods ***,
or lock the reactor mode switch in the Shutdown position.
c.
With any of the above required Refuel Platform Refuel position interlocks inoperable, take one of the ACTIONS listed below, or suspend CORE ALTERATIONS.
1.
Verify control rods are fully inserted and disable withdraw capabilities of all control rods***, or 2.
Verify Refuel Platform is not over-core (limit switches not reached) and disable Refuel Platform travel over-core, or 3.
Verify that no Refuel Platform hoist is 1 oaded and di sab 1 e a 11 Refuel Platform hoists from picking up (grappling) a load.
d.
With the Service Platform installed over the vessel and any of the above required Service Platform Refuel position interlocks inoperable, take one of the ACTIONS listed below, or suspend CORE ALTERATIONS.
- 1.
Verify all control rods are fully inserted and disable withdraw capabilities of all control rods***, or 2.
Verify Service Platform hoist is not loaded and disable Service Platform hoist from picking up (grappling) a load.
See Special Test Exceptions 3.10.1 and 3.10.3.
The reactor shall be maintained in OPERATIONAL CONDITION 5 whenever fuel is in the reactor vessel with the vessel head closure bolts less than fully tensioned or with the head removed.
\\..._/***
Except control rods removed per Specification 3.9.10.1 or 3.9.10.2.
LIMERICK - UNIT 1 3/4 9-1 Amendment No. --tK 149 APR O 5 2oa1 fully insert all control rods Fully insert all control rods Fully insert all control rods
3.4.9 REFUELING OPERATIONS 3/4.9.1 REACTOR MODE SWITCH LIMITING CONDITION FOR OPERATION 3.9.1 The reactor mode switch shall be OPERABLE and locked in the Shutdown or Refuel position. When the reactor mode switch is locked in the Refuel position:
- a.
The Refuel position one-rod-out interlock shall be OPERABLE.
- b.
The following Refuel position interlocks shall be OPERABLE:
- 1. All rods in.
- 2. Refuel Platform (over-core) position.
- 3. Refuel Platform hoists fuel-loaded.
- 4. Service Platform hoist fuel-loaded (with Service Platform installed).
APPLICABILITY: OPERATIONAL CONDITION 5* **, OPERATIONAL CONDITIONS 3 AND 4 when the reactor mode switch is in the Refuel position.
ACTION:
- a.
With the reactor mode switch not locked in the Shutdown or Refuel position as specified, suspend CORE ALTERATIONS and lock the reactor mode switch in the Shutdown or Refuel position.
- b.
With the one-rod-out interlock inoperable, verify all control rods are fully inserted and disable withdraw capabilities of all control rods ***,
or lock the reactor mode switch in the Shutdown position.
- c.
With any of the above required Refuel Platform Refuel position interlocks inoperable, take one of the ACTIONS listed below, or suspend CORE ALTERATIONS.
Verify control rods are fully inserted and disable withdraw capabilities of all control rods***, or
- 2.
Verify Refuel Platform is not over-core (limit switches not reached) and disable Refuel Platform travel over-core, or
- 3.
Verify that no Refuel Platform hoist is loaded and disable all Refuel Platform hoists from picking up (grappling) a load.
- d.
With the Service Platform installed over the vessel and any of the above required Service Platform Refuel position interlocks inoperable, take one of the ACTIONS listed below, or suspend CORE ALTERATIONS.
Verify all control rods are fully inserted and disable withdraw capabilities of all control rods***, or
- 2.
Verify Service Platform hoist is not loaded and disable Service Platform hoist from picking up (grappling) a load.
See Special Test Exceptions 3.10.1 and 3.10.3.
The reactor shall be maintained in OPERATIONAL CONDITION 5 whenever fuel is in the reactor vessel with the vessel head closure bolts less than fully tensioned or with the head removed.
Except control rods removed per Specification 3.9.10.1 or 3.9.10.2.
LIMERICK - UNIT 2 3/4 9-1 Amendment No. 76, 112
- 1.
Fully insert all control rods
- 1.
fully insert all control rods Fully insert all control rods