ULNRC-06907, Supplementation Information and Response to Request for Confirmation of Information (RCI) to Resolve Callaway Plant License Renewal Commitments 34 and 35 - Perform Evaluation of Crack Initiation and Propagation of Steam Generator.
| ML24340A121 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 12/05/2024 |
| From: | Elwood T Ameren Missouri |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| Shared Package | |
| ML24340A120 | List: |
| References | |
| ULNRC-06907 | |
| Download: ML24340A121 (1) | |
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.t Callaway Plant 8315 County Road 459 : Steedman, MO 65077 : AmerenMissouri.com
.t December 5, 2024 ULNRC-06907 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Ladies and Gentlemen:
DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.
RENEWED FACILITY OPERATING LICENSE NPF-30 SUPPLEMENTATION INFORMATION AND RESPONSE TO REQUEST FOR CONFIRMATION OF INFORMATION (RCI) TO RESOLVE CALLAWAY PLANT LICENSE RENEWAL COMMITMENTS 34 AND 35 - PERFORM EVALUATION OF CRACK INITIATION AND PROPAGATION IN STEAM GENERATOR DIVIDER PLATE AND TUBE-TO-TUBESHEET WELDS
References:
Provided on Page 3.
By letter dated December 20, 2023, (Reference 1), Ameren Missouri, submitted to the U.S. Nuclear Regulatory Commission (NRC) a response to Commitment Nos. 34 and 35 of the Callaway Plant License Renewal (LR) safety evaluation report (Reference 2). Commitments 34 and 35 are associated with steam generator divider plate and tube-to-tubesheet welds and address concerns regarding 1) potential failure at the divider plate welds to primary head and tubesheet cladding and 2) potential failure of the primary-to-secondary pressure boundary due to primary water stress corrosion cracking (PWSCC) of tube-to-tubesheet welds. To address both commitments, Ameren Missouri selected Option 2: Analysis of the options identified in Appendix A of Reference 2. The December 20, 2023, letter included Enclosure 1, Cracking Assessment for Framatome RSG Channel Head Assembly (Reference 3), which describes the analyses, and Enclosure 2, "Tube to Tubesheet Welding Report" (Reference 4), which confirms the steam generator weld chromium content.
By letter dated May 7, 2024 (Reference 5), the NRC communicated their plans to conduct an audit of the subject analysis and provided an initial list of document requests. On September 11, 2024, the NRC staff issued audit questions (Reference 6). By October 21, 2024, Ameren Missouri provided responses to all audit questions via an electronic portal. Those audit questions and Ameren Missouri's responses to the questions were discussed and clarified in a teleconference conducted with the NRC staff on October 22, 2024.
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WAmeren MISSOURI
ULNRC-06907 December 5, 2024 Page 2 of 5 On November 8, 2024, and as a follow-up to the October 22, 2024 teleconference, the NRC staff transmitted a draft request for confirmation of information (RCI) to Ameren Missouri. A teleconference was held with the NRC staff on November 12, 2024, to discuss the subject RCI. Bye-mail dated November 13, 2024 (Reference 7), the NRC transmitted the final RCI to Ameren Missouri who agreed to provide a response on the docket prior to December 6, 2024. Accordingly, the purpose of this letter is to provide a response to the RCI and to include supplemental information identified from the October 22, 2024 teleconference. A follow-up letter will also be provided, at a later date, to submit updated Framatome reports as discussed in the attachment to this letter.
This letter does not contain new commitments. If there are any questions, please contact Thomas Elwood at 314-225-1905.
Sincerely, Thomas B. Elwood Manager, Regulatory Affairs ESS
Attachment:
Supplemental Information and Response to Request for Confirmation of Information (RCI) for Resolution of Callaway Plant License Renewal Commitments 34 and 35
ULNRC-06907 December 5, 2024 Page 3 of 5
References:
- 1. Ameren Missouri letter ULNRC-06849, "Callaway, Unit 1, License Renewal Resolution For Commitment 34 and 35 - Perform Evaluation of Crack Initiation and propagation in Steam Generator Divider Plate and Tube-To-Tubesheet Welds," dated December 20, 2023 (ADAMS Accession No. ML23354A245)
- 2. NUREG-2172, "Safety Evaluation Report Related to the License Renewal of Callaway Plant, Unit 1," dated March 2015 (ADAMS Accession No. ML15068A342)
- 3. Enclosure 1 of Ameren Missouri letter ULNRC-06849, "Callaway, Unit 1, Cracking Assessment for Framatome RSG Channel Head Assembly," dated December 20, 2023 (ADAMS Accession No. ML23354A246)
- 4. Enclosure 2 of Ameren Missouri letter ULNRC-06849, "Callaway, Unit 1, Tube to Tubesheet Welding Report," dated December 20, 2023 (ADAMS Accession No. ML23354A247)
- 5. NRC letter, "Callaway Plant, Unit No. 1 - Audit Plan to Support Review of Steam Generator License Renewal Response to Commitment Nos 34 and 35 (EPID L-2024-LRO-0009)," dated May 7, 2024 (ADAMS Accession No. ML24122A150)
- 6. NRC letter, "Callaway Plant, Unit 1 - Regulatory Audit Questions for License Renewal Commitments 34 and 35 (EPID L-2024-LRO-0009) - Non-Proprietary," dated September 11, 2024 (ADAMS Accession No. ML24247A304)
- 7. NRC e-mail capture,
Subject:
"FINAL - Request for Confirmation of Information - Callaway License Renewal Commitments 34 & 35 - EPID: L-2024-LRO-0009," dated November 13, 2024 (ADAMS Accession No. ML24318C256)
ULNRC-06907 December 5, 2024 Page 4 of 5 cc:
Mr. John Monninger Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. M. Chawla Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop O8B1A Washington, DC 20555-0001
ULNRC-06907 December 5, 2024 Page 5 of 5 Index and send hardcopy to QA File A160.0761 Hardcopy:
Certrec Corporation 6500 West Freeway, Suite 400 Fort Worth, TX 76116 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)
Electronic distribution for the following can be made via Responses and Reports ULNRC Distribution:
F. M. Diya K. C. Scott T. M. Hart J. G. Beck T. A. Witt T. B. Elwood NSRB Secretary STARS Regulatory Affairs Mr. Jay Silberg (Pillsbury Winthrop Shaw Pittman LLP)