ML25175A343
| ML25175A343 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 06/24/2025 |
| From: | Elwood T Ameren Missouri |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| Shared Package | |
| ML25175A342 | List: |
| References | |
| ULNRC-06956 | |
| Download: ML25175A343 (1) | |
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.t Callaway Plant SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4) 8315 County Road 459 : Steedman, MO 65077 : AmerenMissouri.com
.t to this letter contains sensitive information. Withhold from public disclosure under 10 CFR 2.390(a)(4). Upon removal of Enclosure 2, this letter is uncontrolled.
SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4)
June 24, 2025 ULNRC-06956 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 10 CFR 50.55a Ladies and Gentlemen:
DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.
RENEWED FACILITY OPERATING LICENSE NPF-30 SUPPLEMENT TO REQUEST FOR RELIEF FROM FLAW CHARACTERIZATION AND FLAW REMOVAL REQUIREMENTS OF ASME CODE, SECTION XI - RELIEF REQUEST I5R-02
References:
See page 4 of this letter.
In the Reference 1 letter, pursuant to 10 CFR 50.55a (z)(1), Union Electric Company (Ameren Missouri) requested Nuclear Regulatory Commission (NRC) approval of Relief Request I5R-02 (Reference 2) for the Callaway Plant. The relief request proposes an alternative to the ASME Code requirements of Section XI as applicable to the flaw indications identified at locations associated with four reactor vessel bottom head (RVBH) bottom mounted instrument (BMI) nozzles. As described in References 1 and 2, during the current refueling outage at the Callaway plant (i.e., RF27), under-vessel and subsequent, additional non-destructive examinations led to the identification of flaw indications at the locations of RVBH BMI Nozzles 30, 35, 48, and 57. A half-nozzle repair and a flaw evaluation are the proposed alternatives to the flaw characterization requirements of IWA-3300 and IWB-3420 and to the flaw removal requirements of IWA-4412 for RVBH BMI Nozzles 30, 35, 48, and 57.
Additional enclosures were provided with the Reference 1 letter. Reference 3 collectively provides the supporting analyses for the Reference 2 relief request, which consist of three, separate, proprietary
ULNRC-06956 June 11, 2025 Page 2 of 6 SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4)
SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4) to this letter contains sensitive information. Withhold from public disclosure under 10 CFR 2.390(a)(4). Upon removal of Enclosure 2, this letter is uncontrolled.
documents. Reference 4 contains redacted versions of the supporting analysis documents. Reference 5 provides affidavits for the proprietary documents.
Subsequent to submittal of the Reference 1 letter and its enclosures, the NRC began their review of the submittal, and from their review, one item of concern was identified that requires resolution.
Resolution of this concern is the basis for this follow-up letter, which is being provided as a supplement to the Reference 1 letter. The concern is that the NRC staff reviewers identified information within the Reference 2 relief request that is classified as non-proprietary; however, similar/identical information within the Reference 3 analysis documents is classified as proprietary.
In response to the NRC's concern, Ameren Missouri took action to re-examine the affected documents.
From this reassessment, it was determined that the description of the half-nozzle repair within the Reference 3 analysis documents should be considered non-proprietary. As such, Enclosures 2-4 of this letter have been provided to replace the originally provided documents (References 3-5). At the same time, it was also identified that the not all of the flaw evaluation description within the Reference 2 relief request can be classified as non-proprietary. Therefore, Ameren Missouri has updated Reference 2 to remove any proprietary information, and Enclosure 1 of this letter has been provided to replace the Reference 2 document. In regard to the proprietary information that was disclosed in the Reference 2 document, Ameren Missouri requests that the NRC withdraw Reference 2 from the public domain (ADAMS).
Another purpose for this letter is to close out commitment COMN 50441, originally identified in Reference 1 and now provided in the "List of Commitments" table on page 4 of this letter. As described in References 1 and 2, due to the emergent nature of the half-nozzle repairs for BMI Nozzles 30, 35, 48, and 57, it was anticipated that the analyses provided in References 3 and 4 could require updates if there were half-nozzle repair implementation changes. On June 22, 2025, the half-nozzle repairs for BMI Nozzles 30, 35, 48, and 57 were completed. As anticipated, the Reference 3 and 4 analyses were revised, based, in part, on the completed half-nozzle repairs, and accordingly, the revised documents are provided as Enclosures 2 and 3 to this letter. The submittal of Enclosures 2 and 3 of this letter satisfies (closes out) commitment COMN 50441, as these enclosures are the final updates to the originally provided analyses. Each analysis contained within Enclosures 2 and 3 includes a summary and/or description of changes. The results of the updated analyses continue to justify use of the half-nozzle repair modification for one cycle of operation.
In regard to Ameren Missouri's request for approval of Relief Request I5R-02, verbal approval is desired prior to entry into Mode 4 for restart from Callaway's current refueling outage (RF27). As Mode 4 entry is scheduled at the end of June or beginning of July (2025), verbal approval is respectfully requested on or before June 30, 2025.
ULNRC-06956 June 11, 2025 Page 3 of 6 SENSITIVE INFORMATION -WITHHOLD UNDER 10 CPR 2.390(a)(4)
For any questions concerning this submittal, please contact the undersigned at (314) 225-1905.
This letter contains one commitment which is summarized in the "List of Commitments" table on page 4 of this letter. As noted above, the submittal of Enclosures 2 and 3 satisfy ( close out) this commitment.
/ESS, Relief Request I5R-02, Relief Request I5R-02 Attachments 1, 2, and 3, Non-Proprietary Documents, Affidavits for Proprietary Documents Sincerely, Thomas B. Elwood Regulatory Affairs Manager to this letter contains sensitive information. Withhold from public disclosure under 1 O CFR 2.390(a)(4). Upon removal of Enclosure 2, this letter is uncontrolled.
SENSITIVE INFORMATION-WITHHOLD UNDER 10 CFR 2.390(a)(4)
ULNRC-06956 June 11, 2025 Page 4 of 6 SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4)
SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4) to this letter contains sensitive information. Withhold from public disclosure under 10 CFR 2.390(a)(4). Upon removal of Enclosure 2, this letter is uncontrolled.
References:
- 1. Ameren Missouri letter ULNRC-06948, "Callaway Unit 1, Request for Relief from Flaw Characterization and Flaw Removal Requirements of ASME Code,Section XI - Relief Request I5R-02," dated June 11, 2025 (ADAMS Accession No. ML25163A038)
- 2. Enclosure 1 to Ameren Missouri letter ULNRC-06948, "Relief Request I5R-02," dated June 11, 2025 (ADAMS Accession No. ML25163A039)
- 3. Enclosure 2 to Ameren Missouri letter ULNRC-06948, " Relief Request I5R-02 Attachments 1, 2, and 3," dated June 11, 2025 (ADAMS Accession No. ML25163A040)
- 4. Enclosure 3 to Ameren Missouri letter ULNRC-06948, "Non-Proprietary Documents," dated June 11, 2025 (ADAMS Accession No. ML25163A041)
- 5. Enclosure 4 to Ameren Missouri letter ULNRC-06948, "Affidavits for Proprietary Documents,"
dated June 11, 2025 (ADAMS Accession No. ML25163A042)
LIST OF COMMITMENTS The following table identifies those actions committed to by Ameren Missouri in this document. Any other statements in this document are provided for information purposes and are not considered commitments.
COMMITMENT Due Date/Event COMN Submit, or confirm submittal of, the final revisions of:
- Section III evaluation of modified configuration
- Corrosion evaluation
- One-cycle flaw analytical evaluation Within 14 days following the end of Callaway's current refueling outage (RF27) 50441
ULNRC-06956 June 11, 2025 Page 5 of 6 SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4)
SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4) to this letter contains sensitive information. Withhold from public disclosure under 10 CFR 2.390(a)(4). Upon removal of Enclosure 2, this letter is uncontrolled.
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-06956 June 11, 2025 Page 6 of 6 SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4)
SENSITIVE INFORMATION - WITHHOLD UNDER 10 CFR 2.390(a)(4) to this letter contains sensitive information. Withhold from public disclosure under 10 CFR 2.390(a)(4). Upon removal of Enclosure 2, this letter is uncontrolled.
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)