ML25163A038
| ML25163A038 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 06/11/2025 |
| From: | Elwood T Ameren Missouri, Union Electric Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| Shared Package | |
| ML25163A037 | List: |
| References | |
| ULNRC-06948 | |
| Download: ML25163A038 (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 11, 2025 ULNRC-06948 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 REQUEST FOR RELIEF FROM FLAW CHARACTERIZATION AND FLAW REMOVAL REQUIREMENTS OF ASME CODE, SECTION XI - RELIEF REQUEST I5R-02 References on page 4 of this letter.
Pursuant to 10 CFR 50.55a (z)(1), Union Electric Company (Ameren Missouri) requests Nuclear Regulatory Commission (NRC) approval of the enclosed relief request for the Callaway Plant. The enclosed relief request, identified as Relief Request I5R-02, 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.
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, as described in Relief Request I5R-02, at the locations of RVBH BMI Nozzles 30, 35, 48, and 57. Ameren Missouri is proposing a half-nozzle repair and a flaw evaluation as 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.
The duration of Relief Request I5R-02, which is based on provided analyses, is for one cycle of operation that begins upon completion of the current outage and is scheduled to conclude in the Fall of
ULNRC-06948 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.
2026. The supporting analyses consist of three, separate, proprietary documents collectively provided in Enclosure 2 of this letter. Enclosure 3 contains redacted versions of the supporting analysis documents. Enclosure 4 provides affidavits for the proprietary documents.
Due to the emergent nature of the half-nozzle repairs for BMI Nozzles 30, 35, 48, and 57, updates to the provided analyses may occur if field implementation changes are warranted. Therefore, a commitment has been established to submit the additional information in a timely manner. This commitment is identified in the "List of Commitments" table on page 4 of this letter.
As noted above and in attached Relief Request I5R-02, the relief request and its supporting analyses justify one cycle of operation. A separate relief request will be submitted to justify continued use of the half-nozzle repair beyond one cycle of operation. This follow-up relief request will contain the appropriate analyses and justification in support of operation for the remainder of current plant licensing and will be submitted prior to the end of the upcoming operating cycle.
It should be noted that a separate relief request, Relief Request I5R-01, was previously submitted (with a subsequent revision) in connection with the BMI nozzle repairs. NRC verbal authorization was obtained for both the original and revised version of the relief request. (See References 1-4.) Relief Request I5R-01 allows non-destructive examination (NDE) of the new Alloy 52M weld pad for BMI Nozzles 30, 35, 48, and 57 to be performed without applying the required 48-hour hold time per Code Case N-638-11. Elimination of the 48-hour NDE hold time and the basis for that is not within the scope of Relief Request I5R-02, as Relief Request I5R-01 was submitted solely for that purpose.
Callaway's Inservice Inspection (ISI) Program complies with the 2019 Edition of the ASME Boiler and Pressure Vessel Code (BPVC),Section XI. Callaway's fifth ISI Interval began December 19, 2024, and ends on December 18, 2036, as a result of Callaway moving from a ten-to twelve-year ISI interval as allowed by ASME Code Case N-921.
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 the end of June (2025).
ULNRC-06948 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. Enclosure 1 to Ameren Missouri letter ULNRC-06947, "Relief Request I5R-01," dated May 22, 2025 (ADAMS Accession No. ML25142A387)
- 2. NRR e-mail, "
Subject:
Callaway Plant, Unit 1 - Verbal Authorization of Request for Alternative I5R 48-Hour Non-Destructive Examination Hold - EPID: L-2025-LLR-0054," dated May 23, 2025 (ADAMS Accession No. ML25147A126)
- 3. Enclosure 1 to Ameren Missouri letter ULNRC-06949, "Revision (Supplement) to Request for ASME Code Relief Regarding 48-Hour Hold Time When Performing Repairs Using Ambient Temperature GTAW Temper Bead Method Per ASME Code Case N-638-11 (Relief Request I5R-01)," dated May 28, 2025 (ADAMS Accession No. ML25148A291)
- 4. NRR e-mail, "
Subject:
Callaway Plant, Unit 1 - Second Verbal Authorization of Request for Alternative I5R 48-Hour Non-Destructive Examination Hold - EPID: L-2025-LLR-0054,"
dated May 30, 2025 (ADAMS Accession No. ML25153A581)
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-06948 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-06948 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)