ML24340A178
| ML24340A178 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 12/05/2024 |
| From: | Ameren Missouri, Union Electric Co |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML24340A175 | List: |
| References | |
| ULNRC-06902, LDCN 24-0018 | |
| Download: ML24340A178 (1) | |
Text
Enclosure to ULNRC-06902 Page 1 of 3 ENCLOSURE DESCRIPTION AND ASSESSMENT
1.0 DESCRIPTION
Ameren Missouri requests adoption ofTSTF-591, "Revise Risk Informed Completion Time (RICT)
Program," which is an approved change to the Standard Technical Specifications (STS), into the Callaway Plant, Unit 1 Technical Specifications. TSTF-591 revises Technical Specification (TS)
Section 5.5, "Risk Informed Completion Time Program," to reference Regulatory Guide (RG) 1.200, Revision 3, instead of Revision 2, and to make other changes. A new report is added to TS Section 5.6, "Reporting Requirements," to inform the NRC of newly developed methods used to calculate RICTs.
2.0 ASSESSMENT
2.1 Applicability of Safety Evaluation Ameren Missouri has reviewed the safety evaluation for TSTF-591 provided to the Technical Specifications Task Force in a letter dated September 21, 2023. This review included the NRC staffs evaluation, as well as the information provided in TSTF-591. Ameren Missouri has concluded that the justifications presented in TSTF-591 and the safety evaluation prepared by the NRC staff are applicable to Callaway Plant, Unit land justify this amendment for incorporation of the changes to the Callaway Plant TSs.
2.2 Variations Ameren Missouri is proposing the following variations from the TS changes described in TSTF-591 or the applicable parts of the NRC staffs safety evaluation:
The Callaway Plant TSs utilize different numbering than the STS on which TSTF-591 was based. Specifically, the Callaway TSs describe the requirements of the RICT program in TS 5.5.19, and the NRC staffs safety evaluation generically points to TS 5.5.20 of the STS from NUREG 1431, recognizing that numbering differences for the RICT program may exist. Additionally, the TS number for the new Callaway TS reporting requirements would be 5.6.11 rather than 5.6.8 as is shown generically in the NRC staffs safety evaluation for TSTF-591. These differences are administrative and do not affect the applicability of TSTF-591 to the Callaway Plant TS.
3.0 REGULATORY ANALYSIS
3.1 No Significant Hazards Consideration Analysis Ameren Missouri requests adoption of TSTF-591, "Revise Risk Informed Completion Time (RICT)
Program," which is an approved change to the Standard Technical Specifications (STS), into the Callaway Plant, Unit 1 TS. TSTF-591 revises Technical Specification (TS) Section 5.5, "Risk Informed Completion Time Program," to reference Regulatory Guide (RG) 1.200, Revision 3, instead of Revision 2, and to make other changes. A new report is added to TS Section 5.6, "Reporting Requirements," to inform the NRC of newly developed methods used to calculate RICTs.
Enclosure to ULNRC-06902 Page 2 of 3 Ameren Missouri has evaluated if a significant hazards consideration is involved with the proposed amendments by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment,"
as discussed below:
- 1.
Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed change updates the standard for maintaining and updating PRA models used to calculate a RICT from NRC-approved Regulatory Guide 1.200, Revision 2, to NRC-approved Regulatory Guide 1.200, Revision 3. A new report is added to inform the NRC when a newly developed method is used.
The proposed change does not involve a significant increase in the probability of an accident previously evaluated because the change involves no change to the plant or its modes of operation. The proposed change does not increase the consequences of an accident because the design-basis mitigation functions of the affected systems are not changed and the consequences of an accident during the extended Risk Informed Completion Time are no different from those during the existing Completion Time. Also, the submittal of information-only reports has no effect on the initiators or consequences of any accidents previously evaluated.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2.
Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed change updates the standard for maintaining and updating PRA models used to calculate a RICT from NRC-approved Regulatory Guide 1.200, Revision 2, to NRC-approved Regulatory Guide 1.200, Revision 3. A new report is added to inform the NRC when a newly developed method is used.
The proposed change does not change a design function or method of operation of the plant.
The proposed change does not involve a physical alteration of the plant (such that no new or different kind of equipment will be installed).
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3.
Does the proposed amendment involve a significant reduction in a margin of safety?
Response: No
Enclosure to ULNRC-06902 Page 3 of 3 The proposed change updates the standard for maintaining and updating PRA models used to calculate a RICT from NRC-approved Regulatory Guide 1.200, Revision 2, to NRC-approved Regulatory Guide 1.200, Revision 3. A new report is added to inform the NRC when a newly developed method is used.
The proposed change supports the extension of Completion Times provided risk is assessed and managed in accordance with the NRC-approved RICT Program. The proposed change does not alter any design basis or safety limits. The proposed change affects the standard used to maintain the PRA models used in the RICT Program by changing from one NRC-approved standard to a later NRC-approved version and requiring submittal of an information-only report. The RICT Program will continue to assure that adequate margins of safety are maintained.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above, Ameren Missouri concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.
3.2 Conclusion In conclusion, based on the considerations discussed above, ( 1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
4.0 ENVIRONMENTAL CONSIDERATION
A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22( c )(9). Therefore, pursuant to 10 CFR 51.22(b ), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.