ML24225A162
| ML24225A162 | |
| Person / Time | |
|---|---|
| Issue date: | 02/03/2025 |
| From: | Darrell Dunn NRC/NMSS/DFM/IOB |
| To: | |
| References | |
| DG-3058, RG-3.078, Rev 0 | |
| Download: ML24225A162 (4) | |
Text
Response to Public Comments on Draft Regulatory Guide DG-3058, Acceptable ASME Section XI Inservice Inspection Code Cases for 10 CFR Part 72 On July 17, 2024, the U.S. Nuclear Regulatory Commission (NRC) published a notice in Volume 89 of the Federal Register (FR)
(89 FR 58080) announcing the availability for public comment of Draft Regulatory Guide (DG)-3058, Acceptable ASME Section XI Inservice Inspection Code Cases for 10 CFR Part 72, for proposed new Regulatory Guide (RG) 3.78. The public comment period ended on August 16, 2024. The NRC received the comments listed below. The comment documents are available in the NRCs Agencywide Documents Access and Management System at the accession numbers given.
Mr. Mark Richter Nuclear Energy Institute 1201 F Street, NW, Suite 1100 Washington, DC 20004 Telephone: (202) 439-0954 Email: mar@nei.org ML24234A089 NEI Member via email Sept 19, 2024, from Mark Richter Telephone: NA Email: mar@nei.org ML24345A161 NRC ID # Commenter Comment Number Text of Comment NRC Resolution 1
Mark Richter Comment 1 NEI commends the NRC staff for using ISFSI service environment and material performance data in the development of DG-3058, including enabling modification of inspection intervals based on susceptibility criteria, recommending the use of 72.48 to adopt the Code Case without an amendment, recognizing the transformation of non-chloride salts into sodium sulfate and nitrite which act as CISCC inhibitors, and recognizing testing results that demonstrate that CISCC Thank you for the comment.
There was no change made to the final regulatory guide in response to the comment.
Response to Public Comments on Draft Regulatory Guide (DG)-3058 2
of austenitic stainless steel welds at low-susceptibility sites is very unlikely.
2 Mark Richter Comment 2 NEI agrees with the staff decision rationale and implementation conclusion reflected in the associated draft regulatory analysis - this guidance will result in total quantified benefits that exceed the relatively small costs of implementation. DG-3058 is a noteworthy example of applying risk insights to improve the regulatory framework.
Thank you for the comment.
There was no change made to the final regulatory guide in response to the comment.
3 Mark Richter Comment 3 NEI offers one specific comment for improvement, related to the additional alternative staff offers to ASME CC N-860, Subarticle-2700, Subsubarticle-2720, Changes to Inspection Interval. For ISFSIs with a CISCC susceptibility criteria of 3 or less and three consecutive inspections with consistent results, an inspection interval of 40 years may be established. NEI suggests that additional staff guidance regarding the process for crediting previous inspections will be helpful in the implementation of the alternative and establishing the 40-year inspection interval.
Thank you for the comment.
The staff agrees, in part, and has revised the Regulatory Guide to address this comment. The staff agrees that an inspection interval of 40 years can be established using the staffs alternative. Specifically, the staffs additional alternative to CC N-860 permits a 40-year inspection interval, so long as the ISFSI has susceptibility ranking of 3 or less and the other requirements of CC N-860 are met.
The staff clarifies that 3 consecutive inspections with consistent results, while required by ASME CC N-860, Subarticle-2700, Subsubarticle-2720, Changes to Inspection Interval, do not need to be completed under the staffs alternative to N-860.
The staff revised the final RG to more clearly state the criteria that should be met to increase the inspection interval to a maximum of 40 years using the results of
Response to Public Comments on Draft Regulatory Guide (DG)-3058 3
previous inspections. The revised guidance is that sites should meet the following criteria:
- 1. The site should have a CISCC ranking of 1 to 3 as determined using the criteria in EPRI-3002005371.
- 2. The most recent inspection was conducted in accordance with ASME CC N-860 article -2000, Inservice Inspection.
- 3. The results of the previous inspection should satisfy the requirements of ASME CC N-860, Subparagraph-2720(a) which are either (1) the screening examinations conclude no visual anomalies are present [as described in ASME CC N-860 -2710(a) and -2222(a)], or (2) the visual anomalies that are present are consistent with prior results and there is no prior history of stress corrosion cracking at the site.
- 4. The inservice inspection results documented in accordance with ASME Code Case N-860, subarticle -3130, Canister Inservice Inspection Report.
- 5. Revisions to inspection intervals are documented in accordance with the requirements in ASME Code Case N-860, subarticle -3120, Inservice Inspection Plans and Schedules.
4 NEI member via Mark Richter Comment 4 It would be helpful for the RG to explicitly state that if a licensee did not have code case N-860 in effect at the time, a utility may still set their inspection internal interval to 40 years after three satisfactory inspections per the NRC alternative in the Reg Guide. This may be justified by the licensee performing a reconciliation. It would also be The staff does not agree with the comment. The staff declines to provide guidance for setting an inspection interval when code case N-860 is not used because there is variability in the respective licensees aging management programs (AMPs) for the specific storage systems at the sites. As a result, there may be differences between N-860 and a licensees AMPs that must be considered prior to extending the inspection interval. If such a change is desired, a licensee may use the change process in 10 CFR 72.48 or apply for an amendment.
Response to Public Comments on Draft Regulatory Guide (DG)-3058 4
nice if the NRC clarified that a licensee would not have to adopt the code case entirely if they used it to justify lengthening the internal interval, since the AMPs and use of the code adoption is typically set by the CoC holder.