ML080440173
| ML080440173 | |
| Person / Time | |
|---|---|
| Issue date: | 02/14/2008 |
| From: | Veronica Rodriguez NRC/NRR/ADRA/DPR/PRAB |
| To: | Arey M, Jeffrey Riley Nuclear Energy Institute, PWR Owners Group |
| Rodriguez V NRR/DLR/RLRB 415-3703 | |
| References | |
| RIN 3150-AI01, RM-668 | |
| Download: ML080440173 (5) | |
Text
February 14, 2008 Melvin L. Arey, Jr., MSC Chairman PWR Owners Group Program Management Office 20 International Drive Windsor, CT 06095 James H. Riley, Director Engineering Nuclear Generation Division Nuclear Energy Institute 1776 I Street, NW - Suite 400 Washington, DC 20006-3708
SUBJECT:
SUMMARY
OF TELEPHONE CONFERENCE CALL HELD ON JANUARY 22, 2008, CONCERNING COMMENTS RELATED TO THE PROPOSED RULE ON THE ALTERNATE FRACTURE TOUGHNESS REQUIREMENTS FOR PROTECTION AGAINST PRESSURIZED THERMAL SHOCK EVENTS (RIN 3150-AI01, RM-668)
The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of the Pressurized Water Reactor Owners Group (PWROG) and Nuclear Energy Institute (NEI) held a telephone conference call on January 22, 2008. The purpose of the telephone conference call was to clarify comments provided by PWROG and NEI on the subject proposed rule.
provides a list of the participants and Enclosure 2 contains a list of the comments discussed, including a summary of the discussion.
/RA/
Veronica M. Rodriguez, Project Manager Regulatory Analysis, Policy and Rulemaking Division of Policy and Rulemaking Office of Nuclear Reactor Regulations
Enclosures:
- 1. List of Participants
- 2. List of Comments
ML080440173 OFFICE PM:PRAB:DPR BC:PRAB:DPR NAME VRodriguez JZimmerman DATE 02/14/2008 02/14/2008 PROPOSED RULE ON THE ALTERNATE FRACTURE TOUGHNESS REQUIREMENTS FOR PROTECTION AGAINST PRESSURIZED THERMAL SHOCK EVENTS (RIN 3150-AI01, RM-668)
TELEPHONE CONFERENCE CALL LIST OF PARTICIPANTS January 22, 2008 PARTICIPANTS AFFILIATIONS Veronica M. Rodriguez Nuclear Regulatory Commission (NRC)
Barry Elliot NRC Mark Kirk NRC Ted Meyer Pressurized Water Reactor Owners Group (PWROG)
Cheryl Bogges PWROG Steve Burn PWROG Mel Arey PWROG Nathan Palm PWROG Bruce Bishop PWROG Randy Lott PWROG Mike Melton Nuclear Energy Institute
PROPOSED RULE ON THE ALTERNATE FRACTURE TOUGHNESS REQUIREMENTS FOR PROTECTION AGAINST PRESSURIZED THERMAL SHOCK EVENTS (RIN 3150-AI01, RM-668)
TELEPHONE CONFERENCE CALL COMMENTS DISCUSSED January 22, 2008 The U.S. Nuclear Regulatory Commission (NRC or the staff) held a telephone conference call on January 22, 2008 to clarify comments provided on the subject proposed rule. The following comments were discussed.
Comment 1:
Industry bodies should be used to establish a single consensus embrittlement trend curve (ETC) that is acceptable for use in 10 CFR 50.61 and other NRC regulations. The consensus ETC should allow evaluation based on reasonably available data and provide accurate predictions of the transition temperature for individual plants. Although the ETC defined in equations 5 through 7, and described in section (f) of the proposed rule, provides a reasonable description of generic behavior for use in the probabilistic studies, there is no consensus or use of these equations in providing best estimate predictions for transition temperature shifts in individual plants.
Presentations at recent ASTM E10.02 Subcommittee meetings indicate that both industry and the Office of Research in the NRC are currently working on improved ETCs that are expected to eventually become the basis for revisions to ASTM E900 and NRC Regulatory Guide 1.99. If these revised ETCs are adopted as industry consensus curves, there is a strong possibility that the NRC regulations will include three distinctly different equations for calculating the same parameter (DT30).
This optional section of 10 CFR 50.61 will only apply to a handful of plants. This confusion in the regulation could be avoided if the optional portion of the regulation required use of an NRC approved methodology rather than the specific trend curve.
Discussion: The staff stated that the purpose of this comment is unclear. The staff requested that the commenter clarify the intent of the comment and explain why this proposal is needed.
The commenter stated that one of the main concerns is to maintain consistency among the regulatory documents (i.e., the proposed rule, Regulatory Guide 1.99, and ASME E-900). The commenter stated that the current methodology proposed in these documents is not consistent and that it will be ideal if they were all the same. The commenter also explained that the industry is currently evaluating several alternative methodologies and that a consensus as to which one is the most appropriate has not been reached.
The staff noted the explanation provided by the commenter. The NRC will publish the formal response to this comment in the Federal Register.
Comment 2:
There are a number of technical concerns with the embedded flaw limits for welds and plates in Tables 2 and 3, respectively, of the voluntary pressurized thermal shock (PST) rule that was proposed by the NRC. It is suggested that the NRC have a technical meeting with industry to discuss these concerns and resolve them before the final version of the voluntary PTS rule is published for use.
Discussion: The staff stated that the intent of this comment is unclear. The staff clarified that the public was provided with a 75 day period to provide comments related to the proposed rule.
The staff explained that additional meetings to collect comments after this period has been closed are not commonly performed as this is not part of the NRC rulemaking process.
Therefore, the staff requested that the commenter explain what would be the purpose of the proposed meeting.
The commenter clarified that a detailed list with concerns related to this comment was provided in writing to the NRC during the comment period. The commenter clarified that the intent of the comment was to inform the NRC that, if needed, the industry will be available to provide clarifications regarding this detailed list during a meeting or a telephone conference.
The staff informed the commenter that this detailed list is currently under evaluation. The staff noted that a separate meeting was not needed. The staff explained that if clarification questions emerged, a telephone conference will be scheduled with the commenter.
The NRC will publish the formal response to this comment in the Federal Register.