2013-16586. Proposed Revision to Treatment of Non-Safety Systems for Passive Advanced Light Water Reactors

AGENCY:

Nuclear Regulatory Commission.

ACTION:

Standard review plan-draft section revision; request for comment and use; re-notice.

SUMMARY:

The U.S. Nuclear Regulatory Commission (NRC) is re-noticing the solicitation for public comment published in the Federal Register on October 12, 2012 (77 FR 62270), on the NUREG-0800, “Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition,” on a proposed new section to its Standard Review Plan (SRP), Section 19.3, “Regulatory Treatment of Non-Safety Systems (RTNSS) for Passive Advanced Light Water Reactors.” The NRC seeks public comment on a narrow area of focus related to a revised position on the treatment of the high winds external hazard for certain RTNSS structures, systems, and components.

DATES:

Submit comments by August 9, 2013. Comments received after this date will be considered, if it is practical to do so, but the Commission is able to ensure consideration only for comments received on or before this date.

ADDRESSES:

You may access information and comment submissions related to this document, which the NRC possesses and are publicly available, by searching on http://www.regulations.gov under Docket ID NRC-2013-0150. You may submit comments by any of the following methods:

• Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2013-0150. Address questions about NRC dockets to Carol Gallagher; telephone: [phone]; email: [e-mail].
• Mail comments to: Cindy Bladey, Chief, Rules, Announcements, and Directives Branch (RADB), Office of Administration, Mail Stop: 3WFN 6-A56 U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.
• For additional direction on accessing information and submitting comments, see “Accessing Information and Submitting Comments” in the SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT:

Mr. Jonathan DeGange, Office of New Reactors, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone: [phone], email: mailto:[e-mail].

SUPPLEMENTARY INFORMATION:

I. Accessing Information and Submitting Comments

A. Accessing Information

Please refer to Docket ID NRC-2013-0150 when contacting the NRC about the availability of information regarding this document. You may access information related to this document, which the NRC possesses and are publicly available, by any of the following methods:

• Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2013-XXX.
• NRC's Agencywide Documents Access and Management System (ADAMS): You may access publicly available documents online in the NRC Library at http://www.nrc.gov/​reading-rm/​adams.html. To begin the search, select “ADAMS Public Documents” and then select “Begin Web-based ADAMS Search.” For problems with ADAMS, please contact the NRC's Public Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or by email to [e-mail]. The ADAMS accession number for each document referenced in this notice (if that document is available in ADAMS) is provided the first time that a document is referenced. The SRP Section 19.3 is re-noticed in its entirety under ADAMS Accession ML13081A756.
• NRC's PDR: You may examine and purchase copies of public documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 Rockville Pike, Rockville, MD 20852.

B. Submitting Comments

Please include Docket ID NRC-2013-0150 in the subject line of your comment submission, in order to ensure that the NRC is able to make your comment submission available to the public in this docket.

The NRC cautions you not to include identifying or contact information that you do not want to be publicly disclosed in your comment submission. The will NRC posts all comment submissions at http://www.regulations.gov as well as enter the comment submissions into ADAMS. The NRC does not routinely edit comment submissions to remove identifying or contact information.

If you are requesting or aggregating comments from other persons for submission to the NRC, then you should inform those persons not to include identifying or contact information that they do not want to be publicly disclosed in their comment submission. Your request should state that the NRC does not routinely edit comment submissions to remove such information before making the comment submissions available to the public or entering the comment submissions into ADAMS.

II. Further Information

This re-notice includes a revised position on treatment of the high winds external hazard for certain RTNSS structures, systems and components (SSCs). This position differs from the one described in the previously issued draft Section 19.3 of NUREG-0800 (ADAMS Accession No: ML12128A405) and from the alternative proposed from public comments (ML12319A465) on the previously issued draft Section 19.3 of NUREG-0800, which, during a public meeting held on January 22, 2013, the staff agreed to consider. Consequently, public stakeholders have not had an opportunity to comment on this approach to treatment of the high winds hazard for certain RTNSS SSCs.

The staff's original position on treatment of the high winds external hazard is documented in a memorandum from L. Joseph Callan, US NRC Executive Director for Operations to Chairman Jackson, US NRC dated June 23, 1997 (ML003708229) and entitled: “Implementation of Staff Position in SECY-96-128, `Policy and Key Technical Issues Pertaining to the Westinghouse AP600 Standard Pressurized Reactor Design', Related to Post-72 Hour Actions”. At that time, the NRC was concerned with the ability of a severe hurricane to cause an extended loss of reliable offsite AC power for a period longer than 72 hours. Consequently, the NRC took the position that it was reasonable and practical to design post-72 hour SSCs (most notably non-safety related diesel generators and their enclosure) to withstand a Category 5 hurricane and associated wind-borne missiles; but, these SSCs should not be required to withstand tornado loads and tornado missiles. Also at the time, tornado loads and missiles were considered generally to lead to more restrictive design requirements.

Since this position was established in the mid-1990s, Regulatory Guide 1.76 has been revised using the Enhanced Fujita Scale, resulting in a significant decrease to the maximum design basis tornado wind speeds, and new guidance (Regulatory Guide 1.221) has been issued for addressing hurricanes and associated hurricane missiles. In addition, recent operating experience shows that tornado wind events can also cause an extended loss of reliable offsite AC power for more than 72 hours. Lastly, application of the guidance described in the memorandum referenced above could, in some cases, result in a level of treatment for non-safety related SSCs which meet Criterion B for RTNSS that is higher than the level for safety-related SSCs. Therefore, the RTNSS missile protection guidance described in the memorandum is no longer appropriate. The NRC's position now is that RTNSS “B” SSCs should be protected from both tornadoes and hurricanes and the missiles they might create, and that applicants should choose the design basis wind speeds for RTNSS “B” SSCs using the guidance in Regulatory Guides 1.76 and 1.221. Standard Review Plan 19.3 has been revised to reflect this position.

The NRC seeks public comment on a narrow area of focus in the reissuance of the SRP Section 19.3, “Regulatory Treatment of Non-Safety Systems (RTNSS) for Passive Advanced Light Water Reactors.” This area includes a revised position on treatment of the high winds external hazard for certain RTNSS SSCs that is described above and elsewhere (ML13081A756) under section “SRP Acceptance Criteria” and in “Area of Review—Augmented Design Standards” shown as item 4 in the guidance document page 19.3-8.

Following NRC staff evaluation of public comments, the NRC intends to incorporate the final approved guidance into the next revision of NUREG-0800.

Backfitting and Issue Finality

This draft SRP, if finalized, would provide guidance to the staff for reviewing applications for a construction permit and an operating license under part 50 of Title 10 of the Code of Federal Regulations (10 CFR) with respect to the regulatory treatment of non-safety systems. The draft SRP would also provide guidance for reviewing an application for a standard design approval, a standard design certification, a combined license, and a manufacturing license under part 52 of Title 10 of the Code of Federal Regulations (10 CFR) with respect to these same subject matters.

Issuance of this draft SRP, if finalized, would not constitute backfitting as defined in 10 CFR 50.109, or otherwise be inconsistent with the issue finality provisions in 10 CFR part 52. The staff's position is based upon the following considerations.

1. The draft SRP positions, if finalized, do not constitute backfitting, inasmuch as the SRP is internal guidance to NRC staff.

The SRP provides interim guidance to the staff on how to review an application for NRC regulatory approval in the form of licensing. Changes in internal staff guidance are not matters for which applicants or licensees are protected under 10 CFR 50.109 or issue finality provisions in 10 CFR Part 52.

2. Backfitting and issue finality—with certain exceptions discussed below—do not protect current or future applicants.

Applicants and potential applicants are not, with certain exceptions, protected by either the Backfit Rule or any issue finality provisions under 10 CFR part 52. This is because neither the Backfit Rule nor the issue finality provisions under 10 CFR part 52—with certain exclusions discussed below—were intended to apply to every NRC action which substantially changes the expectations of current and future applicants.

The exceptions to this general principle are applicable whenever an applicant references a 10 CFR Part 52 license (e.g., an early site permit) and/or NRC regulatory approval (e.g., a design certification rule) with specified issue finality provisions. The staff does not, at this time, intend to impose the positions represented in the draft SRP section (if finalized) in a manner that is inconsistent with any issue finality provisions. If, in the future, the staff seeks to impose a position in the draft SRP section (if finalized) in a manner which does not provide issue finality as described in the applicable issue finality provision, then the staff must address the criteria for avoiding issue finality as described in the applicable issue finality provision.

3. The staff has no intention to impose the draft SRP positions on existing nuclear power plant licenses or regulatory approvals either now or in the future (absent a voluntary request for change from the licensee, holder of a regulatory approval, or a design certification applicant).

The staff does not intend to impose or apply the positions described in the draft SRP section to existing (already issued) licenses (e.g., operating licenses and combined licenses) and regulatory approvals—in this case, design certifications. Hence, the draft SRP—even if considered guidance which is within the purview of the issue finality provisions in 10 CFR part 52—need not be evaluated as if it were a backfit or as being inconsistent with issue finality provisions. If, in the future, the staff seeks to impose a position in the draft SRP (if finalized) on holders of already issued licenses in a manner which does not provide issue finality as described in the applicable issue finality provision, then the staff must make the showing as set forth in the Backfit Rule, or address the criteria for avoiding issue finality as described applicable issue finality provision, as applicable.

Dated at Rockville, Maryland, this 28th day of June 2013.

For the Nuclear Regulatory Commission.

Joseph Colaccino,

Chief, Policy Branch, Division of Advanced Reactors and Rulemaking, Office of New Reactors.