[Federal Register Volume 81, Number 224 (Monday, November 21, 2016)]
[Notices]
[Pages 83288-83289]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-27903]


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NUCLEAR REGULATORY COMMISSION

[NRC-2016-0233]


Pressurized Water Reactor Control Rod Ejection and Boiling Water 
Reactor Control Rod Drop Accidents

AGENCY: Nuclear Regulatory Commission.

ACTION: Draft regulatory guide; request for comment.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for 
public comment draft regulatory guide (DG) DG-1327, ``Pressurized Water 
Reactor Control Rod Ejection and Boiling Water Reactor Control Rod Drop 
Accidents.'' This DG proposes new guidance for analyzing accidents such 
as control rod ejection for pressurized water reactors and control rod 
drop for boiling-water reactors. It defines fuel cladding failure 
thresholds for ductile failure, brittle failure, and pellet-clad 
mechanical interaction and provides radionuclide release fractions for 
use in assessing radiological consequences. It also describes 
analytical limits and guidance for demonstrating compliance with 
regulations governing reactivity limits.

DATES: Submit comments by February 21, 2017. Comments received after 
this date will be considered if it is practical to do so, but the NRC 
is able to ensure consideration only for comments received on or before 
this date. Although a time limit is given, comments and suggestions in 
connection with items for inclusion in guides currently being developed 
or improvements in all published guides are encouraged at any time.

ADDRESSES: You may submit comments by any of the following methods 
(unless this document describes a different method for submitting 
comments on a specified subject):
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2016-0233. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: [email protected]. For technical questions, contact 
the individuals listed in the FOR FURTHER INFORMATION CONTACT section 
of this document.
     Mail comments to: Cindy Bladey, Office of Administration, 
Mail Stop: OWFN-12H-08, U.S. Nuclear Regulatory Commission, Washington, 
DC 20555-0001.
    For additional direction on accessing information and submitting 
comments, see ``Obtaining Information and Submitting Comments'' in the 
SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: Paul Clifford, Office of Nuclear 
Reactor Regulation, telephone: 301-415-4043, email: 
[email protected] and Edward O'Donnell, Office of Nuclear 
Regulatory Research, telephone: 301-415-3317 email: 
[email protected]. Both are staff of the U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001.

SUPPLEMENTARY INFORMATION: 

I. Obtaining Information and Submitting Comments

A. Obtaining Information

    Please refer to Docket ID NRC-2016-0233 when contacting the NRC 
about the availability of information regarding this action. You may 
obtain publically-available information related to this action, by any 
of the following methods:
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2016-0233.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly available documents online in the 
ADAMS Public Documents collection 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 [email protected]. The 
DG is electronically available in ADAMS under Accession No. 
ML16124A200.
     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, Maryland 20852.

B. Submitting Comments

    Please include Docket ID NRC-2016-0233 in your comment submission. 
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 NRC posts all comment submissions at http://www.regulations.gov as well as enters the comment submissions into 
ADAMS.

[[Page 83289]]

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. Additional Information

    The NRC is issuing for public comment a DG in the NRC's 
``Regulatory Guide'' series. This series was developed to describe and 
make available to the public information regarding methods that are 
acceptable to the NRC staff for implementing specific parts of the 
NRC's regulations, techniques that the staff uses in evaluating 
specific issues or postulated events, and data that the staff needs in 
its review of applications for permits and licenses.
    The DG, entitled ``Pressurized Water Reactor Control Rod Ejection 
and Boiling Water Reactor Control Rod Drop Accidents,'' is a proposed 
new guide temporarily identified by its task number, DG-1327. DG-1327 
proposes new guidance for analyzing reactivity-initiated accidents such 
as control rod ejection for pressurized water reactors and control rod 
drop for boiling-water reactors. It defines fuel cladding failure 
thresholds for ductile failure, brittle failure, and pellet-clad 
mechanical interaction and provides radionuclide release reactions for 
use in assessing radiological consequences. It also describes 
analytical limits and guidance for demonstrating compliance with 
regulations governing reactivity limits.
    The draft guide also incorporates new empirical data from in-pile, 
prompt power pulse test programs and analyses from several 
international publications on fuel rod performance under reactivity 
initiated accident conditions to provide guidance on acceptable 
analytical methods, assumptions, and limits for evaluating a 
pressurized water reactor control rod ejection accident.
    The draft guide expands the existing guidance for control rod 
ejection accidents in Regulatory Guide (RG) 1.77, ``Assumptions Used 
for Evaluation a Control Rod Ejection Accident for Pressurized Water 
Reactors.'' However, the NRC intends to maintain RG 1.77 for existing 
licensees who do not make any design changes within the scope of RG 
1.77.

III. Backfitting and Issue Finality

    Draft regulatory guide DG-1327 describes one acceptable method for 
demonstrating compliance with Appendix A of part 50 of title 10 of the 
Code of Federal Regulations (10 CFR), ``General Design Criteria 28, 
Reactivity Limit,'' with respect to control rod ejection (CRE) for 
pressurized-water reactors (PWRs) and a control rod drop (CRD) for 
boiling-water reactors (BWRs). It addresses fuel cladding failure 
thresholds for ductile failure, brittle failure, and pellet-clad 
mechanical interaction (PCMI), provides radionuclide release fractions 
for use in assessing radiological consequences, and describes 
analytical limits and guidance for demonstrating compliance with GDC 28 
governing reactivity limits.
    This draft regulatory guide, if finalized, would not constitute 
backfitting as defined in 10 CFR 50.109 (the Backfit Rule) and is not 
otherwise inconsistent with the issue finality provisions in 10 CFR 
part 52, ``Licenses, Certifications and Approvals for Nuclear Power 
Plants.'' Existing licensees and applicants of final design 
certification rules will not be required to comply with the positions 
set forth in this draft regulatory guide, unless the licensee or design 
certification rule applicant seeks a voluntary change to its licensing 
basis with respect to CRE for PWRs or CRD for BWRs, and where the NRC 
determines that the safety review must include consideration of these 
events. Further information on the staff's use of the draft regulatory 
guide, if finalized, is contained in the draft regulatory guide under 
Section D. Implementation.
    Applicants and potential applicants are not, with certain 
exceptions, protected by either the Backfit Rule or any issue finality 
provisions under part 52. Neither the Backfit Rule nor the issue 
finality provisions under 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. Therefore, 
the positions in any final draft regulatory guide, if imposed on 
applicants, would not represent backfitting (except as discussed 
below).
    The exceptions to the general principle are applicable whenever a 
combined license applicant references a part 52 license (i.e., an early 
site permit or a manufacturing license) and/or part 52 regulatory 
approval (i.e., a design certification rule or design approval. The 
staff does not, at this time, intend to impose the positions 
represented in the draft regulatory guide in a manner that is 
inconsistent with any issue finality provisions in these part 52 
licenses and regulatory approvals. If, in the future, the staff seeks 
to impose a position in this regulatory guide in a manner which does 
not provide issue finality as described in the applicable issue 
finality provision, then the staff will address the criteria for 
avoiding issue finality as described in the applicable issue finality 
provision.

    Dated at Rockville, Maryland, this 10th day of November 2016.

    For the Nuclear Regulatory Commission.
Thomas H. Boyce,
Chief, Regulatory Guidance and Generic Issues Branch, Division of 
Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2016-27903 Filed 11-18-16; 8:45 am]
 BILLING CODE 7590-01-P