[Federal Register Volume 79, Number 74 (Thursday, April 17, 2014)]
[Notices]
[Pages 21811-21812]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-08792]


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NUCLEAR REGULATORY COMMISSION

[NRC-2014-0023]


Effect of LWR Coolant Environments on the Fatigue Life of Reactor 
Materials

AGENCY: Nuclear Regulatory Commission.

ACTION: Draft NUREG; request for comment.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for 
public comment a draft NUREG, NUREG/CR-6909, Revision 1, ``Effect of 
LWR Coolant Environments on the Fatigue Life of Reactor Materials.'' 
This report summarizes the results of NRC research efforts and work 
performed at Argonne National Laboratory on the fatigue of piping and 
pressure vessel steels in light water reactor environments. Revision 1 
of this report provides updates and improvements to the environmental 
fatigue correction factor approach based on an extensive update to 
available laboratory fatigue data from testing and results available 
since this report was first published in 2007.

DATES: Submit comments by June 2, 2014. 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 before this 
date.

ADDRESSES: You may submit comments by any of the following methods 
(unless this document describes a different method for submitting 
comments on a specific subject):
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2014-0023. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-287-
3422; email: [email protected]. For technical questions, contact 
the individual listed in the FOR FURTHER INFORMATION CONTACT section of 
this document.
     Mail comments to: Cindy Bladey, Chief, Rules, 
Announcements, and Directives Branch, Office of Administration, Mail 
Stop: 3WFN-06-44M, 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: Gary Stevens, Office of Nuclear 
Regulatory Research, U.S. Nuclear Regulatory Commission, Washington DC 
20555-0001; telephone: 301-251-7569, email: [email protected].

SUPPLEMENTARY INFORMATION: 

I. Accessing Information and Submitting Comments

A. Accessing Information

    Please refer to Docket ID NRC-2014-0023 when contacting the NRC 
about the availability of information regarding this document. You may 
access publicly-available information related to this document by any 
of the following methods:
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2014-0023.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may access 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 
draft of NUREG/CR-6909, Revision 1 is available in ADAMS under 
Accession No. ML14087A068.
     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-2014-0023 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 you 
comment submission. The NRC will post 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. Discussion

    The American Society of Mechanical Engineers Boiler and Pressure 
Vessel Code (Code) provides rules for the design of Class 1 components 
of nuclear power plants. Appendix I to Section III of the Code contains 
fatigue design curves for applicable structural materials. However, the 
effects of light water reactor coolant environments are

[[Page 21812]]

not explicitly addressed by the Code design curves. The existing 
fatigue strain-vs.-life data illustrate potentially significant effects 
of light water reactor coolant environments on the fatigue resistance 
of pressure vessel and piping steels. Under certain environmental and 
loading conditions, fatigue lives in water relative to those in air can 
be significantly lower for austenitic stainless, nickel alloy, carbon 
and low-alloy steels. In March 2007, Revision 0 of NUREG/CR-6909 (ADAMS 
Accession No. ML070660620) was issued and it was the technical basis 
document for NRC Regulatory Guide 1.207, ``Guidelines for Evaluating 
Fatigue Analyses Incorporating the Life Reduction of Metal Components 
Due to the Effects of the Light-Water Reactor Environment for New 
Reactors.'' Revision 0 of NUREG/CR-6909 summarized the work performed 
at Argonne National Laboratory on the fatigue of piping and pressure 
vessel steels in light water reactor coolant environments. In that 
document, the existing laboratory fatigue data were evaluated to 
identify the various materials, environmental, and loading parameters 
that influence fatigue crack initiation, and document the effects of 
key parameters on the fatigue lives of pressure vessel and piping 
steels. The report presented fatigue life models for estimating fatigue 
lives as a function of material, loading, and environmental conditions, 
and described the environmental fatigue correction factor for 
incorporating the effects of light water reactor coolant environments 
into Code fatigue evaluations.
    Revision 1 of NUREG/CR-6909 provides updates and improvements to 
the environmental fatigue correction factor approach based on an 
extensive update to the laboratory fatigue data from testing and 
results available since 2007. The NRC is particularly interested in 
stakeholder feedback on the following three areas:
    i. The extension of the best-fit mean air curve for ferritic steels 
discussed in Section 3.1.10.
    ii. The air fatigue design curve adjustment factors summarized in 
Section 5.5.
    iii. Accuracy check of the technical content of the NUREG, 
particularly with respect to all of the numerical content of the 
report.

    Dated at Rockville, Maryland, this 9th day of April, 2014.

    For the Nuclear Regulatory Commission.
David L. Rudland,
Chief, Component Integrity Branch, Division of Engineering, Office of 
Nuclear Regulatory Research.
[FR Doc. 2014-08792 Filed 4-16-14; 8:45 am]
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