[Federal Register Volume 82, Number 38 (Tuesday, February 28, 2017)]
[Notices]
[Pages 12142-12143]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-03891]


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NUCLEAR REGULATORY COMMISSION

[NRC-2017-0059]


Limit of Error Concepts and Principles of Calculation in Nuclear 
Materials Control

AGENCY: Nuclear Regulatory Commission.

ACTION: Regulatory guide: withdrawal.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is withdrawing 
Regulatory Guide (RG) 5.18, ``Limit of Error Concepts and Principles of 
Calculation in Nuclear Materials Control.'' This RG is being withdrawn 
because the term ``limit of error'' is no longer used in the material 
control and accounting (MC&A) requirements in NRC's regulations, and 
therefore the RG 5.18 guidance is no longer needed. The MC&A 
requirements now include the term ``standard error'' in place of the 
term ``limit of error.'' The ``standard error'' term is used in 
evaluating the significance of an inventory difference (ID). The NRC 
has issued guidance separately for the term ``standard error.''

DATES: The effective date of the withdrawal of RG 5.18 is February 28, 
2017.

ADDRESSES: Please refer to Docket ID NRC-2017-0059 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publically-available information related to this document, 
using the following methods:
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2017-0059. 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.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly-available documents online in the 
ADAMS Public Document 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 
ADAMS accession number for each document referenced (if it is available 
in ADAMS) is provided the first time that it is mentioned in this 
document. The basis for the withdrawal of this guide is in ADAMS under 
Accession No. ML16244A672.
     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.
    Regulatory guides are not copyrighted, and NRC approval is not 
required to reproduce them.

FOR FURTHER INFORMATION CONTACT: Glenn Tuttle, Office of Nuclear 
Materials Safety and Safeguards, telephone: 301-415-7230, email: 
[email protected]; and Harriet Karagiannis, Office of Nuclear

[[Page 12143]]

Regulatory Research, telephone: 301-415-2493, email: 
[email protected]. Both are staff members of the U.S. Nuclear 
Regulatory Commission, Washington, DC 20555-0001.

SUPPLEMENTARY INFORMATION: The NRC staff issued RG 5.18 in January 1974 
to provide guidance on meeting the material control and accounting 
(MC&A) requirements in part 70 of title 10 the Code of Federal 
Regulations (10 CFR), ``Domestic Licensing of Special Nuclear 
Material.'' Part 70 then contained MC&A requirements, including those 
in 10 CFR 70.51, ``Material Balance, Inventory, and Records 
Requirements'' that were established in 1973. Specifically, 10 CFR 
70.51(a)(5) defined the term ``Limit of error,'' and 10 CFR 70.51(e) 
required licensees to calculate statistical limits of error for any 
material unaccounted for as part of their MC&A procedures. Part 70 
regulations no longer contain any MC&A requirements, and licensees are 
no longer required to calculate statistical limits of error for any 
material unaccounted for. In 1985, 10 CFR part 74, ``Material Control 
and Accounting of Special Nuclear Material,'' was established, and in 
2002, the 10 CFR 70.51 requirements were transferred to 10 CFR part 74 
which now includes the current MC&A requirements. As part of the 2002 
MC&A revisions, the term ``limit of error'' was replaced by the term 
``standard error,'' and licensees are now required to calculate the 
``inventory difference'' (as defined in 10 CFR 74.4) rather than 
determining the amounts of material that are ``unaccounted for.'' The 
``standard error'' is used in evaluating the significance of an 
inventory difference (ID).
    Guidance for calculating the ``standard error'' of the ID is found 
in NUREG-1065, ``Acceptable Standard Format and Content for the 
Fundamental Nuclear Material Control (FNMC) Plan Required for Low-
Enriched Uranium Facilities'' (ADAMS Accession No. ML031340288), NUREG-
1280, ``Standard Format and Content Acceptance Criteria for the 
Material Control and Accounting (MC&A) Reform Amendment'' (ADAMS 
Accession No. ML13253A308), and NUREG/CR-5734, ``Recommendations to the 
NRC on Acceptable Standard Format and Content for the Fundamental 
Nuclear Material Control (FNMC) Plan Required for Low-Enriched Uranium 
Enrichment Facilities'' (ADAMS Accession No. ML15120A354).
    In addition, RG 5.18 endorsed the American National Standards 
Institute Standard N15.16-1974, ``Limit of Error Concepts and 
Principles of Calculation in Nuclear Materials Control,'' to provide 
guidance on the ``limit of error'' concept. However, this standard has 
been withdrawn from active status with no replacement.
    The NRC is withdrawing RG 5.18 because it is no longer needed. 
Withdrawal of an RG means that the guide no longer provides useful 
information or has been superseded by other guidance, technological 
innovations, congressional actions, or other events. The withdrawal of 
RG 5.18 does not alter any prior or existing NRC licensing approval or 
the acceptability of licensee commitments to RG 5.18. Although RG 5.18 
is withdrawn, current licensees may continue to use it, and withdrawal 
does not affect any existing licenses or agreements. However, 5.18 
should not be used in future requests or applications for NRC licensing 
actions.

    Dated at Rockville, Maryland, this 21st day of February 2017.

    For the Nuclear Regulatory Commission.
Harriet Karagiannis,
Acting Chief, Regulatory Guidance and Generic Issues Branch, Division 
of Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2017-03891 Filed 2-27-17; 8:45 am]
 BILLING CODE 7590-01-P