82 FR 13875 - Assessment of Abnormal Radioactive Discharges in Ground Water to the Unrestricted Area at Nuclear Power Plant Sites

NUCLEAR REGULATORY COMMISSION

Federal Register Volume 82, Issue 49 (March 15, 2017)

The U.S. Nuclear Regulatory Commission (NRC) is issuing Regulatory Guide (RG) 4.25, ``Assessment of Abnormal Radioactive Discharges in Ground Water to the Unrestricted Area at Nuclear Power Plant Sites,'' as a new guide (Revision 0). The guide describes an approach that the NRC staff considers acceptable for use in assessing abnormal discharges of radionuclides in ground water from the subsurface to the unrestricted area at commercial nuclear power plant sites.

[Federal Register Volume 82, Number 49 (Wednesday, March 15, 2017)]
[Notices]
[Pages 13875-13876]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-05170]


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NUCLEAR REGULATORY COMMISSION

[NRC-2015-0272]


Assessment of Abnormal Radioactive Discharges in Ground Water to 
the Unrestricted Area at Nuclear Power Plant Sites

AGENCY: Nuclear Regulatory Commission.

ACTION: Regulatory guide; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing 
Regulatory Guide (RG) 4.25, ``Assessment of Abnormal Radioactive 
Discharges in Ground Water to the Unrestricted Area at Nuclear Power 
Plant Sites,'' as a new guide (Revision 0). The guide describes an 
approach that the NRC staff considers acceptable for use in assessing 
abnormal discharges of radionuclides in ground water from the 
subsurface to the unrestricted area at commercial nuclear power plant 
sites.

DATES: Revision 0 to RG 4.25 is available on March 15, 2017.

ADDRESSES: Please refer to Docket ID NRC-2015-0272 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly-available information related to this document 
using any of the following methods:
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2015-0272. 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 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]. 
Regulatory Guide 4.25 is available in ADAMS under Accession No. 
ML16253A333.
     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: Thomas Nicholson, telephone: 301-415-
2471, email: [email protected]; and Edward O'Donnell, telephone: 
301-415-3317, email: [email protected]. Both are staff members of 
the Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001.

SUPPLEMENTARY INFORMATION:

I. Discussion

    The NRC is issuing a new guide 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 agency's regulations, 
techniques that the NRC staff uses in evaluating specific issues or 
postulated events, and data that the NRC staff needs in its review of 
applications for permits and licenses.
    Revision 0 of RG 4.25 was issued with a temporary identification of 
Draft Regulatory Guide, DG-4025. The guide is being issued to provide 
guidance to licensees on acceptable methods to determine the quantity 
of licensed material (i.e., radionuclides) in abnormal discharge into 
the unrestricted area through the ground water discharge pathway at 
commercial nuclear power plants. American National Standards Institute/
American Nuclear Society (ANSI/ANS)-2.17-2010 (R2016), ``Evaluation of 
Subsurface Radionuclide Transport at Commercial Nuclear Power Plants,'' 
provides such methods. The

[[Page 13876]]

ANSI/ANS standard does not specify the use of any specific ground water 
flow and transport model. It provides a graded, risk-informed approach 
for evaluating the effects of subsurface radionuclide transport. The 
ground water flow and transport model developed by licensees should be 
a site-specific model, based on the complexity of geologic and 
hydrologic conditions, the types of radioactive materials and facility 
design, the types and effectiveness of engineered and natural barriers, 
and the proximity to surface water and ground water receptors. A 
facility that has less significant radionuclide source term, minor 
subsurface contamination, simple or well-understood hydrogeology, or 
limited effects on ground water resources generally requires less 
extensive site characterization, mathematical modeling, and 
performance-confirmation measures than a facility with significant 
residual radioactivity that has the potential to exceed national 
radiation protection standards. The appendix to RG 4.25 provides a 
simple ground water flow and transport model that is acceptable for use 
with simple hydrogeologic conditions and geometry such as steady-state 
saturated flow in homogeneous porous sand layers.

II. Additional Information

    The DG-4025 was published in the Federal Register on December 11, 
2015 (80 FR 77028) for a 60-day public comment period. The public 
comment period closed on February 9, 2016. Public comments on DG-4025 
and the staff responses to the public comments are available under 
ADAMS under Accession No. ML16253A330.

III. Congressional Review Act

    This RG is a rule as defined in the Congressional Review Act (5 
U.S.C. 801-808). However, the Office of Management and Budget has not 
found it to be a major rule as defined in the Congressional Review Act.

IV. Backfitting and Issue Finality

    Regulatory Guide 4.25 describes a method that the staff of the NRC 
considers acceptable for assessing abnormal, inadvertent radioactive 
releases which may result in discharges of contaminated ground water 
from the subsurface to the unrestricted area at commercial nuclear 
power plant sites. Issuance of this RG does not constitute backfitting 
as defined in section 50.109 of title 10 of the Code of Federal 
Regulations (10 CFR) (the Backfit Rule) and is not otherwise be 
inconsistent with the issue finality provisions in 10 CFR part 52. As 
discussed in the ``Implementation'' section of this RG, the NRC has no 
current intention to impose this guide on holders of current operating 
licenses or combined licenses.
    This RG may be applied to applications for operating licenses, 
combined licenses, early site permits, and certified design rules 
docketed by the NRC as of the date of issuance of the final regulatory 
guide, as well as future applications submitted after the issuance of 
the regulatory guide. Such action would not constitute backfitting as 
defined in the Backfit Rule or be otherwise inconsistent with the 
applicable issue finality provision in 10 CFR part 52, inasmuch as such 
applicants or potential applicants are not within the scope of entities 
protected by the Backfit Rule or the relevant issue finality provisions 
in part 52.

    Dated: March 10, 2017.

    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. 2017-05170 Filed 3-14-17; 8:45 am]
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