[Federal Register Volume 85, Number 243 (Thursday, December 17, 2020)]
[Proposed Rules]
[Pages 81848-81849]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-27364]



10 CFR Part 50

[Docket No. PRM-50-75; NRC-2002-0018]

Large Break Loss-of-Coolant Accident Redefinition

AGENCY: Nuclear Regulatory Commission.

ACTION: Petition for rulemaking; denial.


SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is denying a 
petition for rulemaking dated February 6, 2002, submitted by Anthony R. 
Pietrangelo on behalf of the Nuclear Energy Institute, due to the 
discontinuation of the associated rulemaking.

DATES: As of December 17, 2020, the docket for PRM-50-75 is closed.

ADDRESSES: Please refer to Docket ID NRC-2002-0018 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 Website: Go to https://www.regulations.gov and search for Docket ID NRC-2002-0018. Address 
questions about NRC dockets to Dawn Forder; telephone: 301-415-3407; 
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 https://www.nrc.gov/reading-rm/adams.html. To begin the search, 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 the SUPPLEMENTARY INFORMATION section.
     Attention: The PDR, where you may examine and order copies 
of public documents, is currently closed. You may submit your request 
to the PDR via email at [email protected] or call 1-800-397-4209 
between 8:00 a.m. and 4:00 p.m. (EST), Monday through Friday, except 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Yanely Malave, telephone: 301-415-
1519; email: [email protected]; or Robert Beall, telephone: 301-
415-3874; email: [email protected]. Both are staff of the Office of 
Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001.


I. Background

    Title 10 of the Code of Federal Regulations (10 CFR) 2.802, 
``Petition for rulemaking--requirements for filing,'' provides an 
opportunity for any interested person to petition the Commission to 
issue, amend, or rescind any regulation. On February 6, 2002, Anthony 
R. Pietrangelo, on behalf of the Nuclear Energy Institute (petitioner),

[[Page 81849]]

submitted a petition for rulemaking requesting that the NRC amend its 
regulations to allow licensees to use an alternative to the double-
ended guillotine break of the largest pipe in the reactor coolant 
system in emergency core cooling system (ECCS) evaluation models (ADAMS 
Accession No. ML082460625). The NRC docketed the petition as PRM-50-75, 
and on April 8, 2002, published a notice of docketing in the Federal 
Register and requested public comment (67 FR 16654). The comment period 
closed on June 24, 2002, and the NRC received 18 comment letters (ADAMS 
Accession No. ML022390515).
    After evaluating the merits of the petition and the public 
comments, the NRC determined that the issues raised in PRM-50-75 would 
be considered in the ongoing ``Risk-Informed Redefinition of Large 
Break Loss-of-Coolant Accident (LOCA) Emergency Core Cooling System 
(ECCS) Requirements'' rulemaking. On November 6, 2008, the NRC 
published a document in the Federal Register (73 FR 66000) stating that 
the NRC would address the substantive comments filed in PRM-50-75 as 
part of that rulemaking.

II. Discussion

A. Discontinuation of the Rulemaking

    On December 10, 2010, the NRC staff provided the Commission SECY-
10-0161, ``Final Rule: Risk-Informed Changes to Loss-of-Coolant 
Accident Technical Requirements (10 CFR 50.46a)(RIN 3150-AH29).'' 
Subsequent to the accident at Fukushima Dai-Ichi Nuclear Plant in March 
of 2011, the NRC staff requested Commission approval to withdraw the 
draft final rule during its evaluation of Fukushima Near-Term Task 
Force Recommendation 1 regarding the development of a new risk-informed 
regulatory framework from SECY-11-0093, ``Near-Term Report and 
Recommendations for Agency Actions Following The Events in Japan,'' and 
the recent publication of NUREG-2150, ``A Proposed Risk Management 
Regulatory Framework.'' The staff stated that:

    Although the staff believes that the draft final 10 CFR 50.46a 
rule is an appropriate and well-founded approach to risk-inform the 
NRC's emergency core cooling requirements, the staff requests that 
SECY-10-0161 be withdrawn from Commission consideration so that it 
may be resubmitted later after the staff has completed its 
regulatory framework evaluation. When the staff establishes its 
recommended approach, it will re-evaluate the draft final 10 CFR 
50.46a rule to ensure its compatibility with the recommended 
regulatory framework. Based on the outcome of the compatibility 
evaluation and the completion of any necessary changes, the staff 
will re-submit the draft final 10 CFR 50.46a rule with or shortly 
after providing its regulatory framework recommendation to the 

    \1\ Email dated April 20, 2012 from G. Bowman requesting 
withdrawal of 10 CFR 50.46a final rule (ADAMS Accession No. 

    In SECY-16-0009, ``Recommendations Resulting from the Integrated 
Prioritization and Re-Baselining of Agency Activities'' (ADAMS 
Accession No. ML16028A189) dated January 31, 2016, the NRC staff 
requested Commission approval of work to be shed, deprioritized, or 
performed with fewer resources. One of the items to be discontinued was 
the risk-informed loss-of-coolant accident rulemaking (Item 1 of 
Enclosure 1 to SECY-16-0009).
    This rule would have provided a voluntary alternative to current 
regulatory requirements. However, at a public meeting to discuss the 
Risk Management Regulatory Framework paper (ADAMS Accession No. 
ML15026A328), certain industry representatives indicated that the 
nuclear industry would not be interested in implementing the final 
rule. The NRC staff's regulatory analysis for the draft final rule 
(ADAMS Accession No. ML103230250) also discussed comments submitted by 
the Boiling Water Reactor Owners Group, which conveyed the view that it 
would be difficult to evaluate the cost-benefit of the rule due to 
uncertainties about the cost of adopting the rule.
    The Commission approved the discontinuation of the rulemaking in 
the staff requirements memorandum (SRM) to SECY-16-0009. On October 6, 
2016, the NRC published a notice in the Federal Register informing the 
public of its decision to discontinue the 10 CFR 50.46a ECCS 
rulemaking. The NRC stated that it had ``decided not to proceed with 
this rulemaking activity because there is minimal adverse impact on our 
mission, principles, or values and the industry has indicated that 
there may not be much interest in implementing the final rule'' (81 FR 

B. Denial of PRM-50-75

    Under 10 CFR 2.803(i)(2), after closing the docket for a PRM under 
Sec.  2.803(h)(2)(ii) by addressing it in an ongoing rulemaking, if the 
NRC decides not to complete the rulemaking, the PRM is documented as 
denied. In SRM-SECY-16-0009, the Commission approved discontinuation of 
the risk-informed LOCA requirements rulemaking, which was the 
rulemaking identified to address PRM-50-75. Therefore, the NRC is 
denying PRM-50-75 without prejudice.

III. Conclusion

    The NRC previously discontinued the risk-informed LOCA requirements 
rulemaking and is therefore denying without prejudice PRM-50-75 for the 
reasons discussed in this document.

    Dated: December 8, 2020.

    For the Nuclear Regulatory Commission.
Annette L. Vietti-Cook,
Secretary of the Commission.
[FR Doc. 2020-27364 Filed 12-16-20; 8:45 am]