Backfitting Guidelines - Draft Report for Comment (NUREG-1409, Revision 1)

This NUREG-series publication was issued for public comment. The comment period is now closed.

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Publication Information

Manuscript Completed: March 2020
Date Published: March 2020


Prepared by:
H. Benowitz
A. Klett
T. Reed

Office of Nuclear Reactor Regulation
U.S. Nuclear Regulatory Commission
Division of Operating Reactor Licensing
Washington, DC 20555-0001

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NUREG–1409, "Backfitting Guidelines," Revision 1, provides guidance to the U.S. Nuclear Regulatory Commission (NRC) staff on the implementation of the backfitting and issue finality provisions in Title 10 of the Code of Federal Regulations (10 CFR) Chapter I and the backfitting, issue finality, and forward fitting policies provided in Management Directive 8.4, "Management of Backfitting, Forward Fitting, Issue Finality, and Information Requests," dated September 20, 2019.


Backfitting occurs when the NRC imposes new or changed regulatory requirements or staff interpretations of the regulations or requirements on nuclear power reactor licensees, certain nuclear power reactor applicants, or select nuclear materials licensees. Backfitting is an integral part of the regulatory process and may be needed when the staff addresses safety or security issues. The NRC may take a backfitting action only after conducting a formal, systematic review to ensure that the action is defined and justified. This process ensures discipline, predictability, and optimal use of NRC and licensee resources. The backfitting requirements are in 10 CFR 50.109, "Backfitting," 70.76, "Backfitting," 72.62, "Backfitting," and 76.76, "Backfitting." Provisions analogous to the backfitting requirements, referred to as issue finality provisions, are set forth in 10 CFR Part 52, "Licenses, Certifications, and Approvals for Nuclear Power Plants."

Forward fitting occurs when the NRC conditions its approval of a licensee–initiated request for a licensing action on the licensee's compliance with a new or modified requirement or staff interpretation of a requirement that the licensee did not request. The new or modified requirement or staff interpretation must result in, generally, a change to the licensee's systems, structures, components, design, approval, procedures, or organization.

The NRC issued the previous version of this NUREG in 1990, but the 1990 document did not address the backfitting requirements in 10 CFR Part 70, "Domestic Licensing of Special Nuclear Material," 10 CFR Part 72, "Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High–Level Radioactive Waste, and Reactor–Related Greater Than Class C Waste," or 10 CFR Part 76, "Certification of Gaseous Diffusion Plants"; the issue finality provisions in 10 CFR Part 52; or the Commission's forward fitting policy in Management Directive 8.4, most of which were developed after 1990. This version of NUREG–1409 is a substantial revision of the 1990 version and addresses all backfitting and issue finality provisions in the regulations listed above and the Commission's backfitting, issue finality, and forward fitting policies.

Page Last Reviewed/Updated Wednesday, March 24, 2021