Editorial Note on Part 51
Editorial Note: Nomenclature changes to part 51 appear at 80 FR 74980, Dec. 1, 2015.

§ 51.4 Definitions. As used in this part: *Act* means the Atomic Energy Act of 1954 (Pub. L. 83-703, 68 Stat. 919) including any amendments thereto.
*Commission* means the Nuclear Regulatory Commission or its authorized representatives.
*Construction* means: ( 1 ) For production and utilization facilities, the activities in paragraph (1)(i) of this definition, and does not mean the activities in paragraph (1)(ii) of this definition. ( i ) Activities constituting construction are the driving of piles, subsurface preparation, placement of backfill, concrete, or permanent retaining walls within an excavation, installation of foundations, or in-place assembly, erection, fabrication, or testing, which are for: ( A ) Safety-related structures, systems, or components (SSCs) of a facility, as defined in 10 CFR 50.2;
( B ) SSCs relied upon to mitigate accidents or transients or used in plant emergency operating procedures;
( C ) SSCs whose failure could prevent safety-related SSCs from fulfilling their safety-related function;
( D ) SSCs whose failure could cause a reactor scram or actuation of a safety-related system;
( E ) SSCs necessary to comply with 10 CFR part 73;
( F ) SSCs necessary to comply with 10 CFR 50.48 and criterion 3 of 10 CFR part 50, appendix A; and
( G ) Onsite emergency facilities (*i.e.,* technical support and operations support centers), necessary to comply with 10 CFR 50.47 and 10 CFR part 50, appendix E.
( ii ) Construction does not include: ( A ) Changes for temporary use of the land for public recreational purposes;
( B ) Site exploration, including necessary borings to determine foundation conditions or other preconstruction monitoring to establish background information related to the suitability of the site, the environmental impacts of construction or operation, or the protection of environmental values;
( C ) Preparation of a site for construction of a facility, including clearing of the site, grading, installation of drainage, erosion and other environmental mitigation measures, and construction of temporary roads and borrow areas;
( D ) Erection of fences and other access control measures that are not safety or security related, and do not pertain to radiological controls;
( E ) Excavation;
( F ) Erection of support buildings (e.g., construction equipment storage sheds, warehouse and shop facilities, utilities, concrete mixing plants, docking and unloading facilities, and office buildings) for use in connection with the construction of the facility;
( G ) Building of service facilities (e.g., paved roads, parking lots, railroad spurs, exterior utility and lighting systems, potable water systems, sanitary sewerage treatment facilities, and transmission lines);
( H ) Procurement or fabrication of components or portions of the proposed facility occurring at other than the final, in-place location at the facility;
( I ) Manufacture of a nuclear power reactor under a manufacturing license under subpart F of part 52 of this chapter to be installed at the proposed site and to be part of the proposed facility; or
( J ) With respect to production or utilization facilities, other than testing facilities and nuclear power plants, required to be licensed under section 104.a or section 104.c of the Act, the erection of buildings which will be used for activities other than operation of a facility and which may also be used to house a facility (e.g., the construction of a college laboratory building with space for installation of a training reactor).
( 2 ) For materials licenses, taking any site-preparation activity at the site of a facility subject to the regulations in 10 CFR parts 30, 36, 40, and 70 that has a reasonable nexus to radiological health and safety or the common defense and security; provided, however, that construction does not mean: ( i ) Those actions or activities listed in paragraphs (1)(ii)(A)-(H) of this definition; or
( ii ) Taking any other action that has no reasonable nexus to radiological health and safety or the common defense and security.
*NRC* means the Nuclear Regulatory Commission, the agency established by Title II of the Energy Reorganization Act of 1974, as amended.
*NRC staff* means any NRC officer or employee or his/her authorized representative, except a Commissioner, a member of a Commissioner's immediate staff, an Atomic Safety and Licensing Board, a presiding officer, an administrative judge, an administrative law judge, or any other officer or employee of the Commission who performs adjudicatory functions.
*NRC staff director* means the Executive Director for Operations; the Director, Office of Nuclear Reactor Regulation; the Director, Office of Nuclear Material Safety and Safeguards; the Director, Office of Nuclear Regulatory Research; the Director, Office of Public Affairs; and the designee of any NRC staff director.
[49 FR 9381, Mar. 12, 1984, as amended at 51 FR 35999, Oct. 8, 1986; 52 FR 31612, Aug. 21, 1987; 72 FR 57443, Oct. 9, 2007; 73 FR 5723, Jan. 31, 2008; 76 FR 56964, Sept. 15, 2011; 77 FR 46599, Aug. 3, 2012; 79 FR 75740, Dec. 19, 2014; 84 FR 65644, Nov. 29, 2019; 87 FR 68031, Nov. 14, 2022]