The AISC Load and Resistance Factor Design (LRFD) Specification for Safety-Related Steel Structures for Nuclear Facilities addresses the design, fabrication, and erection of steel safety-related structures for nuclear facilities. This document supplements the AISC Load and Resistance Factor Design Specification for Structural Steel Buildings dated December 27, 1999. It also provides an alternate method of design to that given in the ANSI/AISC N690-1994, Specification for the Design, Fabrication, and Erection of Safety-Related Steel Structures for Nuclear Facilities, including Supplement No. 1, which is based on allowable stress design.
Safety-related steel structures in nuclear facilities, which provide support and protective functions to equipment vital to the facility, are subjected to certain unique design forces and loads resulting from postulated accidents (such as turbine generated missiles and jet forces from high energy line breaks) and from extreme natural phenomena (tornadoes and earthquakes). The relevant regulatory and jurisdictional authorities (e.g. the Nuclear Regulatory Commission, the Department of Energy) dictate special quality assurance requirements and additional design requirements associated with these structures. As such, safety related nuclear structures require special LRFD design provisions. The provisions specified herein are to be used in conjunction with the AISC LRFD Specification for Structural Steel Buildings. This Specification consists of modifications (additions, deletions and replacements) of the 1999 AISC Load and Resistance Factor Design Specification for Structural Steel Buildings, referred to as the AISC LRFD Specification.
This Specification contains Load and Resistance Factor Design (LRFD) criteria for the design, fabrication, and erection of steel safety-related structures and structural elements for nuclear facilities. It is intended to be compatible with, and a supplement to, the 1999 AISC Load and Resistance Factor Design Specification for Structural Steel Buildings hereafter referred to as the AISC LRFD Specification.
Unless stated otherwise, provisions of the AISC LRFD Specification are applicable. Only those sections that differ from the AISC LRFD Specification provisions are stated within this Specification. Section designations within this Specification are preceded by the letter N to denote nuclear facility design provisions.
This specification includes the list of additional symbols, the glossary of additional definitions, and the appendices.
Additional provisions for stainless steel sections are provided in Section NA5.3. Specifically excluded from this Specification are pressure retaining components, e.g., pressure vessels, valves, pumps, and piping.
In the design of members and connections of Seismic Force Resisting Systems, the AISC Seismic Provisions for Structural Steel Buildings, in general, are not applicable. However, the detailing requirements of Sections 6 and 7 of the provisions shall be appropriately considered when designing
for plastic analysis.
Single angle members shall comply with the Load and Resistance Factor Design Specification for Single-Angle Members and with this Specification. Hollow structural sections (HSS) shall comply with the Load and Resistance Factor Design Specification for Steel Hollow Structural Sections
and with this Specification.
The sponsors of any system or construction within the scope of this Specification, the adequacy of which has been shown by successful use or by analysis or test, but which does not conform to or is not covered by this specification, shall have the right to present the data on which their design is based to the authority having jurisdiction for review and approval. Structures and structural elements subject to this Specification are those steel structures which are parts of a safety-related system or which support, house, or protect safety-related systems or components, the failure of which would impair the safety-related functions of these systems or components. Safety categorization for nuclear facility steel structures and structural elements shall be the responsibility of the owner.
As used in this Specification, the term structural steel refers to the steel elements of the structural steel frame essential to the support of the required loads. Such elements are enumerated in Section 2.1 of the AISC Code of Standard Practice for Steel Buildings and Bridges. For the design of cold-formed steel structural members, whose profiles contain rounded corners and slender flat elements, the provisions of the American Iron and Steel Institute North American Specification for the Design of Cold-Formed Steel Structural Members shall be applicable.
