AISC - N690
Specification for Safety-Related Steel Structures for Nuclear Facilities
|Publication Date:||28 June 2018|
The Specification for Safety-Related Steel Structures in Nuclear Facilities, hereafter referred to as the Nuclear Specification, shall apply to the design of safety-related steel structures and steel elements in nuclear facilities.
The Chapter, Appendix and Section designations within the Nuclear Specification are preceded by letter N to denote nuclear facility provisions.
The Nuclear Specification is compatible with the AISC Specification for Structural Steel Buildings (ANSI/AISC 360), hereafter referred to as the Specification. Provisions of the Specification are applicable unless stated otherwise. Only those sections that differ from the Specification provisions are indicated in the Nuclear Specification.
The Nuclear Specification includes the list of additional Symbols, additional Glossary terms, Chapters NA through NN, and Appendices N1 through N9. The Commentary and User Notes interspersed throughout the Nuclear Specification are not part of the Nuclear Specification. The phrases "is permitted" and "are permitted" in this document identify provisions that comply with the Nuclear Specification, but are not mandatory.
User Note: User notes are intended to provide concise and practical guidance in the application of the provisions.
The steel elements shall be as defined in the AISC Code of Standard Practice for Steel Buildings and Bridges (ANSI/AISC 303), Section 2.1, hereafter referred to as the Code of Standard Practice.
Structures and structural elements subject to the Nuclear Specification are those steel structures and structural elements that are part of a safety-related system or that support, house or protect safety-related systems or components, the failure of which could credibly result in the loss of capability of the structure, system or component to perform its safety functions. Concrete that is part of steel-plate composite (SC) walls is also subject to the Nuclear Specification. Safety categorization for nuclear facility steel structures and structural elements shall be the responsibility of the owner and shall be identified in the contract documents.
Specifically excluded from the Nuclear Specification are the pressure-retaining components, including but not limited to pressure vessels, valves, pumps and piping.
When designing for inelastic behavior such as that caused by impact loads, the design shall follow the material requirements of Section A3 of the AISC Seismic Provisions for Structural Steel Buildings (ANSI/AISC 341), hereafter referred to as the Seismic Provisions, and the general member and connection requirements of Seismic Provisions Sections D1 and D2 for highly ductile members, respectively.
For a structural system or construction within the scope of the Nuclear Specification where conditions are not covered by the Nuclear Specification, it is permitted to base the adequacy of the designs on tests, analysis or successful use, subject to the approval of the authority having jurisdiction.
User Note: With the exception of hollow structural sections (HSS), for the design of structural members that are cold-formed to shapes with elements not more than 1 in. (25 mm) in thickness, the use of provisions of the AISI North American Specification for the Design of Cold-Formed Steel Structural Members is recommended, incorporating the loads and load combinations delineated in Section NB2 of the Nuclear Specification.