ANS 2.27

Abstract

This standard provides criteria and guidelines for conducting geological, seismological, and geotechnical investigations needed to provide information to support the following: <br>(1)Seismic source characterization input to a probabilistic seismic hazard analysis (PSHA); <br>(2) evaluation of surface fault rupture hazard; <br>(3) site response analysis; <br>(4) seismic-induced ground failure hazard. <br>These criteria are applicable for Seismic Design Category (DC)3, SDC-4, and SDC-5 structures, systems, or components (SCs). <br>This standard does not address the use of PSHA results or the selection of design-basis events for nuclear facilities. These topics are covered in American National Standards Institute/American Nuclear Society ANSI/ANS- 2.26-2004, "Categorization of Nuclear Facility Structures, Systems, and Components for Seismic Design" [1]¹⁾ and American Society of Civil Engineers/Structural Engineering Institute ASCE/SEI 43-05, "Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities" [2]. <br>This standard is one of a series of national standards designed to provide criteria and guidelines to promote uniform and effective assessment of seismic hazards at nuclear facilities. These hazards must be properly identified and characterized commensurate with the level of risk and design requirements associated with each nuclear facility as specified in ANSI/ANS-2.26-2004 [1] and ASCE0 SEI 43-05 [2]. As defined in ANSI/ANS-2.26- 2004 [1], a nuclear facility is a facility that stores, processes, tests, or fabricates radioactive materials in such form and quantity that a nuclear risk to the workers, to the off-site public, or to the environment may exist. These include, but are not limited to, nuclear fuel manufacturing facilities; nuclear material waste processing, storage, fabrication, and reprocessing facilities; uranium enrichment facilities; tritium production and handling facilities; and radioactive materials laboratories. Additional criteria may be specified by the applicable regulatory authority. <br>This standard outlines standard criteria and procedures to collect data needed as input to probabilistic analysis of seismic hazards at nuclear facilities as specified in ANSI/ANS- 2.29-2008, "Probabilistic Seismic Hazards Analysis" [3]. Appropriate approaches are outlined to ensure that the current state-of-the art methodology is being used in the site characterization. The selection of specific techniques and level of detail required to assess seismic and seismic-induced hazards is dependent on both the nature of the nuclear facility (i.e., SDC²⁾ as defined by ANSI/ANS- 2.26-2004 [1]) and site-specific conditions.³⁾ <br>1) Numbers in brackets refer to corresponding numbers in Sec. 5, "References." <br>2) The SDCs used in this standard are not the same as the SDCs referred to in the International Building Code (IBC). <br>3) In this standard, material that is double-indented indicates a commentary.