Overview of ASCE 4 Rev. 2

ASCE 4, Seismic Analysis of Safety-Related Nuclear Structures and Commentary , was first issued in 1986. It was expanded, revised and re-issued in 1998. The second revision of the standard will soon be completed by the Working Group on Revision of ASCE 4, which is part of the ASCE Committee for Dynamic Analysis of Nuclear Structures. This standard provides prescriptive criteria for the analysis of safety-related (Seismic Category I ) structures, systems and components (SSCs). It is designed to be used in conjunction with ASCE-43/SEI 43-05, Seismic Design Criteria for Structures, Systems and Components in Nuclear Facilities. It addresses all aspects of seismic analysis: site response, modeling, and analysis for all types of SSCs. The standard also provides guidance on Quality Assurance requirements and Peer Review needs. Taken together, ASCE4 and ASCE/SEI43-05 may be adapted by federal agencies such as the U.S. Nuclear Regulatory Commission and the U.S. Department of Energy as the minimum expected seismic analysis and design requirements for nuclear facilities. This overview paper highlights the proposed changes to the ASCE 4-98 Standard proposed by the Working Group. These changes, if adapted, will become effective following consensus balloting and public comment of the proposed changes.