Classification schemes for equipment used in nuclear power generating stations

During the past several years, considerable momentum has been achieved in the development of standards, codes and guides for application to equipment in nuclear power generating stations. Common to all of this work is a number of "classification schemes" to identify the types or functions of equipment to which the various standards apply. The parent organizations responsible for preparing the standards represent a number of different disciplines and philosophical backgrounds, with the result that the equipment definitions and the various classification schemes are diverse and in some cases they overlap. The purpose of this paper is to review the variety of classification schemes which are encountered in the regulatory process and in the standards writing groups for nuclear power generating stations, and to summarize the efforts of the American Nuclear Society BWR Criteria Subcommittee pertaining to equipment classification and design requirements for boiling water reactors.