Nuclear Air Cleaning Codes and Standards Development and Use in the United States

The need to provide standardized guidance for the use of air cleaning systems in nuclear facilities was recognized in the 1960’s when plans for nuclear facilities were at their peak. The American National Standards Institute (ANSI) asked a group of experts to generate documents for boiling-water-reactor standby gas treatment systems for accident mitigation. These experts immediately recognized that their scope needed expansion to include all air cleaning safety systems at all types of nuclear facilities. Their efforts resulted in the issuance of documents that provided guidance for the components in air cleaning systems (ANSI N509), and guidance for the testing of these systems (ANSI N510). Subsequently, it was recognized that this guidance needed to be formalized and implemented in a code format, with requirements instead of recommendations. Various other organizations were also providing guidance in different forms. The US government (the Nuclear Regulatory Commission) issued regulatory guides, and the American Society for Testing of Materials (ASTM) issued many documents providing specifications for activated carbon used in air cleaning systems for radioiodine removal. Acknowledging the need to consolidate all of these documents in a single source, the American Society for Mechanical Engineers (ASME) requested the air cleaning experts to work on publishing a code section under ASME auspices. This code section, designated AG-1, was assigned to a newly formed committee, the ASME Committee on Nuclear Air and Gas Treatment (CONAGT). This Committee started work in the mid 1970’s, and has issued various sections of the code since then, and the document now totals 600 pages. This code section covers the design, construction, installation, operation and testing of air cleaning systems in nuclear facilities. Work continues on updates to these sections of the AG-1 Code, as well as new sections specifically addressing gas processing systems. ASME code section AG-1 is the main international document for nuclear air cleaning systems for safe operation of nuclear power facilities, to ensure the safety of workers, and to protect public health and safety and the environment. The Code has four divisions, and a membership of over 100 of the premier air cleaning experts from 11 different countries.