A Guide for the ASME Code for Austenitic Stainless Steel Containment Vessels for High-Level Radioactive Materials*

The design and fabrication criteria recommended by the U.S. Department of Energy (DOE), Office of Facility Safety Analysis, for containment vessels of Type B commercial packagings containing high-level radioactive materials are found in Section III, Division 1, Subsection NB of the ASME Boiler and Pressure Vessel Code (DOE 1985 and NRC 1994). This Code provides specifications for material, design, fabrication, examination, and testing of nuclear power plant components. However, many of the requirements listed in the Code are not applicable to containment vessels made from austenitic stainless steel with austenitic- or ferritic-steel bolting. Most packaging designers, engineers, and fabrica•ors are intimidated by the sheer volume of requirements contained in the Code; consequently, the Code is not always followed and many requirements that do apply are often overlooked during preparation of the Safety Analysis Report for Packaging (SARP) that constitutes the basis for evaluating the packaging for certification. The purpose of this guide is to provide a list of ASME Code paragraphs from Section III, Division 1, Subsection NB (ASME 1992) that are applicable to the design, fabrication, examination, and testing of containment vessels for high-level radioactive materials. Because of the high level of radioactivity in these vessels, they are defined as Category I containment vessels (DOE 1988). The guide is also intended to provide guidance for including the appropriate Code requirements when preparing a SARP, construction drawings, and specifications for materials, fabrication, and examination of Category I containment vessels. In addition, the guide lists DOE positions related to certain Code requirements that may be ambiguous with respect to the design and fabrication of Category I containment vessels that are used for transport.