Elaboration of the System Based Code Concept — Activities in JSME and ASME: (1) Overview

This paper is the first one of the series of four papers that describe ongoing activities in the Japan Society of Mechanical Engineers (JSME) and the American Society of Mechanical Engineers (ASME) on the elaboration of the System Based Code (SBC) concept aiming at its application to nuclear structural codes and standards. This paper includes a brief introduction to the SBC concept and the technical features of structural evaluation methodologies that are being developed for use in the SBC concept; Load and Resistance Factor Design based reliability assessment methods and the JSME guidelines for reliability evaluation of static components of sodium-cooled fast reactors. Also described is the ongoing collaboration of JSME and ASME at the Joint Task Group for System Based Code established in the ASME Boiler and Pressure Vessel Code Committee which is developing alternative rules for ASME B&PV Code Section XI Division 3, inservice inspection requirements for liquid metal reactor components.

Liquid Metal Reactor Regulatory Framework Assessment

This paper summarizes an assessment of the regulatory framework and requirements for licensing a liquid metal reactor (LMR) for use in transmuting actinides, which was performed for the U.S. Department of Energy (DOE) Advanced Fuel Cycle Initiative (AFCI). Since the LMR designs currently under consideration are sodium-cooled, the assessment identifies and discusses requirements, issues, and topics important to the licensing process in general and those specific to sodium-cooled LMRs, as well as licensing options and associated recommendations. The goal of the regulatory framework assessment was to clarify and evaluate requirements that support the development of safe and cost-effective LMR designs. The scope of the assessment included an analysis of past and present licensing practices as well as an examination of possible future regulatory activities needed to support licensing LMR designs. Because this assessment included the identification of potentially problematic areas, a review of the past LMR licensing efforts was performed. Both technical and regulatory issues were identified and recommendations were made to address important issues. A review of the current regulatory framework for licensing a commercial reactor and the associated licensing schedules was performed as part of the assessment. In addition, specific options proposed by the U.S. Nuclear Regulatory Commission (NRC) for licensing an LMR were also assessed with regard to their potential impacts on different stakeholders, which include the NRC, DOE, industry, and the public. In addition to the licensing of a commercial LMR, the assessment also identifies and evaluates licensing options for an LMR prototype. The regulatory assessment supports a conclusion that a safe, licensable LMR design is fully feasible. The knowledge applied in the LMR design will be reinforced by past experience and available technology. The licensing of an LMR is expected to be manageable, notwithstanding the uncertainties associated with regulatory, technical, and other issues. With forward-looking planning, effective management, and adequate resources, the process of obtaining a license for an LMR would be greatly facilitated.