scope:

This standard provides requirements for using RIPB methods to support (1) definition of safety requirements; (2) licensing-basis event (LBE) selection; (3) design-basis safety analysis; (4) probabilistic risk assessments (PRAs); (5) severe accident analysis; (6) classification and categorization of structures, systems, and components (SSCs); (7) systematic defense-in-depth (DID) evaluations; and (8) performance-based decision analysis.

The plant designer is responsible for selecting and implementing specific design requirements necessary for implementation of this standard, including support for defining accidents and expected operational characteristics through design analyses, models, conformance with applicable industrial codes and standards, or experience gained from similar designs. The designer is also responsible for the use of alternate or additional criteria and requirements to accommodate unique technologies, designs, or site characteristics not covered (or referenced) by this standard or its related documents. The inclusion of RIPB practices also supports a greater understanding of uncertainties surrounding deterministic safety evaluations and establishing compensatory actions for risk-significant uncertainties.

Purpose

This standard¹⁾ provides requirements for the incorporation of risk-informed, performance-based (RIPB) principles and methods into the nuclear safety design of new commercial light water reactors (LWRs). The process described herein establishes a minimum set of requirements for the designer to follow in order to appropriately combine deterministic, probabilistic, and performance-based methods during design development.

¹⁾ The current standard, ANSI/ANS-30.3-2022, is hereinafter referred to as "this standard."