This rule would amend the NRC's physical security requirements for small modular reactors and other advanced reactor technologies. This rulemaking would establish voluntary alternative physical security requirements commensurate with the potential consequences to public health and safety and the common defense and security. This rulemaking would provide regulatory stability, predictability, and clarity in the licensing process and minimize or eliminate uncertainty for applicants who might otherwise request exemptions from the regulations. The NRC engaged with stakeholders by holding public meetings; issuing draft versions of preliminary proposed rule language; and requesting public feedback.