The U.S. Nuclear Regulatory Commission (NRC) is amending its regulations that govern the NRC's environmental reviews of new nuclear reactor applications under the National Environmental Policy Act. The rulemaking codifies the generic findings of the NRC's Generic Environmental Impact Statement for Licensing of New Nuclear Reactors. The Generic Environmental Impact Statement for Licensing of New Nuclear Reactors uses a technology-neutral framework and a set of plant and site parameters to determine which potential environmental impacts would be common to the construction, operation, and decommissioning of many new nuclear reactors, and thus appropriate for a generic analysis, and which potential environmental impacts would be unique, and thus require a project-specific analysis. The NRC is also issuing revision 4 to regulatory guide 4.2, "Preparation of Environmental Reports for Nuclear Power Stations," and COL-ISG-030, "Environmental Considerations Associated with New Nuclear Reactor Applications that Reference the Generic Environmental Impact Statement (NUREG-2249)." This rulemaking is separate from NRC's comprehensive review and reform of its regulations, including those governing environmental review, in accordance with Executive Order (E.O.) 14300, "Ordering the Reform of the Nuclear Regulatory Commission."