Modernize Nuclear Reactor Environmental Reviews Act This bill directs the Nuclear Regulatory Commission to report on its efforts to facilitate efficient, timely environmental reviews of nuclear reactors through expanded use of categorical exclusions, environmental assessments, and generic environmental impact statements in lieu of environmental impact statements as required under the National Environmental Policy Act of 1969. The commission must promulgate a final rule to (1) establish an optional generic environmental impact statement that may be used in the licensing process for nuclear reactors, and (2) eliminate or modify the list of actions that require environmental impact statements.