Modernize Nuclear Reactor Environmental Reviews Act This bill directs the Nuclear Regulatory Commission to submit to Congress a report on facilitating efficient, timely environmental reviews of nuclear reactors through expanded use of categorical exclusions, environmental assessments, and generic environmental impact statements. The commission must promulgate a final rule to (1) establish an optical generic environmental impact statement for actions relating to nuclear reactors that may be used in the process for issuing a construction permit, early site permit, or combined license; and (2) amend criteria for and identification of licensing and regulatory actions to eliminate the list of actions that require environmental impact statements to allow for the use of environmental assessments and categorical exclusions for such actions.