NRC's Regional Office in King of Prussia (Region I) is responsible for carrying out the agency's duties in Washington, DC. No operating nuclear reactors or fuel cycle facilities are located in Washington, DC. Washington, DC is not an Agreement State. The District has jurisdiction over x-ray equipment, naturally occurring radioactive materials, and certain radioactive materials that are not produced in a reactor.
More information about Washington DC's role in ensuring the safe use of radioactive materials can be obtained from the NRC Office of State Program's Directory of State Regulations, Legislation, and Web Sites.
Operating Nuclear Power Reactors