6 U.S. Code § 321f - Nuclear incident response
(a) In general
At the direction of the Secretary (in connection with an actual or threatened terrorist attack, major disaster, or other emergency in the United States), the Nuclear Incident Response Team shall operate as an organizational unit of the Department. While so operating, the Nuclear Incident Response Team shall be subject to the direction, authority, and control of the Secretary.
(b) Rule of construction
Nothing in this subchapter shall be construed to limit the ordinary responsibility of the Secretary of Energy and the Administrator of the Environmental Protection Agency for organizing, training, equipping, and utilizing their respective entities in the Nuclear Incident Response Team, or (subject to the provisions of this subchapter) from exercising direction, authority, and control over them when they are not operating as a unit of the Department.