Caldwell, selected for a fourth star and appointment to the rank of admiral, would succeed Adm. John Richardson as the 7th director of naval reactors.
Richardson has been nominated to become the next chief of naval operations (CNO), succeeding retiring Adm. Jon Greenert. Richardson has yet to be confirmed in the new post pending a Senate Armed Services Committee confirmation hearing tentatively scheduled for the first week of August.
The NR billet is unique in the Navy, with an eight-year tour of duty. Richardson, who assumed the NR job in November 2012, would become the first admiral to leave before completing a full eight-year term since 1988.
The NR job is one of the most powerful positions in the US military, and is dual-hatted with the Department of Energy. The position was established in 1949 by Hyman Rickover, who fought off numerous attempts to replace him by skillfully balancing his military and civilian responsibilities. Rickover was finally retired in February 1982 by President Ronald Reagan after serving 33 years in the position.
Since Rickover, submariners have traditionally held the NR position. All US Navy submarines are nuclear-powered, as are all of the fleet's aircraft carriers.
Caldwell is currently serving as director of the Navy Staff, reporting directly to the CNO, but has held the position only since May. Before that, he served as the Navy's inspector general.
According to his official biography, Caldwell graduated with distinction in 1981 from the US Naval Academy with a Bachelor of Science degree in marine engineering. He also holds a Master of Science in Operations Research from the Naval Postgraduate School. He entered the submarine service and completed tours in both the Atlantic and Pacific fleets, commanding the fast attack submarine USS Jacksonville, Submarine Development Squadron 12 in New London, Connecticut; Submarine Group 9 in Bangor, Washington; and the Submarine Force, US Pacific Fleet, Hawaii.
Ashore, Caldwell served on the Pacific Fleet Nuclear Propulsion Examining Board and later as Undersea Warfare Requirements officer on the staff of Commander in Chief, US Pacific Fleet. He also served as senior member of the Naval Submarine Force's Tactical Readiness Evaluation Team; on the Joint Staff as deputy director for Politico-Military Affairs for Europe, the North Atlantic Treaty Organization, Russia and Africa; and deputy commander for U.S. Strategic Command's Joint Functional Component Command for Global Strike in Omaha, Nebraska.