No description at the National Archives. Castle Films produced this film for the U.S. military -- "Operation Crossroads" US Army film # MISC-1323 and US Navy film # MN 5345. Description from Armed Forces Films for Public and Television Use: "A documentary of the Able and Baker blasts of the Atomic Bomb Test at Bikini, produced by Joint Army-Navy Task Force One."
National Archives Identifier: 88210 source file isn't in the greatest shape.

No description at National Archives but listed in AEC 16mm film combined catalog (1966): "BIKINI RADIQBIOLOGICAL LABORATORY (1949). 22 minutes, color. 
Produced by the University of Washington and the USAEC. For  sale by Lookout Mountain Air Force Station, USAF, at $92.00  per print from master, including shipping case.