Japan intended to built a nuclear propelled container ship according to the Dutch newspaper Het vrije volk dated 30 January 1967

Van Stoom tot Atoom, 1961
Text G.A.J. Bovens-drawings G.J. Frans Naerebout

An item reported that despite the commercial failure with the American nuclear cargo ship Savannah (1) the Japanese government atomic energy commission announced the intended building of a nuclear propelled containership with a speed of nearly 50 kilometres. It would be the second Japanese nuclear merchant ship.(2)

Notes
1. First American nuclear merchant ship was the Savannah, building ordered in 1955, launched by New York Shipbuilding Corporation, Camden, New Jersey, USA with yard number 529 on 21 July 1959, completed in December 1961, maiden voyage begun on 20 August 1962 and decommissioned on 10 January 1972. IMO 5314793, cal sign KSAV.
2. Japan built just one nuclear ship namely cargo ship Mutsu, laid down by Second Tokyo Factory, Ishikawajima-Harima Hvy Ind on 17 November 1968, launched on 12 June 1970, delivered on 13 July 1970, completed and fully loaded on 4 September 1972, decommissioned 1992 and rebuilt as the still existing research vessel Mirai. IMO 6919423