WOW another little know fact!

[I-25]

Lookie what i found...

Old Japanese army tests A-bomb in sea off Korea

Pyongyang, August 8 (KCNA) -- The Japanese Tokyo Shimbun August 6 disclosed that the old Japanese army tested an A-bomb in the sea off Hungnam on the east coast of Korea just before the end of World War II. According to a secret document of the U.S. Army quoting the Jiji news from the U.S. National Archives, the U.S. Army was informed of the fact that a test related to the atomic power took place at a chemical factory in Hungnam in 1945 and ordered investigation into it. It also said in an investigation report worked out on January 16, 1947, that the Japanese army made an explosion test with the help of a boat in waters off the east coast of the North Korea, the result of which was like an A-bomb.
The U.S. forces received information from an intelligence officer of the old Japanese army that it tested an A-bomb in waters 30 km away from Hungnam at the dawn of August 12, 1945, and huge mushroom-like clouds rose at that time. Tokyo Shimbun said that Japan began an A-bomb research in secrecy on the order of the army headquarters from about 1940.

http://www.kimsoft.com/korea/jp-hung.htm