Uploaded January 2024 | Updated September 2026, 2 weeks ago
This is a tape-recording of a press conference given by Tatsusaburo Suzuki, the physicist who initiated Japan's atomic bomb program during WWII. He wrote a report in 1940 saying an atomic bomb was feasible, and recommended its construction. He became the army liaison with the research team.
He was the only member of the team to speak publicly about the program, and he only did so once, at a press conference in 1995.
The only recording of that press conference is on an old cassette tape at the Foreign Correspondents' Club of Japan (FCCJ), so when I was in Tokyo a few years ago I made a digital copy for posterity. I am posting it here, to make it available to scholars, historians and anyone else who wants to research the history of the bomb.
The background and summary in this video are based on that press conference, which I attended as a correspondent for New Scientist magazine. But please note an important correction: Suzuki did not, in fact, say that they had succeed in U235-U238 separation 'to a satisfactory degree.' He simply said they did not succeed. I am grateful to a poster, @nickpatella1525, for providing this more accurate transcript from 39:48 on the video:
そういう計算なんかは終わっておりました。We had made such calculations. しかしウラン235を分離するということには成功しておりません。However, the separation of Uranium-235 we did not succeed in. これは二つの方法を日本でやりました。In Japan, we did this with two methods. 一つは、thermal diffusion、熱拡散の方法。The first was the method of thermal diffusion. それからもう一つは遠心分離の方法、centrifugal forceを使った方法。The other was the method of centrifugal separation, a method using centrifugal force. で、えぇ、熱拡散の方法につきましては、予備実験は成功しています。And, uh, so with regards to the method of thermal diffusion, we succeeded in preparatory experiments. 予備実験というのは、例えば窒素とか、あるいは二酸化炭素の同位元素を分離する、そういうことには成功しておりますが、ウランの分離には成功しておりません。 What I mean by preparatory experiments is, for example, the separation of nitrogen or carbon dioxide isotopes, we succeeded in such things as that, but we did not succeed in the separation of uranium.
Other sources are Japanese historians and sources close to Japanese criminal gangs, as well as books I read while stationed in Japan, including the first edition of 'Japan's Secret War' by Robert Wilcox, 'Kempeitai' by Lamont-Brown (about the Japanese Imperial Army's intelligence force). There is also a book on the Imperial Japanese Navy's intelligence force, the Tokkeitai, but decades after the event I can't remember the title, sorry. The summary and background are not as important as the press conference, where you will hear Suzuki's testimony directly.
There is a recent movie about Japan`s atom bomb research called Taiyo no ko (太陽の子.) You'll see the same account of events in a few blogs and videos, but be careful -- the blogs and videos are simply copying their info from the movie, which is largely a work of fiction.
There are also reports that Japan set off a test atomic bomb just before the end of the war, but there is very little evidence of that.
This is a tape-recording of a press conference given by Tatsusaburo Suzuki, the physicist who initiated Japan's atomic bomb program during WWII. He wrote a report in 1940 saying an atomic bomb was feasible, and recommended its construction. He became the army liaison with the research team.
He was the only member of the team to speak publicly about the program, and he only did so once, at a press conference in 1995.
The only recording of that press conference is on an old cassette tape at the Foreign Correspondents' Club of Japan (FCCJ), so when I was in Tokyo a few years ago I made a digital copy for posterity. I am posting it here, to make it available to scholars, historians and anyone else who wants to research the history of the bomb.
The background and summary in this video are based on that press conference, which I attended as a correspondent for New Scientist magazine. But please note an important correction: Suzuki did not, in fact, say that they had succeed in U235-U238 separation 'to a satisfactory degree.' He simply said they did not succeed. I am grateful to a poster, @nickpatella1525, for providing this more accurate transcript from 39:48 on the video:
そういう計算なんかは終わっておりました。We had made such calculations. しかしウラン235を分離するということには成功しておりません。However, the separation of Uranium-235 we did not succeed in. これは二つの方法を日本でやりました。In Japan, we did this with two methods. 一つは、thermal diffusion、熱拡散の方法。The first was the method of thermal diffusion. それからもう一つは遠心分離の方法、centrifugal forceを使った方法。The other was the method of centrifugal separation, a method using centrifugal force. で、えぇ、熱拡散の方法につきましては、予備実験は成功しています。And, uh, so with regards to the method of thermal diffusion, we succeeded in preparatory experiments. 予備実験というのは、例えば窒素とか、あるいは二酸化炭素の同位元素を分離する、そういうことには成功しておりますが、ウランの分離には成功しておりません。 What I mean by preparatory experiments is, for example, the separation of nitrogen or carbon dioxide isotopes, we succeeded in such things as that, but we did not succeed in the separation of uranium.
Other sources are Japanese historians and sources close to Japanese criminal gangs, as well as books I read while stationed in Japan, including the first edition of 'Japan's Secret War' by Robert Wilcox, 'Kempeitai' by Lamont-Brown (about the Japanese Imperial Army's intelligence force). There is also a book on the Imperial Japanese Navy's intelligence force, the Tokkeitai, but decades after the event I can't remember the title, sorry. The summary and background are not as important as the press conference, where you will hear Suzuki's testimony directly.
There is a recent movie about Japan`s atom bomb research called Taiyo no ko (太陽の子.) You'll see the same account of events in a few blogs and videos, but be careful -- the blogs and videos are simply copying their info from the movie, which is largely a work of fiction.
There are also reports that Japan set off a test atomic bomb just before the end of the war, but there is very little evidence of that.
