]]]]]]]]]]]]       THE JAPANESE A-BOMB        [[[[[[[[[[[[[[[[[[[[ 
          [Kindly uploaded by Freeman 10602PANC]       (9/13/1988)

Nuclear Weapons History: Japan's Wartime Bomb Projects Revealed
                      By Deborah Shapley

[This is an  abridged and slightly edited  version of the article
       appearing in Science, 13 Jan 1978, pp. 152-157]

   A little-publicized chapter  in the history  of atomic weapons
is the Japanese effort to develop an atomic bomb during World War
II.   The  effort  centered  around  Japan's  university  physics
laboratories, and  its chief figure  was Yoshio  Nishina, who was
Japan's  leading  scientist  and  a  physicist  of  international
   Much has been written about  how the United States and Britain
during  the  war  were  concerned   that  the  Germans,  who  had
discovered  atomic  fission  in  the  1930's,  would  develop the
world's  first superbomb  based on  this principle.   Indeed, the
German wartime atomic  research effort was  a major rationale for
the Manhattan Project in the United States.
   But in  the case  of Japan it  seems that  no one  in the U.S.
government took the possibility of a Japanese atomic bomb project
   Still  more  curious  is  the  curtain  of  silence  which the
Japanese themselves  seem to  have pulled  over the  subject, and
which  they have  kept  tightly drawn  since  the war.   Even the
Americans who interrogated  Nishina concluded that  Japan had had
no atomic bomb project.
   Even today in Japan, when  historians tell Japanese that there
was such a project, many  Japanese react with disbelief.  Japan's
postwar official policy, that she does not and never will seek to
be a nuclear-armed country, seems to have inhibited discussion of
the  project.  Japan's  wartime  atomic research,  in  Japan, has
become a social secret.
   The  effort  is  documented   in  two  authoritative  Japanese
histories.  One is  a history of science  and technology in Japan
of which  volume 13,  published in  1970, deals  with science and
technology during World  War II.  The second  is a social history
of  science, by  Tetu Hirosige,  published in  1973, that  has an
entire  chapter  devoted  to  the  wartime  science mobilization,
including among other  things, atomic research.   Nishina died in
1951  and  there  is  no known  account  by  him  of  his wartime
activities.  But there are  other firsthand accounts, notably the
diary of Masa Takeuchi, a  worker at Nishina's laboratory who was
assigned  to  the  thermal diffusion  project,  and  a  memoir of
Bunsabe Arakatsu, a physicist from Kyoto.
   These materials  have been collected  independently by Herbert
F. York, Jr., director of  the Program in Science, Technology and
Public Affairs at the University  of California at San Diego, and
Charles  Weiner,   professor  of   history  of   science  at  the
Massachusetts Institute  of Technology  (M.I.T.).  Weiner  is now
completing a full-scale historical study of the subject.
   It  is  no surprise  that  physicists in  Japan  were tempted,
around  1940,  to  study the  military  applications  of fission.
Throughout  the 1930's,  Japan had  kept  pace with  the exciting
developments in physics -- with theory in Europe and experimental
techniques in the United States.   Nishina spent several years in
Copenhagen in the laboratory of Niels Bohr.
   The Japanese  also became  schooled in  the techniques  of the
cyclotron, through a small machine  built at the Riken, Nishina's
laboratory in  Tokyo, and  by sending  a much  younger physicist,
Ryokichi  Sagane,  to  Berkely   to  work  under  E.O.  Lawrence.
Lawrence arranged for the contribution  of a 200-ton magnet for a
second cyclotron  at the Riken.   The cyclotron  was not finished
until 8 years later, shortly before the war's end.
   While Japanese  physics at  the outset  of the  war was strong
enough to  carry researchers  naturally into  the problem  of the
fission weapon, it was  "too brittle," to bring  the project to a
successful  conclusion.  Nishina,  Sagane,  and some  others were
clearly world class  physicists; but Japanese  physics included a
"comparatively large number of nonadvanced fields."

                   Scientists Suggest Project

   The scientists  themselves initiated  atomic bomb  research in
September  1940.   Army  sponsorship  was  arranged,  and "fairly
large-scale research" began at the Riken "from December, 1940."
   The  years 1940  and 1941  were a  period of  intense military
interest in the possibilities of  atomic weapons.  In 1941, Prime
Minister and War  Minister Hideki Tojo's  order for investigation
of the possibilities for  a fission weapon were  passed on to the
   But in the first  of what was to  be a series of uncoordinated
orders  to  the scientists,  the  Navy also  engaged  the Riken's
services, and  launched an  inquiry into  the feasibility  of the
weapon in  late 1942.   This led  to the  "Physics Colloquium," a
galaxy of  Japan's leading  scientists who  met for  ten sessions
between  December  1942  and   March  1943,  to  investigate  the
feasibility of Japan's achieving a weapon.
   The  Colloquium's conclusion,  relayed  to the  Navy  in March
1943, was that an atomic bomb  would be impossible "even" for the
United States for the current  war.  Another account says that it
estimated Japan would need "ten  years" to develop such a weapon.
So it seems  that the scientists viewed  the project as extremely
long term at best, or, as one  of them would later write: "if not
for this war then in time for the next one."
   On the other hand, the  military viewed the bombs as something
to be pursued immediately, although it often did not back up this
commitment with resources.   The planners of  Pearl Harbor, it is
known,  assumed  that the  war  in  the Pacific  would  be short,
brutal, and  brilliant.  They  believed that  America, then being
irrevocably  drawn  into  hostilities  in  Europe,  would retreat
quickly from fighting on a second front in the Pacific.
   It is  well established that  another faction  in the Japanese
government  was  restrained  and  realistic,  and  probably  this
element took a  wait-and-see attitude, and  relegated the problem
to  the scientists.   But the  zealots were  still there.   A new
book,  Enola   Gay*,  quotes  the   physicist  Tsunesabo  Asada's
recollection that  discussions of  the subject  right after Pearl
Harbor were  characterized by  a "mood  of blind  patriotism" and
"promises of generous funding."
   Arakatsu,  writing  after the  war,  said he  did  atomic bomb
research to prevent young scientists from being sent to fight and
die.  Takeuchi, in his diary, which was also compiled after Japan
had surrendered, says that he did the research only when ordered,
and that other Riken scientists were equally unenthusiastic.
   However well  these rationales  suited the  postwar climate of
opinion,  there  is  evidence   that  the  actual  situation  was
different.  At several  junctures when the  scientists might well
have closed down the work altogether -- for they knew better than
anyone how great were  the odds against success  -- they kept the
work going.
   September  1940 had  been one  such  juncture; March  1943 was
another.  Following the physics colloquium's negative report, the
Navy branch  that had  sponsored it  lost interest  in the atomic
bomb.   But Nishina  managed to  keep  the Riken  atomic research
going.  The Army, which had  been funding the work since December
1940, became the sole sponsor of Riken atomic research.
   But this was  by no means the  beginning of coordination among
the military.   Just as the  Naval Institute  of Technology bowed
out of  support of  atomic research  in March  1943, another Navy
branch, the  Fleet Administration Center,  was sponsoring another
group of researchers at Kyoto University, under Arakatsu, to work
toward an atomic bomb.
   The Kyoto project began in 1942  and was enlarged with a grant
of 600,000 yen  in 1943.  Among  other things, the  money went to
construct a  cyclotron at  Kyoto university.   But the military's
commitment to  the work  -- however strong  in spirit  -- was not
backed up with material aid.
   Takeuchi's diary  also indicates  that atomic  research at the
Riken  was  anything but  coordinated.   Takeuchi  complains that
although he  was told to  consider the  possibility of separating
uranium  by electromagentic  means,  Miyamoto, who  had developed
such a method, had gone  to another university.  So Takeuchi gave
up  on  electromagnetic  separation   because  he  couldn't  have
Miyamoto  around  to help.   Similarly,  although  Takeuchi found
gaseous  thermal diffusion  "the  most promising"  method, Eiichi
Takeda, who had  done small-scale thermal  diffusion work using a
glass column, was not assigned  to the project.  So, Takeuchi had
to start from scratch.
   After much  delay and  red tape the  apparatus was  ready in a
separate building in  early 1945.  It took  Takeuchi 18 months to
do this work,  whereas physicists in the  United States were able
to set up comparable or larger experiments in a matter of weeks.
   In April 1945, as the  gaseous thermal diffusion apparatus and
the cyclotron  were finally  working together  in an experimental
mode, the building housing the apparatus -- but not the cyclotron
--  was  ruined in  the  American  bomber raids  over  Toko.  The
wrecking of their experiment caused  the scientists to give up on
their atomic research -- that is, until after Hiroshima.
   After  Hiroshima,   the  government   seems  to   have  become
interested yet again in having  an atomic bomb.  According to one
account,  the morning  after the  bomb  was dropped,  Nishina was
summoned and asked first whether  the bomb could have been atomic
and "whether Japan could have one in six months."
   Nishina was flown over Hiroshima  on 8 August.  The pattern of
destruction and the presence of  radiation convinced him the bomb
had been  an atomic one.   Arakatsu reached  a similar conclusion
when he was flown over the city on 10 August.
   After  Hiroshima, the  scientists at  the Riken  resumed their
atomic studies, but with a  different goal, namely to learn about
the effects  of the  weapons at  Hiroshima and  Nagasaki.  Philip
Morrison, now of M.I.T., who served on the Manhattan Project, and
arrived in  Japan on  the first  day of  the American occupation,
recalled what he found when he visited the Japanese scientists.
   Nishina  was "guarded  and  self contained  ...  impassive and
almost  antagonistic,"  toward the  arriving  Americans.   On the
other hand, many other Japanese  physicists seemed to welcome the
Americans  with  "rueful pleasure."   Morrison  recalls  that the
feelings of internationalism, of  a bond among physicists, seemed
to reestablish itself between the  Americans and Japanese -- with
the  exception of  Nishina.  And  as for  whether Japan  had been
developing an atomic weapon, he  recalls, "they didn't talk about
it and we didn't ask about it much."
   The   Riken   buildings  and   laboratories   "looked  frayed,
unrenovated,  starved of  attention."  In  places, work  had just
stopped  and  people had  gone  away.   "As we  looked  around we
concluded  this  could  not  have been  the  site  of  a Japanese
Manhattan Project."
   It is not  surprising that U.S.  scientists visiting Japan who
knew firsthand the "panoply" of installations and people that was
the American Manhattan Project, concluded that the Japanese could
not have had a comparable project.
   So it went in the  fall of 1945.  Visiting American scientists
were sympathetic to  Japanese "colleagues" and  tended to find no
evidence of  a bomb project.   The Japanese were  silent to their
American military interrogators; thus the military, by and large,
also found no evidence of such a project.
   The  Joint Chiefs  of  Staff ordered  on  30 October  that all
research facilities and  equipment "on atomic  energy and related
subjects be seized."  "No research  ... on atomic energy shall be
permitted in Japan."
   On  24 to  26 November  1945, on  orders from  General Groves'
office, which  oversaw the Manhatttan  Project, American military
teams proceeded  to hack  Japan's five  cyclotrons, including the
two at Riken, to pieces.  The remains were dumped into the sea.
   In the furor which arose in the United States, scientists' and
citizens' groups protested to the Secretary of War.  For the most
part  they  were  told  that the  destruction  order  had  been a
mistake.  But this confession of error only whetted the appetites
of many  of the  scientists, who  had now  become embroiled  in a
fight  for  future  civilian   control  of  atomic  energy.   The
destruction of  the cyclotrons was  used to  show how insensitive
the  military  would  be  to the  special  needs  of  science and

                    Admiral Nakamura "Talks"

   But was the destruction completely mindless?
   There  is a  U.S.  Army document,  dated  before the  order to
destroy the cyclotrons, in which  a Rear Admiral Nakamura reports
in detail  on atomic  bomb research  conducted during  the war at
Kyoto University.  Among  other things, it  says that the project
included the construction of a cyclotron.
   So far  there is no  evidence that the  report reached Groves'
office.  But its  existence suggests that  some Americans learned
of the wartime atomic research  and concluded that the cyclotrons
should be destroyed.
   On  31  December when  Lee  DuBridge, director  of  the M.I.T.
Radiation Laboratory,  wrote to  the acting  secretary of  war on
behalf  of   the  scientific  community,   suggesting  that  U.S.
scientists restore  "at least Dr.  Nishina's 60-inch [cyclotron]"
in  view of  the  great loss  to  physics and  the  world, Acting
Secretary of War Kenneth C. Royall replied:
     It is unsound to intimate that scientists are citizens of
   the  world alone,  are  internationalist and  not  loyal to
   their native  lands and  are never  willing participants in
   the ambitions of dictators or tyrants.  The evidence to the
   contrary  is too  overwhelming for  the American  public to
   accept this thesis, for modern  war is scientific and total
   war in toto.  Without the scientist or the technical worker
   the terrible instruments of  destruction of the present day
   would not have been possible.
     In  the  interests of  the  country and  of  the American
   scientists  themselves,  I believe  you  should  exert your
   influence to prevent any campaign  for the restoration of a
   cyclotron to the Japs at this time. ...
   The Riken was dissolved "as  a result of the defeat," although
Nishina  later  raised money  to  reestablish it  on  a different
footing.   Elsewhere in  Japan,  physicists were  restrained from
atomic  research, and  allowed only  to  work on  applications to
biology and medicine.   But without the  big equipment to support
pioneering work, Japanese physics did not reattain the prominence
it had in the 1930's.
   Could the Japanese  have had an  atomic bomb in  World War II?
All the historians, Japanese and American, echo the conclusion of
the  Physics Colloquium,  that Japan  did  not have  the uranium,
resources,  or  organization  for  a  full-scale  Manhattan-style
project.  So the danger -- as turned  out to be the case with the
Germans -- was not a real one.
   But the historical  importance of the project  lies not in the
fact  that Japan  failed  but that  she  tried, and  that Japan's
postwar attitude that she, as the one nation victimized by atomic
weapons, is  above seeking  to acquire  them for  herself, is not
historically  accurate.  The  historical record  shows --  on the
basis  of  the   eagerness  of  her   military  and  the  willing
cooperation of her scientists -- that if other factors had made a
bomb possible, the leadership -- which by the end of the war were
placing  their  own  youth  in  torpedoes  to  home  them  on the
advancing U.S. fleet -- would not  have hesitated to use the bomb
against the United States. -- Deborah Shapley

   *G. Thomas and M.M. Witts,  Enola Gay (Stein & Day, Briarcliff
Manor, N.Y., 1977).  $11.95.

--------------------[First insert (p. 153:2)]--------------------
Derek de Solla Price, Avalon  Professor of the History of Science
at  Yale,  with  Eri  Yagi  Shizume,  a  Yale  graduate  student,
investigated Japan's wartime  atomic bomb effort  and published a
letter in the Bulletin of  the Atomic Scientists in 1962, seeking
more  information  on  the project.   But  none  was forthcoming.
Price believes the effort was serious enough to "change the moral
and ethical relationship between Japan and the United States."

  "Japan's attempt to  acquire an atomic  weapon during the World
War II changes  the moral and  ethical relationship between Japan
and  the United  States that  has grown  up over  the use  of the
atomic bomb against Japan.  The story has been that the Americans
were guilty  and the Japanese  were innocent  and blameless; that
the Americans developed this terrible new weapon and proceeded to
commit an atomic rape of the then-helpless Japanese."
  "But  the fact  that the  Japanese were  trying to  develop the
bomb, too, means that  America was in an  arms race with Japan as
much as she was with Germany."

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