In Richard J. Samuels’s invaluable 1987 book, The Business of the Japanese State: Energy Markets in Comparative and Historical Perspective (Cornell University Press, Ithaca, New York), he provides a table of the overseas firms that established linkages with Japanese heavy manufacturing companies, beginning in 1955 and 1956. What could be more useful for me, teasing out how Japan entered the age of nuclear energy?

The trouble is, Samuels’s table shows no sources at all. Four of the five Japanese groups are shown as lining up with two major U.S. firms and one major U.K. firm, and these four linkages I can crosscheck. But an American firm, United Nuclear, is shown as teeing up with the Sumitomo Group as early as April 1956. Yet United Nuclear Corporation was not established until 1961. So much of that 1950s history is now lost and it takes me a long time to tease out that what Samuels means by United Nuclear is in fact a left-field nuclear reactor design company, Nuclear Development Associates (NDA), formed in 1948 by ex-Oak Ridge scientists. I deal with this company in a chapter on the reactor design wars. It pursued an especially obscure reactor design that never gained any traction at all, before being gobbled up by what became United Nuclear Corporation.
This line of investigation is like many I’ve faced: what does it all mean? Well, the Sumitomo Group did not, as I understand it, ever figure prominently in Japanese reactor history. And if NDA did in fact link with Sumitomo in 1956, such a linkage was a fleeting, shallow one of no interest to my chapter on Japan. So I take an executive decision to treat Samuels’s five-line table as having four lines only.
Of course I could be wrong. There might be a skein of history I’m now ignoring at my peril. We shall see.