Measures for Progress: A History of the National Bureau of Standards

THE BUREAU AND THE ATOMIC BOMB 383
By January 1944, to extract the first element 94 from uranium.
By January 1945, to have a bomb.57
Speed became essential. To hasten decisions, the S—i Section, grown
too large for action, was reorganized in June 1942 as the S—i Executive
Committee under James B. Conant of NDRC, with Briggs, Compton, Law-
rence, Urey, and Eger V. Murphree (of Standard Oil Development Co.) as
members. By then, five possible approaches to bomb production had
emerged holding high promise: separation of U235 by centrifuge, diffusion,
or electromagnetic methods, and production of plutonium in a uranium-
graphite or uranium-heavy water pile.58 All were scheduled to be explored
through the pilot plant stage, and all depended to a large degree on what
soon became the principal function of the Bureau, the development of ana-
lytical procedures for controlling the purity of critical materials in the reactors
and in the bomb.
Some of these materials required as many as 20 individual chemical
analyses, and spectrographic determinations of as many as 30 elements in
their raw state, before methods for refinement could established.59 By
the end of 1945 nearly 9,000 samples of materials were to come into the Bureau
laboratories and almost 30,000 separate analyses completed. Equally ex-
tensive investigations in the metallurgy and metallography of uranium were
necessary, to determine, for example, the kinds of crucible materials in which
uranium could be melted without contamination. Much work was also done
at the Bureau toward establishing radioactivity measurements and safety pro-
cedures in handling the bomb materials.60
The analytical work of the Bureau was accelerated in June 1942 with
the approval of funds for three pilot plants for U235 production and one for
plutonium. The theoretical design of the plants had been accomplished and
their construction assigned to the Army Corps of Engineers under the dis-
guise of the "DMS (Development of Substitute Materials) project." In
August 1942 the DMS project became the Manhattan District project, its
director Brig. Gen. Leslie R. Groves.
Hewlett and Anderson, pp. 54—55.
Hewlett and Anderson, p. 71.
The analytic research of the Bureau was reported in the classified Manhattan District
Technical Series. The few papers published by the Bureau after the war include a summary
account of analysis of the U spectrum, by Kiess, Humphreys, and Laun in RP1729
(1946) ;
the development of a highly sensitive method for spectrographic determina-
tion of 33 volatile impure elements in U-base materials, by Scribner and Mullin in
RP1753 (1946); and determination of the thermoelectric properties of U, by Dahi and
VanDusen in RP1813 (1947). For the work of the Bureau's mathematics group on the
atomic bomb and other wartime projects, see OSRD records, NARG 227, file MTP, Gen-
eral Correspondence.
60 NBS War Research, pp. 9—15; interview with William F. Roeser, Dec. 3, 1963.