History

The first suggestion of the possibility of the transmutation process for producing Plutonium was made at Princeton University in May, 1940. Research leading to this suggestion had been carried on at Columbia University since January, 1939, and studies of the process were actively continued there until April, 1942. Beginning about December, 1940, following discussions with the investigators at Columbia, the University of California undertook successfully to prepare sub-microscopic amounts of Plutonium by an alternative process, and in May, 1941, found that Plutonium had certain distinctive nuclear properties which might lead to important military applications. The desirability of investigating more carefully such military possibilities of Plutonium was urged by the University of California in July, 1941. A committee of the National Academy of Sciences took under advisement this proposal and that of the similar military use of alternative materials. The committee recommended to the Office of Scientific Research and Development in November, 1941, a vigorous investigation of the military possibilities of one of these alternative materials. In December, 1941, the Chairman of the committee proposed that the military possibilities of Plutonium as produced by the present transmutation method should likewise be intensively studied. This proposal was supported by calculations of the amounts of Plutonium required, estimates of its military effectiveness, and roughly drawn production time schedules presuming the feasibility of the process. The proposal received immediate favorable action, and beginning in December, 1941, a program of intensive Plutonium research was begun, centered at the University of Chicago, and sponsored by the Office of Scientific Research and Development.

The shortness of the time available for research since December, 1941, as well as the absolutely pioneering character of the Plutonium development, should be borne continually in mind in reading this Memorandum. The research has been conducted, and is proceeding, in the face of serious handicaps which are inherent in the nature of the transmutation process. For example, to carry out the transmutation process on the laboratory scale, even at an infinitesimal rate of production, there is required a transmutation unit of nearly the same physical size as one of the more complex large-scale units now to be constructed. Even such a laboratory unit requires about forty-five tons of uranium and uranium oxide; these amounts were not available in adequate quality until late in 1942. No such laboratory unit would produce enough Plutonium for normal laboratory-scale chemical research on Plutonium recovery, and only minute amounts of Plutonium could be made in other ways; therefore, difficult micro-chemical procedures have had to be used in developing a Plutonium recovery process. Intense radioactivity is encountered throughout both transmutation and recovery research.

In June, 1942, in preparation for large-scale operation, the Corps of Engineers assumed responsibility for direction of the Plutonium project. The contractor was first made aware of the nature and objectives of the Plutonium development in November, 1942, following a request by the office of Scientific Research and Development and the Corps of Engineers to the Contractor to render an opinion regarding the feasibility of building and operating large-scale plant for Plutonium production. In August and September, 1942, at the request of the Corps of Engineers, the Contractor had lent chemical engineers to the University of Chicago for work stated to be of great military importance but not otherwise described. In October, 1942, at the request of the Corps of Engineers, the Contractor had undertaken by Letter Contract dated October 3, 1942, to furnish engineering assistance in the design of a semi-works recovery plant but was without knowledge of the transmutation process and the objectives of the development for which the semi-works recovery plant was to be used.

In November, 1942, the Contractor assigned personnel who spent three days in a review of the Plutonium development at the University of Chicago as requested by the Government. Emphasizing its complete inexperience in the field involved in the development, the Contractor then reported to the Government that it found obvious grave difficulties but no apparent fatal obstacles to an attempt to secure early large-scale production of Plutonium, presuming favorable outcome of experiments yet to be made. The Government then requested the Contractor to undertake large-scale production of Plutonium, stating to the Contractor that the war-importance and urgency of the Plutonium development demanded that it proceed promptly to the production stage in spite of important gaps in the information normally considered necessary for design, construction and operation of large-scale plant. Having learned during its investigation of the Plutonium development that research was being conducted on two other processes for obtaining products capable of the same military use as Plutonium, the Contractor suggested that the relative merits and degrees of assurance of success of these other processes should be reviewed and compared before the Government decided finally on any program involving Plutonium production. As a result of this suggestion, the Office of Scientific Research and Development and the Corps of Engineers borrowed from the Contractor three employees to serve as members of a committee of five to investigate and compare the Plutonium and alternative developments. The committee spent six days in a review of the Plutonium process and the two alternative developments. Following report of the committee to the Government in December, 1942, the Contractor was again asked by the Government to undertake large-scale Plutonium production. The Contractor stated its reluctance to do so, emphasizing again its inexperience in the field involved. The Government insisted in its request. Thereupon the Contractor accepted the assignment by signature of a Letter Contract on December 21, 1942, and began actively to organize personnel for the work in January, 1943.

Under a supplemental Letter Contract signed January 8, 1943, the Contractor is designing and constructing a semi-works Plutonium plant to be operated by the University of Chicago. In this semi-works plant, the transmutation process to be used in the large-scale Plant under this Contract can, it is estimated, be operated at a maximum capacity which is four-tenths of one per cent (0.4%) of the designed capacity of each of the large-scale Plant units. However, the transmutation equipment in the semi-works plant will differ from the transmutation equipment in the large-scale Plant in some critical respects; this is in order that the semi-works plant can be erected more quickly and so, if it operates successfully, may produce promptly the small amounts of Plutonium which it is designed to produce and which are urgently needed for experimental purposes. Moreover, the design and construction of the large-scale Plant must proceed simultaneously with the design and construction of the semi-works plant; consequently, the design and construction of the large-scale Plant cannot take normal advantage of semi-works operating data and experience. The large-scale Plant will therefore represent not only the first attempt ever made to transmute one chemical element into another on a production scale, but also an effort to do this in a Plant designed substantially on the basis of data determined on the laboratory scale only.