Material
Controls in the Early U.S. Weapons Program2
During the
atomic bomb development in World War II, careful control was
maintained over nuclear material not only to protect military
secrets, but also because every possible gram of material produced
was needed to fabricate the first weapons. Plant managers and their
military supervisors were fully informed of the status of the
material and its use. Material balances were important primarily in
order to improve and control the processes involved, and to ensure
that all available material was converted to its intended use.
Though plant
inventory information was accumulated, no formal materials control
over the entire operation had been instituted by the end of 1946
when the Manhattan Engineering District operations were transferred
to the newly established AEC. In 1947 a small group was formed
within the AEC into the Source and Fissionable Materials
Accountability Branch of the Production Division. From its
inception, the functions of this group were accountancy and control
against loss. The number of AEC operations and the quantities of
material involved increased greatly in the 1950s, but the general
direction of the Materials Accountability Branch and its successors
did not change until the mid 1960s.
During the
1950s and early 1960s, material balances—the backbone of
modern material accountancy systems—generally were not closed
by a complete series of measurements. Measurements were dependent
on the willingness of production managers to make them, and many
production managers did not see the need for measurements on scrap
materials. In some very important cases, the measurement procedures
simply did not exist.
The nuclear
material control function was upgraded in the early 1950s to
divisional status as the Division of Nuclear Materials Management
at AEC headquarters. Even though the Division's control system was
incomplete, the overall security against loss was high. The AEC had
multiple avenues for protection against loss. To achieve the
necessary control over material involved in its operations, the AEC
depended on responsible management furnished by its operating
contractors, employees whose loyalty and reliability were subject
to security clearance, and on physical protection measures at the
facilities involved; and finally, material accountancy. With these
measures in effect, transfers of materials between plants or
operations were considered transfers between friends. Separate
measurements by shipper and receiver were infrequent and, if the
measurements taken indicated the existence of a discrepancy, it was
frequently negotiated away.