Introduction. The main objective of the Metallurgical Project was the preparation of large quantities of plutonium 239, an isotope of element 94, by the interaction of neutrons and uranium. At the beginning, only predictions of its chemical and biological properties could be made since it is a new element. It was predicted that it would be toxic to tissue by virtue of its high atomic weight, and in addition, that it would be toxic by virtue of its radioactivity. Thus, the preparation and use of the element on a large scale meant the manipulation of, and possible exposure to, toxic quantities. It was, therefore, of practical importance to obtain data which would elaborate on the predicted toxicity. The objectives of the work reported here were to establish the acute toxicity of plutonium in experimental animals and to study the distribution of the element in the body after the administration of a wide range of doses. In the interest of economy of what was, at that time, a rare substance, and of animals and facilities, these two objectives were frequently pursued in the same experiment. The information obtained from the separate experiments is therefore frequently incomplete in one or another respect. …

The HAPO Critical Incident Alarm, Model I, is an instrument designed to give an audible and visual alarm signal in the event of a critical incident to which it is exposed. There will be thirty-one (31) of these instruments installed and several spares located in the various manufacturing buildings in the Chemical Processing Department where there exists any possibility of a critical incident occurring. The instrument is intended as a post or after-the-fact warning device. It will offer no protection prior or leading up to, nor prevent, a critical incident. They are intended to be operated from the 115 V. A.C., 60 C.P.S. emergency line power. The instrument is self-contained, including the radiation detector, and will be calibrated to alarm at 500 mr/hour in a gamma field.

Nearly all nuclear reactors being designed and built today- whether for research, power, or productions of fissionable materials- use recirculating fluids for cooling. However, a number of production reactors are still operating with single-pass cooling by treated natural water. The Hanford Atomic Products Operation of the General Electric Company presently operates production reactors for the AEC at Richland, Washington. The first reactors were built during World War II, and utilized a standard water treatment which was designed to provide large quantities of settled, filtered Columbia River water for once-through cooling.

"Graft polymers were made by Co60 mutual irradiation of mixtures of styrene and methyl acrylate in contact Teflon. These graft copolymers were analyzed by infra-red absorption and their composition determined. The composition of the graft copolymer formed from styrene and methyl acrylate was different from that which is predicted by the copolymer composition equation."

"The previously found maximum in the cosmic radiation energy spectrum is discussed, and the possibility that it arises in part from a misinterpretation of the data due to oversimplifying assumptions about the composition of the beam is examined. The importance that lack of recognition of isotopic composition may have is pointed out, and it is clear that this importance is strongly dependent on the measurements made and on the cut-off rigidity."

The objectives of this study have been to examine the problems of the pebble-bed reactor concept and to conceive a design of a facility for investigating the feasibility of this type of reactor. The design must provide for adequate leaktightness of the contaminated-gas system and adequate maintenance of contaminated components, the most vital feasibility questions of the concept.