Organic compounds have been considered for use as reactor coolants for two primary reasons. First, the high boiling points of the compounds would permit the reactor to operate at high temperature without the need for the high pressure required when water is used as a coolant. Secondly, the compounds are less corrosive than water and would permit the use of carbon steel rather than stainless steel components in the reactor. Unfortunately, the organic compounds proposed for use as reactor coolants have a greater tendency to leak than water and are thus more difficult to seal. A development program was established to evaluate the types of closures required to produce a leak-tight system. This report presents the results of the evaluation. Two proposed coolant compounds, monoisopropylbiphenyl (MIPB) and the eutectic mixture of 55 per cent ortho terphenyl, 25 per cent biphenyl, and 20 per cent meta terphenyl were used.

At the request of 234-5 Development, studies of a system for controlling plutonium powder transfer were undertaken by Process Equipment Development. This report presents details of equipment designed to fulfill requirements and proposes equipment for installation on additional Hot Button Line prototypes.

Primary control of the PRTR is achieved by regulating the level of the heavy water moderator which is held in the reactor vessel by a helium gas balance system. Emergency shutdown is effected by a gas-balanced moderator dump system which drain the moderator from the calandria at a rapid rate. This report presents a quantitative appraisal of the reactivity effects due to moderator level changes in controlling or scramming the reactor. In conjunction with the reactivity calculations, solutions were obtained which yield an evaluation of vertical flux or power distributions for any positioning of the moderator level. Coupled with the radial distributions for a given fuel loading, this information is useful in obtaining the value of the maximum specific power associated with a given power of operation and moderator height. The calculations were made using VALPROD, a one dimensional, multigroup diffusion theory reactor code programmed for the IBM-650 computer.