Introduction: "In the evaluation of pile designs it is necessary to know how the production varies with the number of tubes. It has been possible to solve the problem in terms of some general parameters whose values may be quickly computed for any specific design when the pertinent information is available."

A manipulator designed to support an irradiated slug at the bottom of the viewing basin, so that an operator could view it through a binocular telescope and be able to see all surfaces, was designed. Hydraulic power, using water, operates the manipulator and gears.

The first of two general methods are discussed based on the removal of the thin layer of aluminum to which graphite adheres. Two electro-polishing techniques, an electrolytic etch, an anodization-deanodication cycle and two chemical etches are described.

The hydrogen contents of several types of fabricated uranium have been determined by a vacuum method and expressed in terms of ccH2/ccU. The data indicate that alpha-rolled metal contains about 0.25 ccH2(STP)/ccU whereas beta heat-treated uranium yielded values between 0.30 and 0.37 cc per cc. Restricted efforts were made to determine where in the heat treatment the 5 to 10 cc of hydrogen per slug were taken up. It appears that no one operation is wholly responsible for this additional gas, although reactions between beta heat treated surfaces containing microscopic defects, and nitric acid may possibly play a large role. In general it may be said that slug produced by powder metallurgical techniques contain less hydrogen than pieces produced by rolling and heat treatment.

Observations on sheep representing flocks in Utah adjacent to the Nevada Proving Ground were compared with findings made on experimental sheep exposed to various amounts of radioiodine. The Utah sheep showed no evidence of the radiation damage observed in experimentally treated sheep. Estimations of amounts of radioiodine on vegetation required to cause serious thyroid damage following a contamination event are included.

The very strong flux gradient in the MTR reflector might be thought to be some cause of worry. However, this gradient will be minimized by the presence of the large block of aluminum, which, because of its small effect on neutrons, will tend to flatten the neutron flux in its vicinity. Advantage should be taken of the shape of the test facility by placing the water hole corner closest to the MTR core. This placement should take best advantage of the flattening potentialities of the slowing-down flux from the test slugs, by placing the nearest (beryllium) moderator on the low flux side of the assembly.