Report discussing experiments on the interaction of neutron-absorber materials and metal matrix materials used in the fabrication of control rods, such as "boron, cadmium, and some of the rare-earth elements such as gadolinium and europium...In order to evaluate the reactions that might occur during fabrication and use, experiments were carried out in which combinations of the various control materials were heated in intimate contact with the several matrices at elevated temperatures."

From introduction: "The study's objectives were to determine the approximate rate of general corrosion so as to reveal; any abnormal corrosion occurring during processing operations; to determine the suitability of a large variety of alloys and plastics as materials of construction; and to ascertain process conditions which would minimize corrosion."

A preliminary report has shown the potential importance of organic reactor coolants to Hanford technology. The salient points are complete avoidance of corrosion problems and accomplishment of DPR performance with low pressure technique. The recommendation of the report that loop tests be made at Hanford is to be acted upon by Recirculation Technology Unit as soon as organic coolant material is received. To insure starting this experimental work fully abreast of the information available, a trip to sites working with organic coolants was made. Specifically, data were sought on practical details of design for handling organic coolants, heat transfer and fouling characteristics, corrosion of materials, and hazards of handling organics.

Among the safety considerations for the Purex plant is the question of flammability limits for the diluent-air system. The present note attempts to delineate the temperature regions of concern by utilizing hydrocarbon flammability data available together with information on the vapor pressures of the systems.

An investigation of corrosion in the 327 Building's water storage basin was made to determine whether the static storage of aluminum jacketed fuel elements could cause corrosion effects that would interfere with studies of in-pile corrosion.

Prevailing dimensional tolerance for sintered UO₂ reactor fuel components to be enclosed in metal jackets are expensively small. For instance, the PWR fuel pellet, as of November, 1955, consisted of a centerless ground UO₂ cylinder 0.3560" (+0.0005", -0.000") in diameter and 0.3527" (±0.0008") long. This pellet was designed to fit in a Zircaloy tube 0.3585" (+0.0005", -0.0000") inside diameter. The use of UO₂ shapes as pressed, or extruded, and sintered with diameter variations controlled to a tolerance of ±0.003" to ±0.005" would represent a fabrication cost saving worth considering. It is reasonable to assume that the annulus between a sintered UO₂ shape and its container will vary as a function of time of irradiation. Shrinkage from the can walls occurs with relatively low density (i.e., 85% of theoretical) sintered irradiation (cf. MTR Test GEH-4-3C). Contrary to this effect, the thermal expansion coefficient of UO₂ is about twice that of Zircaloy. Of possibly greater significance is the inevitable fractuce of dense UO₂ due to thermal stress. Such cracking effectively relocates the annular heat transfer gap to the interior of the oxide where the higher temperatures enhance the heat transfer coefficient. Thus, possibly the worst condition, with respect to heat transfer, is …