The purpose of this report is to provide calculated liquid flow pressure drop data for the 1706-KER recirculation loops.

This report provides an overview of a gridded ionization chamber, instructions on how to operate the instrument, and then discusses the performance of the instrument so far.

The purpose of this document is to review the stud situation at Purex and make such recommendations as possible for use in any future canyon installations.

A general method is developed to allow calculation of the critical buckling of an assemblage of fissile regions coupled by neutron leakage. Consideration is given both to regions embedded in vacuum and in material media. Several cases of simple geometry are further developed to illustrate the theory.

This paper presents the results of a series of buckling measurements involving the use of enriched uranium rods (1.007% by weight U²³⁵) in light water. The effect of replacing a water reflector with one of uranyl nitrate solution of two different concentrations, 536 and 188 grams of U per liter of solution was investigated for the 0.925" rods with the 1.74 H₂O/U-volume ratio in the core. Some information was also obtained on the extrapolation length to be used in unreflected cases. The application of theory to these lattices, and others, is given in an appendix under separate title, "Buckling Calculations for One Per Cent Enriched Uranium-Water Rod Lattices."

Basic information on the design of the Knolls Atomic Power Laboratory (KAPL) -120 loop.

This twenty-fifth quarterly report of the research and development activities of the Radiological Sciences Department, Hanford Atomic Products operation, as before, includes some items charged to control but included for general interest. The previous report of this series was numbered: HW-39624, October 11, 1955. Progress is reported in the following studies: a radiobiological-ecological survey of the Columbia River; the toxic effects of continuous low-level exposure to I¹³¹ in pigs; Pu metabolism in miniature pigs and rats; the tissue distribution and retention of Ru¹⁰⁶ and Cs in rats and mice; the radiosensitivity of the intestine of rats; the pulmonary absorption of radioactive particles and the pathological effects of such particles in the lungs of mice; the uptake of I¹³¹ and other fission products from the soil and from air by plants; determinations of the relative biological effectiveness for yeast cells of Po²¹⁰ alpha particles and P³² beta particles; the development of chemical and radiological monitoring methods; the separation of fission products from waste streams; and improvements in instruments for monitoring and low-level radiation counting. The status of the research programs of the department is reviewed.

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.

A portable GM survey instrument was designed and developed which consists of a single transistor blocking-oscillator high voltage supply, a dual transistor multivibrator count-rate meter and a standard 30 mg/cm² glass-wall GM tube.