Technical report covering classified work of the Critical Experiments Program in the Physics Division for the period December 20, 1950 to March 20, 1951. Report outlines investigations of properties of critical assemblies composed of uranium and various reflectors and moderators, preliminary measurements of the effective energy for fission in the assembly. [From Introduction and Summary]

A report about the mechanical properties of dilute uranium alloys which might be crucial to developing high strength alloys for possible use as fuel.

Report documenting two in-pile loop experiments conducted at the Battelle Research Reactor-Gas Cooled Reactor (BRR-GCR). These experiments test heat transfer calculations and the behavior of the fuel element under severe thermal-cycling conditions.

Ultrasonic inspection for subsurface flaws is widely used in American industry. This report reviews the general principles and specific techniques of ultrasonic testing. The information is based on a review of the technical literature plus the experience of the Quality Assurance Department at Sandia Corporation in applying this nondestructive testing technique to quality evaluation programs.

From introductory paragraph: "This report concerns the hydrolysis of rare-earth dicarbides, sesquicarbides, solid solutions of carbon in rare-earth metals as well as rare-earth carbon alloys of varying compositions. Many of the carbide samples used in this study were those which had been studied by Gschneider (9)(7) and had been preserved in evacuated, sealed tubes. Some additional preparations of the sesquicarbides were made especially for these studies. The hydrolytic reactions were carried out in water and hydrochloric acid solutions of varying concentrations. Assay of the gaseous products was by mass spectrometry and gas chromatography. Both instruments were carefully calibrated with pure hydrocarbons and hydrogen and mixture thereof."

"In an effort to prolong the life of certain equipment, an investigation has been made of the applicability of several high temperature ceramic coatings prepared by the National Bureau of Standards Laboratories."