Concurrently with the production of canned uranium slugs for pile operation there arises the problem of nondestructive testing so that no slug which may fail structurally during operation be placed in the pile. The ultimate goal of any such testing program is to devise nondestructive testing methods which will eliminate defective slugs. A secondary goal of the testing program is to learn as much as possible about the construction of the canned slug so that the mechanisms of failure can be understood. Radiography, an increasingly useful nondestructive test method, offered one possible way of investigating this area.

The purpose of this work was to study reagents which might be effective in dissolving uranium oxide produced during slug failures in water-cooled reactor systems. An aspect of this problem which has subsequently become of primary importance is the solubility or transportability of the oxide in pure water.

A plutonium-aluminum alloy containing 4 atom per cent aluminum showed no attack after exposure to purified NaK for one month at 400 C in the absence of any oxide. The same specimen and other plutonium alloys, including pure plutonium, showed marked deterioration in shorter exposure in the presence of oxide films from a welded stainless steel container. Pure uranium was resistant even in the presence of such oxides.

A method for monitoring radiation damage irradiations using the change of the electrical conductivity of graphite is described. Results of monitoring operations in a number of locations are given. An attempt is made to explain the damage rate found in the converter at CP-3. An estimate of the flux spectrum in VT-4 and the converter of CP-3 is made and the damage rate is computed according to theories of Seitz and James. It is found that the experimental results are more in accord with the predictions of Seitz. A number of corrections to James' report, ORNL-307, are noted in an appendix. It is shown that some information about the fast flux spectrum can be inferred from the radiation damage rate.

From Review of Theory: " In practice, a very close approximation to the molecular orbitals can be obtained in this way. Recent calculations of this type, utilizing analysis and computer programs developed by the author, have resulted in the determination of the molecular orbitals for a large number of diatomic molecules in the form of Eq. (2). These functions, which are thought to be very close to the Hartree-Fock (i.e., the molecular orbitals demanded by theory) result, were used in the pictorial calculations presented in this report."

Report issued by the Argonne National Laboratory discussing the Liquid Metal Fast Breeder Reactor Nuclear Safety Program. The work completed by the program between 1969 and 1970 is presented. This report includes tables, illustrations, and photographs.

Report issued by the Argonne national Laboratory discussing a technical and economic evaluation of a direct-cycle light-water boiling reactor designed for natural circulation and internal steam-water separation. The reference 100-Mw(e) reactor power plant design evolved from the study should have the best chance (compared to similar plants) of approaching the 8 to 9 mill/kwh total power-cost level. This report includes tables, and illustrations.

Report issued by the Argonne National Laboratory discussing irradiation tests of an aluminum alloy-clad, aluminum-uranium alloy fuel plate. As stated in the introduction, "calculations were made to determine the lowest possible pressure which would allow the maximum possible local boiling on the plate and still assure a margin of safety against burnout" (p. 9). This report includes tables, illustrations, and photographs.

Report issued by the Argonne National Laboratory discussing the performance of magnetohydrodynamic generators. As stated in the abstract, "an experimental study was made of the performance characteristics of a liquid metal MHD generator utilizing single-phase sodium-potassium and two-phase sodium-potassium-nitrogen fluids. The purpose of this study was to compare the generator performance with theory for single-phase flow and to determine the effects of the introduction of the gaseous phase on the generator output and efficiency" (p. 9). This report includes tables, illustrations, and photographs.

Report issued by the Argonne National Laboratory discussing progress made on reactor development. Progress made on the core, pressure vessel and shield, and the power plant are presented. This report includes tables, and illustrations.

Physical calculations have been performed for various combinations of the four types of fuel assemblies to be used in the EBWR core. Two thicknesses of plates (0.205 in. and 0.274 in., including two 0.020-in. cladding layers) are to be made of both natural uranium and uranium containing 1.44% U235. Any given fuel assembly contains six identical plates. A total of 148 assemblies, 74 natural and 74 enriched, are to be fabricated. Various configurations of these fuel assemblies can be used to (1) change the critical size of the core, (2) change the power distribution in the core or (3) change the amount of reactivity corresponding to a given steam volume in the core. Physics calculations show that any uncertainties in the required critical mass are adequately covered by the number and variety of fuel assemblies, and that the changes in core characteristics possible with the different fuel assemblies should provide valuable information about the factors affecting maximum power density and stability in a boiling reactor.

A fused fluoride process for dissolution of zirconium-uranium fuel alloys is being developed. The alloy is dissolved in an equimolar sodium fluoride-zirconium fluoride melt at 600°C by sparging the system with hydrogen fluoride. The uranium is volatilized from the melt as the hexafluoride by a sparging operation with fluorine or bromine pentafluoride vapor. This product is then decontaminated and purified by fractional distillation.