Carl E. Crouthamel

Oxygen potential of irradiated urania--plutonia fuel pins

Abstract The oxygen-potential gradient in irradiated urania-plutonia fuel pins has been estimated from the distribution of molybdenum between the noble-metal-alloy inclusions and the oxide matrix as measured using an electron microprobe. The values of the oxygen potential were found to be more negative than would be computed for the fuel on the basis of the initial O/M ratio, thus indicating that the overall O/M of the fuel was decreased by irradiation. The O/M gradient has been computed and an oxygen material balance was determined between fuel oxide, fission products, and cladding. The nearly identical oxygen pressure profiles found for fuel pins irradiated for a range of values of the burnup indicates that the oxygen-potential gradient is establsihed early in the irradiation period, probably at the time the structure has been established and then remains nearly constant. The oxygen lost during the restructuring period is determined by the initial O/M of the fuel, the smear density and the temperature gradient. The oxygen lost during the burnup period is proportional to the burnup.

PAPER CHROMATOGRAPHIC ANALYSIS OF IRRADIATED URANIUM IN A HYDROFLUORIC ACID MEDIUM

Abstract Chromatographic papers have been found compatible with aqueous hydrofluoric acid developing solutions to approximately 60 per cent by weight of the acid. Hydrofluoric acid is also an important solution and complexing medium in the processing and analysis of certain irradiated targets and fissile materials. The aqueous-hydrofluoric acid and methyl ethyl ketone-hydrofluoric acid media have proved to be a very convenient and versatile system in the isolation of carrier free isotopes and in the analysis of irradiated materials. The complete or partial separations of twelve fission and neutron capture isotopes of irradiated uranium are described. The identification of the isotopes has been made in most cases with a 256 channel scintillation spectrometer.

Decay characteristics of potassium-42 and tellurium-132☆

Abstract The γ-spectra of potassium-42 and tellurium-132 have been examined with a sodium iodide crystal spectrometer. A recently reported 53 keV γ-transition has been observed in the decay of tellurium-132. Coincident summing in a single sodium iodide crystal at high geometry is used to reveal the main features of the relatively simple γ-decay schemes.

Studies of Lithium Hydride Systems. II. Solid—Liquid Equilibrium in the Sodium Chloride—Lithium Hydride System

Thermal analysis has been used to determine the temperature—composition solid—liquid equilibrium diagram for the lithium hydride—sodium chloride reciprocal system. A eutectic composition of 55.2 mole % lithium hydride was observed, melting at 565.7°C. No evidence for the formation of solid solutions was observed. The values of chemical potential of each component have been calculated along the equilibrium curves where the solutions are saturated with respect to the pure solids. The limiting slopes of the saturation curves are consistent with the interpretation that sodium chloride exists primarily as an un‐ionized monomer when dissolved in lithium hydride and that lithium hydride also exists primarily as an un‐ionized monomer when dissolved in sodium chloride.

Paper chromatographic analysis of selenium, tellurium, polonium, and bismuth

Abstract The chromatographic analysis of 210Po, 210Bi, 127,129Te, and 75Se in hydrochloric acid and hydrofluoric acid developing media is described. This method of isolation of 210Po from bismuth targets gives in a single operation clean samples at 100 % yield. The solutions of 210Po were obtained in very small volume and were suitable for high resolution α-pulse analysis.

The quantitative determination of fission and nuclear reaction products

Abstract Definitions are given to the terms “per cent atom burn-up” and “per cent atoms consumed” as applied to nuclear fuel analysis at the Argonne National Laboratory. The radiochemical and analytical methods which have been adapted and developed especially for this type of analysis are discussed. The analysis of nuclear reaction products by paper chromatographic methods and scintillation spectrometry is emphasised and demonstrated.

Studies of Lithium Hydride Systems. III. Solid—Liquid Equilibrium in the Lithium Bromide—Lithium Hydride and Lithium Iodide—Lithium Hydride Systems

Thermal analysis has been used to determine the temperature—composition solid—liquid equilibrium diagrams for the two binary systems, LiBr–LiH and LiI–LiH. Both are simple eutectic systems with no experimental evidence for the formation of solid solutions. Eutectic compositions of 29.7 mole % lithium hydride, mp 453.3°C, and 23.5 mole % lithium hydride, mp 390.8°C, were observed for the bromide and iodide systems, respectively. The values of the chemical potential of each component have been calculated along the equilibrium curves where the solutions are saturated with respect to the pure solids.The limiting slopes of the saturation curves are consistent with the interpretation that lithium bromide and lithium iodide both exist primarily as un‐ionized dimers when dissolved in lithium hydride and that lithium hydride exists primarily as an un‐ionized monomer when dissolved in either lithium halide.

The absolute yield of Cs137 in fast-neutron fission of U235 and Pu239

Abstract The absolute fission yield of Cs 137 has been determined for fast-neutron fission of U 235 and Pu 239 . The number of fissions was determined by absolute counting of the fission fragments. The Cs 137 was determined by absolute β counting with an end-window proportional counter. The yields were found to be 6·87 per cent and 7·45 per cent for U 235 and Pu 239 , respectively. These values are based on a Cs 137 half-life of 32·6 years.

Thermogravimetric decomposition of thorium 8-hydroxyquinolate

Abstract The thermogravimetric behaviour of crystalline thorium 8-hydroxyquinolate has been correlated with empirical and molecular formulae. The first of two sharp breaks is shown to be due to both water and oxine, and the second to oxine alone.