Abstract. A review of all work on uranium hydride published in the CC, CT, CN and CE reports to January 1, 1944, is presented. Some additional information not yet published has been included, so this report includes all data known from the above sources and at Ames to the above date. This report supersedes all previous report on uranium hydride coming out of the Ames laboratory.

Introduction. the colorimetric determination of iron based on the formation of the colored ferrous-1,10-phenanthroline complex has been used successfully by a number of investigators. In this technical report, its adaptation to the routine determination of iron in cerium, thorium, and beryllium metals and their compounds is described.

Technical report describing the purification and separation by distillation of UO2F2 from D2O. In the experiment which is discussed 2,129.6 lbs of UO2F2 were dissolved in 6,605 lbs of D2O. The average isotopic purity of the D2O decreased during the distillation from 99.77% to 99.73%. The dissolved impurities were less than those present originally in the heavy water.

Technical report. The effect of temperature during pile exposure on the fast-neutron-induced change in properties of graphite was studied. Temperatures up to 125 degrees C have no effect upon the rate of increase of elastic modulus; pieces exposed at 300 degrees C on the other hand show no change at all in elastic modulus. The increase in electrical resistance s an inverse function of the temperature of exposure at all temperatures in the range 60 to 300 degrees C.

Abstract. Samples of pile graphite, irradiated in a test-hole at Hanford for 15 months, have been assayed for radioactive C14, yielding 0.38 ± 0.04 microcuries per gram. At this level of activity, the pile graphite contains very valuable amounts of C14. The relation between the above assay and the probable average assay of pile graphite is discussed, and it is concluded that the latter is almost certainly above 0.3 uc/ gram. Controlled oxidation of this graphite, either with oxygen at ~ 750°C, or with chromic acid "cleaning solution" at room temperature, yields early fractions which are highly enriched in C14. Concentrations of 5-fold with oxygen, and 50-fold with CRO{sub3}, have been observed. The relation between the observed enrichment and the Wigner effect is discussed, and a mechanism accounting for the observations put forward. According to this, about 25% of the stable carbon atoms in the lattice have been displaced by Wigner effect, a large fraction of which have healed the migrating to crystal edges. All the C14 atoms have been displaced, and the same fraction of these migrate to the edges. The enrichment then results from surface oxidation, in the oxygen case. Predictions are made on the basis of this …