When beryllium is irradiated by fast neutrons, helium is produced by the (n,2n) and (n,α) transmutation reactions. Electron microscopy techniques have been used to study the nucleation and distribution of helium bubbles in several different grades of beryllium, after irradiation at temperatures in the range 75 — 700ºC. The effect of post-irradiation annealing is also reported. It is shown that for similar neutron doses and irradiation temperatures, there were wide variations in helium bubble size and distribution in specimens of beryllium fabricated by different methods. The most satisfactory material was that fabricated from Pechiney powder by direct hot extrusion followed by annealing for one hour at 800ºC and air cooling, it is suggested that the helium bubbles nucleate on second phase precipitates and that the distribution of this phase is strongly affected by fabrication and heat treatment.

Measurements were made of the capacity of pre-treated Victorian brown coal for removing trace quantities of Sr2+ and Cs+ at pH 8.0 and 9.5 in the presence of various concentrations of Ca2+. At 20 p.p.m. Ca2+ breakthrough was immediate.

Some preliminary measurements have been made of the rate of dissolution of beryllium when refluxed with ammonium fluoride solution. The rate of dissolution exhibits pseudo first order dependence on the "free" fluoride concentration defined as the concentration of total fluoride less that assumed to be present as BeF4. The solubility of uranium metal in ammonium fluoride - beryllium fluoride solutions increases with free fluoride concentration, where the uranium is present in solutions as U(1V). Thorium metal is attacked only slightly under similar conditions. Beryllium may be selectively leached from UBe13 by ammonium fluoride solutions if the fine A-/Be mole ratio is greater than 4:1. The solubility of uranium under these conditions suggests that this is not a satisfactory solvent for mixtures of these alloys with Be when the U/Be ratio is small, but that it could be used successfully as a decladding agent for an oxide fuel clad in beryllium meta.