From abstract: "When uranium is heat treated at low beta-phase temperatures and air cooled, the rate of loss of preferred orientation is markedly less than the rate of coarsening of the grain structure. A coarse-grained structure cannot therefore be taken as an infallible indication of satisfactory heat treatment. The final grain size of incompletely transformed metal is essentially equal to or larger than the starting grain size. Large-grained specimens can not be refined by interruption of the transformation at an intermediate stage."

From abstract: "Calculations are made of the magnitude of the radiation bursts that can occur in a mixer-settler and in a large tank containing U235 solution if the concentration gets out of control. Various rates of increase in concentration are studied and various restraints are imposed on the expansion of the systems. The neutron kinetics equations, with five groups of delayed neutrons, and the equations relating the neutron flux to the pressure and volume of the gas formed by fission fragments are combined into a single first-order nonlinear differential matrix equation which is solved numerically on the IBM 650. In a mixer-settler containing 9.7 kg of U235 the magnitude of the burst was calculated to be about 10^17 fissions, both for low rates of increase in reactivity (<[or equal to]0.01% per sec) regardless of the confinement, and for an unconfined system regardless of the rate of increase reactivity. In a tank containing 88.9 kg of U235 successive bursts of about 10^19 fissions were calculated to occur about 0.5 second apart when the rate of increase in reactivity was about 0.1% per second."