LXXII. Creep of alpha uranium during irradiation with neutrons

During neutron irradiation at 100°c alpha uranium creeps slowly (e.g. 10−−7 per hour) under external stresses of order of one-hundredth of the normal yield stress of the metal at that temperature. This effect is predicted as a consequence of the phenomenon of “radiation-growth” which occurs in uranium, and is then confirmed by creep experiments on helical springs of natural uranium in a flux of 1·3×1012 thermal neutrons per cm2 per sec. In addition to this steady-state creep, transient effects occur at the start of irradiation and when the neutron flux is removed.