An analysis of the diffusion of fission gas bubbles and its effect on the behaviour of reactor fuels

Abstract

It is shown that small bubbles move in a way analogous to Brownian motion with an effective diffusion coefficient which is inversely proportional to their radius to the fourth power. This movement is relevant to the behaviour of reactor fuels insofar as it enables small bubbles to coalesce and an estimate is made of the rate of coalescence. The process influences the spacing of bubbles and enables a more satisfactory estimate to be made of swelling in fissile materials. © 1963.