TRANSIENT DIFFUSION THROUGH A SPHERICAL SHEILA INTO ITS FINITE SPHERICAL CORE

摘要

The problem of the diffusion of gas through a spherical shell into its spherical core is solved by using the Laplace transform technigue. The transformed solution is obtained and then inverted to the corresponding solution in real space. This real space solution is slowly converging for small times. Therefore, an alternate expression is obtained that is appropriate and more rapidly convergent for small times. As an example, the first solution is used to calculate the theoretical gas content of the core of High-Temperature Gas-Cooled Beactor (HTGB) biso-coated fuel particles from fuel-particle batch OB2261/HT after 850°C anneals in helium.