The Effects of a Decaying Heat Source in a Rectangular-Shaped Rock Repository

Abstract

Schemes for the disposal of medium to high level atomic waste involve placing the spent material in repositories deep within stable rock formations. The waste will continue to generate heat after storage underground, and it is of interest to be able to predict the effects of this heating on the surrounding rock, as this may lead to cracking of the rock and the potential contamination of ground water. A solution method is presented for problems involving decaying heat sources of rectangular shape which lie within horizontally layered materials. The method requires very little computer storage (unlike finite element and finite difference techniques) and may easily be implemented on microcomputers. Solution of the time-dependent problem is achieved by applying Laplace transforms to the field variables, solving the resulting equations, and then using numerical inversion to obtain the solution in real time.