Strict control over tritium production and inventory must be obtained by any electrical utility operating a magnetic confinement fusion reactor plant if they do not want to be in the business of tritium production beyond the requirements for their own plants. A computer model has been developed to analyze the tritium inventory in a multiple compartment tritium handling system. Analysis has been conducted to explore a variety of reactor system operational parameters and modes including the effects of varying the TBR to achieve a constant storage inventory, the effects of actual operational cycles including an annual down time for blanket replacement, and the effects of failures of various components within the tritium processing stream.