Irradiation of process tubes containing appropriate parent materials has been proposed by Manufacturing as a method for obtaining new products from the Hanford Reactors. The process tubes would be removed at appropriate intervals and shipped to separations plants for recovery of the products. The tube residence in the reactor could be determined by the optimum irradiation period for isotope production rather than by the period required to corrode tubes of current design to the minimum permissible wall thickness at replacement. This paper, presents an analysis to determine the benefits from red reducing the initial wall thickness of the process tubes below the current 65 mils when the desired residence for isotope production is shorter than the residence based on maximum permissible internal corrosion for tubes of current design.