The heat generated by spent fuel elements and typical processing waste from both a 1000 MW(e) reference design pressurized water reactor (PWR) and 1160 MW(e) reference design high temperature gas-cooled reactor (HTGR) were calculated for times up to 1000 years. To compensate for differences in exposure, the heat generated was expressed in terms of watts of heat generated per megawatt day of exposure. Examination of both tabular data and graphical presentations of these normalized heat generation data indicates noticeable differences in the contribution of different isotopes for each system. As anticipated, the heat generation for each fuel was greatly influenced by the transmuted isotopes 233Pa and 238Pu for the HTGR with 137Cs and 90Sr for the PWR. Data provide quantitative detailed information on the thermal power output of typical processing waste for both reactor systems for the first millennium of cooling.