The heat flux and destruction and removal efficiency (DRE) measurements have been made on 100, 150 and 200 mm diameter plasma reactors to optimize the performance. The DRE was measured for pressure and gas atomization techniques of waste injection using both argon and CO2 gases. As a result, the design of the reactor was optimized and the waste throughput vas increased by similar to17% with improved destruction performance. The 150 mm diameter reactor vas found to perform better using gas atomization of feed injection using carbon dioxide at the given power and waste feed rate.