Heeding the Lessons of History

This article focuses on learning from the successes and failures of the first-generation reactor development. Reactor designs have evolved over time to meet increasingly rigorous demands for safety and to take advantage of technological developments to improve their economics, but these changes have been piecemeal. Although light-water reactors are the most common reactor technology in use today, heavy-water reactors were actually developed earlier. The earliest demonstration of a heavy-water moderated and cooled reactor took place in May 1944 at Argonne. The reasons for the domination of water-cooled reactors, and particularly of light-water reactors, are complex. The article suggests that it is interesting to speculate on how the new initiative to develop more advanced designs may play out. There are already strong pressures to focus on the integral light-water design; based on well-understood light-water technology, the argument goes, such designs will be much easier to develop and license. In the longer term, however, some of the non-light water reactors could ultimately achieve greater levels of passive safety, efficient fuel utilization, economic performance, and proliferation resistance.