The OCR concept was a major area of research in the 1950s and 60s, including the Organic Moderated Reactor Experiment at the Idaho National Engineering Laboratory, the Piqua Nuclear Generating Station in Ohio, and the Canadian WR-1 at Whiteshell Laboratories. The US experiments explored the use of organics for both cooling and moderation, while the Canadian design used a heavy water moderator, as did the unbuilt EURATOM ORGEL and Danish DOR designs. Ultimately none of these would be used for commercial generators, and only the small experimental reactors at Piqua in the US and Arbus at the Research Institute of Atomic Reactors in the USSR ever generated power, and then only experimentally.
