Steam-generating heavy water reactor
Steam Generating Heavy Water Reactor (SGHWR) is a pressure tube type, heavy water moderated, ordinary (light) water cooled nuclear reactor. The steam generating heavy water reactor is in principle the same as a BWR but relies on a special heavy water material as the moderator whilst using conventional water as the primary coolant. They are similar in design to the CANDU, which uses pressure tubes and separates the coolant and moderator - the Gentilly-1 CANDU-BWR prototype was in fact a reactor of this type. The modern CANDU ACR-1000 reactor design uses a similar concept.
There are only a limited number of examples of this design, the major one being at Winfrith in Dorset, UK, a 100 MW reactor which ceased operation in 1990 after 23 years of successful operation having reached the end of its design life.  It was owned by the United Kingdom Atomic Energy Authority. Decommissioning is now being carried out by Research Sites Restoration Limited on behalf of the Nuclear Decommissioning Authority. Another example was the Italian project CIRENE, hosted at Latina Nuclear Power Plant.