Dragon reactor

UK experimental HTR, operated from 1965 to 1976 / From Wikipedia, the free encyclopedia

Dragon was an experimental high temperature gas-cooled reactor at Winfrith in Dorset, England, operated by the United Kingdom Atomic Energy Authority. Its purpose was to test fuel and materials for the European High Temperature Reactor programme, and it was built and managed as an Organisation for Economic Co-operation and Development/Nuclear Energy Agency international project. It operated from 1965 to 1976.[1] The site extended to 129.4 hectares (320 acres) of heathland in rural south Dorset, and nine different experimental reactors were located there.[2]

Many designs of the 1960s and 70s were based on this general tristructural-isotropic (TRISO) fuel concept, including "prismatic" designs with fixed fuel layouts like Dragon, and the pebble-bed reactor designs being developed in Germany. As of 2019, these concepts have been used in several further research reactors, including Peach Bottom, AVR, HTTR, and HTR-10 as well as for commercial reactors Fort St. Vrain and THTR-300. The HTR-PM in China is under construction, with one unit at Shidao Bay connected to the grid as of December 2021.[3] Of the nine experimental reactors at Winfrith, only the Dragon Reactor and the Steam Generating Heavy Water Reactor remain, and they are in the process of being decommissioned. During decommissioning, the reactor vessels will be placed in reactor safestores, other structures will be dismantled and stored, any remaining waste will be sent to allocated storage sites, and the soil will be removed as necessary to a suitable Low Level Waste Repository. Finally, the site will be declassified as a nuclear licensed site, landscaped and returned to normal use.[2] The contract for decommissioning the site has been awarded to Costain Nuclear, and the final decommissioning phase has been deferred for twenty years.[4]