Needs for Safety Analysis on High Temperature Gas Reactor Plant

High temperature gas cooled reactor (HTGR), originally developed in the early 1950s in the United Kingdom and France, utilizes a single phase gas coolant and graphite as a moderator. There are many designs of HTGR, such as pebble-bed type and modular type. They may range from small modular designs to large central station plants. Although safety level of HTGR is greatly enhanced by its advanced design features which were briefly analyzed in this paper, there are still many research needs and safety issues associated with HTGRs which require further research. The research needs for experimental verification of HTGR safety was therefore investigated and classified. The safety issues and research needs were classified according to technical areas they pertain to. It should be noted that, only technical areas including thermal-hydraulics, reactor fuel, reactor physics, severe accidents were covered due to limited time in this paper. The capabilities of test facilities available in the world were also investigated and classified. Based on the test facilities ranging in size and complexity from small-scaled component tests to scaled entire system tests, analysis on matching ability between safety analysis issues and test facilities was conducted. Finally, the suggestions constructing experimental research system for safety analysis were concluded.