Development of Nuclear Instruments to Measure Power Distribution of HTGR (1)Development of Ex-core Detector

has been conducted a joint-research to develop nuclear instrument for High Temperature Gas-cooled Reactor (HTGR) core power distribution In the project, we developed the ex-core detector system to avoid heigh temperature environment of the HTGR core.The system achieves the measurement by taking advantage of the HTGR core feature of long flight length neutron due to the graphite moderated core with Computed Tomography (CT) technologies.The theory is demonstrated by calculation in HTTR (High Temperature Engineering Test Reactor) and criticality experiment in KUCA (Kyoto University Criticality Assembly).These technologies are expected to be applied to other reactors.