부산대학교 도서관

The Transient Reactor Test Facility (TREAT) at Idaho National Laboratory is an aircooled, graphite-moderated reactor designed to evaluate reactor fuels and structural materials under conditions that simulate various types of transient overpower and under-cooling situations in a nuclear reactor. Fuel meltdowns, metal-water reactions, thermal interaction between overheated fuel and coolant, and the transient behavior of ceramic fuel for high-temperature systems can be studied. A key instrument that monitors fuel motion as these events take place is t he fast neutron hodoscope. The hodoscope is designed to allow for pre-, during-, and post-transient imaging of fuel in a test loop in the center of the reactor’s core. The preferred technique for imaging is detection of fast neutrons produced by fission in the test fuel, travelling unmoderated through a core slot and then a multi-slot collimator to a 360detector array collinear to the collimator channels. Due to the age of the instrument, a refurbishment of the hodoscope’s fast neutron detection capability is necessary. Described here is a Multi-Purpose Test Station (MPTS) that was designed to simultaneously qualify and characterize up to eight photo-multiplier tubes using a distributed light source. The MPTS also provides a means to characterize up to eight fast neutron detector assemblies consisting of ZnS(Ag) scintillators coupled to photomultiplier tubes, using a radiologic source.