The Past, Present, and Future of Transient Testing in Idaho

Nicolas Woolstenhulme
Idaho National Laboratory

Transient testing is the study of nuclear materials under events that are brief in duration or changing in instantaneous conditions. Among transient conditions, postulated off-normal, accidental, and upset conditions in nuclear reactors are of great interest because they represent power-cooling mismatches that can challenge the integrity of fuel materials. Some of these scenarios can only be simulated in transient test reactors to achieve very rapid power excursions, the correct distribution of heat generation within nuclear fuel specimens, and/or to include other irradiation effects to accurately represent their behaviors. The National Reactor Testing Station, now known as the Idaho National Laboratory, was once the hub for nuclear transient testing within multiple reactor facilities. Most of these facilities have since been decommissioned and there has been a drought of US-based transient testing for over 20 years. One of these facilities, known as the Transient Reactor Test (TREAT), has been in standby for this long time. TREAT's brilliantly simple design have enabled a current project to revitalize it for future transient testing in this decade. Modern developments in materials, instrumentation, and computational sciences will combine with TREAT's capabilities to usher in a new era of nuclear transient testing for development of reactor fuels and systems with enhanced performance and safety.