2017 | AFC ACCOMPLISHMENTS 119 experiments, which oftentimes includes considering consequences of fuel failure well-beyond limits imposed on commercially deployed technologies.While establishing needed experimental capability, this research will also provide opportu- nity to begin further investigation of related FCI behaviors for: 1) potentially reducing uncertainties and impacting limits used to guide fuel usage including for high burnup fuels, which have a high propensity for fragmentation and dispersal into coolant, conducive of energetic FCI behaviors; and 2) advanced fuel concepts that have little to no in-pile experimental FCI exploration. Accomplishments: The primary goal of this work is to develop capabilities to analyze FCI events with an initial focus on reac- tivity initiated accident (RIA) related phenomenology. Initial work at Idaho National Laboratory (INL) has focused on compiling information from historical in-pile experiments. Several historical facilities located on the present-day INL site have contrib- uted to the experimental under- standing of FCI physics and resulting nuclear fuel system behavior.Testing in these facilities provided much of the foundational knowledge of fuel system response, data for model validation (some still unique in the world), and set a precedent for the experimental approaches used to study FCI phenomena. In particular, reactor tests performed at BORAX and Special Excursion Reactor Test (SPERT) reactor facilities provided much early insight into large-scale system behaviors. In the 1960’s, capsule type experiments were started in the TREAT and SPERT Capsule Driver Core (CDC) experiments with a focus on in-water behavior up to very high energy depositions. By the mid-1970’s, experiments began in the Power Burst Facility (PBF) utilizing a prototypic water loop capable of operation to Pressurized Water Reactor (PWR) conditions. In theTREAT reactor, one experiment device provided access for high speed videography of RIA experiments in water. Many of these resulted in FCI events with an example given in the video frames shown in Figure 1. Figure 2 shows the compiled peak pressure rise measured in experi- ment coolant as a function of energy deposition in the fuel.The results demonstrate increased severity of the resulting pressure spikes with water- logged fuel rods and some indication of increased pressure pulse severity for powder form fuels and pre-irradiated fuels. Overall, the data obtained for measured peak pressure also illustrates a stochastic nature for FCI events. With a few exceptions, it is notable that the majority of the experiments performed to simulate high energy