2018 | AFC ACCOMPLISHMENTS 17 possible for a researcher to isolate, for example, fission product mobility in an experiment without also assuming important details like temperature and microstructural evolution.The multifaceted drivers of cost, time, and complexity have prompted nuclear engineers and material scientists to explore alternatives to integral testing. The Advanced Fuels Campaign (AFC) has identified one potential solution using the High Flux Isotope Reactor (HFIR).The MiniFuel test is designed to overcome the traditional chal- lenges of integral testing and offer researchers an efficient but powerful tool that supports a science-based approach to fuel qualification. Project Description: The MiniFuel design concept places fuel specimens inside individually sealed sub-capsules encapsulated by steel targets in the reflector of the reactor.Temperature is controlled by sizing an insulating gas gap between the sub-capsules and the target housing. Reducing the size of the fuel allows for very high fission rates (on a per unit mass basis) without prohibitively large temperature gradients. Furthermore, the small fuel mass results in the total heat generated in each sub-capsule being dominated by gamma heating instead of fission in the fuel itself.This essentially decouples the fuel temperature from the fission rate.This outcome is a criti- cally important feature of the design to maximize utility for the modeling community; experiments can be performed where temperature gradi- ents are less than 10 K/mm within the sample.Typical integral tests are over an order of magnitude larger. The increased burnup rate that can be induced inside the fuel volume without resulting in extreme and non-representative temperature profiles and the thermal flux available in HFIR also provide another key advantage. Fuels can reach burnups typical to those of commercial light water reactors at discharge in roughly one calendar year (six cycles). Lower burnup capsules can be independently removed at shorter intervals.This means that researchers will be able to acquire the first postirradiation examination data far more rapidly than is possible for most integral tests.