A prototype direct-electrical-heating apparatus has been modified extensively to perform more sophisticated experiments for the out-of-reactor simulation of the in-reactor response of nuclear fuels to applied transients. Improvements have been made to the specimen chamber and the electrical system, and additional instrumentation has been installed. Preliminary results of prooftests indicate that interesting fuel-motion phenomena such as incipient melting, prefailure fuel motion, and gross fuel motion can be studied by means of precise, reproducible, and interrupted experiments.