FLiBe—a mixture of lithium fluoride and beryllium fluoride—is not an off-the-shelf commodity. The Department of Energy suspects that researchers and reactor developers may have a use for the 2,000 kilograms of fluoride-based salt that once ran through the secondary coolant loop of the Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory.

By late 1960, when the U.S. Atomic Energy Commission authorized plans to build a Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory, the lab already had about 13 years of experimentation with molten salt reactors under its longest-serving lab director, Alvin Weinberg. The MSRE operated from 1965 to 1969, proving that molten salt reactors could operate reliably, and with alternatives to uranium-235 too.

This year’s American Nuclear Society Annual Meeting was filled with great content, some of which was covered in the August issue of Nuclear News (beginning on p. 22). One of the meeting’s executive sessions, “Bringing Nuclear History Forward,” focused on advanced reactor (AR) history and was well attended. The United States—along with many countries around the world—is turning to nuclear to combat climate change. Part of this is funding new and innovative companies to create first-of-a-kind nuclear reactors to provide abundant and clean power. Looking at the current designs of interest to the community brings up interesting comparisons to the test and experimental reactors of the past. Test reactors like the Experimental Breeder Reactor-II (EBR-II), the Fast Flux Test Facility (FFTF), Peach Bottom, Fort St. Vrain, Germany’s AVR, and others now are more important than ever in providing insight, data, and operational lessons learned to develop the next generation of reactors.

The Molten Salt Reactor Experiment (MSRE) facility is one of hundreds of old, contaminated buildings at Oak Ridge National Laboratory and the Y-12 National Security Complex in Tennessee that are slated to be taken down.