Award details: ANS’s Nuclear Historic Landmark Award memorializes sites and facilities where outstanding physical accomplishments that advanced the peaceful uses of nuclear energy have taken place. The award recognizes facilities that were in service at least 20 years ago.
The first nine landmarks (which ranged from Chicago Pile 1 to Yankee Nuclear Power Station) were designated in 1985. As of 2025, including these newest recipients, ANS has recognized 101 sites as Nuclear Historic Landmarks.

The NRTS in 1969. To the right, the EBR-II dome is visible. To its immediate left is the EBR-II’s integrated Fuel Cycle Facility. At top left, the mound-shaped Zero Power Plutonium Reactor is visible. In the foreground, between two storage tanks, is the empty land where HFEF would be built. (Photo: NN, May 1969)
A brief history: In May 1969, Nuclear News published its first article on HFEF, covering the high-level conceptual design for the facility. It was to be built beside Experimental Breeder Reactor-II at the National Reactor Testing Station (which would go on to become Idaho National Laboratory). Construction was slated to begin in 1970. At the time, the stated purpose of the facility was primarily to serve EBR-II and the Transient Test Reactor (TREAT), both of which were operated by Argonne National Laboratory.
The facility was also to be made available for work with the Power Burst Facility operated by Phillips Petroleum and the Engineering Test Reactor operated by Idaho Nuclear. HFEF’s ultimate goal was to advance the U.S. liquid metal fast breeder reactor (LMFBR) program by allowing for the postirradiation examination of fuels and materials.
After five years of construction, HFEF entered operation in 1975 and immediately took its place as a national research asset and a flagship facility at Idaho National Engineering Laboratory. According to INL, HFEF is “the largest hot cell dedicated to nuclear materials research in the United States,” and its uses have stretched far beyond its original LMFBR focus. Today, it has evolved into a multiprogram facility that has been leveraged for fuel and components research and development in a wide variety of projects.
Aside from the projects already mentioned, HFEF has notably been used for R&D involving the Fast Flux Test Facility, the Sodium Loop Safety Facility, the Advanced Test Reactor, the Shippingport Light Water Breeder Reactor, and the Commercial Light Water Reactor. HFEF was also used to support the Department of Energy’s efforts to license the Waste Isolation Pilot Plant in New Mexico by providing waste characterization services.
HFEF today: Now 50 years into its life, HFEF is still being used to advance our understanding of nuclear fuels. For a deep dive on the current work being done at the facility, read “Researchers Use One-of-a-Kind Expertise and Capabilities to Test Fuels of Tomorrow,” a new feature in the October 2025 issue of Nuclear News centering on HFEF.