By Editors of Power Engineering

The American Nuclear Society dedicated the Idaho National Laboratory’s Advanced Test Reactor Complex as an ANS Nuclear Historic Landmark.

The complex housed the original Materials Testing Reactor built in 1952, the Engineering Test Reactor in 1957 and the Advanced Test Reactor in 1967.

“The INL Advanced Reactor Complex has valuable history in nuclear energy research, safety, and security,” ANS President Andrew Klein said. “The work performed at the complex today will help us meet current nuclear challenges and develop future advanced reactor technologies.”

The MTR was the first light water reactor to operate using plutonium fuel, demonstrating the viability of the closed nuclear fuel cycle. The work performed at the MTR supported in-core testing of materials and fuels in a nuclear reactor radiation environment and supported development of the first nuclear-powered submarine, the USS Nautilus, that launched in 1954.

In 1957, the ETR began operation as the largest and most advanced test reactor in the world with expanded capabilities. The U.S. Navy used the ETR to simulate the pressures, temperatures, and chemistry of pressurized water reactors for power and propulsion with four times the MTR flux levels.

Today, the ATR remains the largest test reactor in the world with a unique serpentine fuel arrangement. The available experimental space of the ATR is shared by the U.S. Department of Energy, commercial users, other nations, Nuclear Science User Facilities members, and the U.S. Navy. It is still revered as the nation’s premier resource for fuels and materials irradiation testing, nuclear safety research, and nuclear isotope production.