Where else could you find this kind of energy? At the Nuclear Regulatory Commission (NRC) our power comes from our people. Hardworking Americans who oversee the safe use of nuclear technology that powers communities, revolutionizes medicine, and empowers America.

Learn More

Nuclear History

60 years of headlines from the Advanced Test Reactor

March 24, 2022, 3:01PMANS Nuclear Cafe
Cover of the April 1962 issue of Nuclear News (left), ATR core diagram appearing in October 1969 issue of Nuclear News (center), and cover of the October 1969 issue of Nuclear News (right).

The Department of Energy and Idaho National Laboratory announced this week that the sixth major core overhaul of the Advanced Test Reactor (ATR) is complete, after an 11-month outage that began in April 2021. The ATR was built as a key piece of mission support for U.S. Navy programs and first reached full power in 1969. Today it remains “the world’s largest, most powerful and flexible materials test reactor,” in the words of INL—quite a feat for a reactor that was planned over 60 years ago.

To continue reading, log in or create a free account!

Related Articles

Mark Peters: Building on a strong foundation

July 10, 2026, 3:09PMNuclear NewsLucas Geiger

Summer at the American Nuclear Society carries with it a sense of renewed momentum as the incoming president takes office and starts making plans for the year ahead. This has been particularly...

ICYMI: Counting up INL’s reactors

July 10, 2026, 7:10AMNuclear News

Over the past two weeks, in the “Trivia Tuesday” and “Throwback Thursday” sections of Nuclear News Daily, we have dug into the story of Idaho National Laboratory’s official list of...

DOME: Legacy built, future ready

June 26, 2026, 2:59PMNuclear News

In 2019, a familiar landmark at Idaho National Laboratory was scheduled for demolition. Though striking for both its physical presence and its significance to nuclear history, the containment...