U.S. NUCLEAR TEST REACTOR GETTING MAJOR OVERHAUL

Scientists in Idaho this summer plan to remove the 62,000-pound stainless steel lid on one of the world’s most powerful nuclear test reactors for a rare internal overhaul.

The Advanced Test Reactor

at the Idaho National Laboratory is being refurbished and improved with new components and experimental capacity, the scientists said in interviews last week.

The nine-month, $170 million effort, called a core internals change-out, started last month and is scheduled to be finished around the end of the year.

An additional $100 million has been spent over the last three years on replacing external equipment to keep the test reactor going.

Experiments at the reactor help the U.S. Navy’s nuclear-powered war fleet stay at sea longer, bolster NASA’S space exploration, and advance life-saving medical treatments. The reactor also plays a key role in the effort to keep commercial nuclear power plants running longer and creating new and safer reactors to reduce greenhouse gas emissions.

“ATR is an absolutely beautiful reactor,” said Sean O’kelly, associate lab director in charge of the test reactor. “There has never been one like it on the planet.”

The reactor is configured so it can run multiple tests simultaneously. Some of the best testing slots face a decadelong wait for room to run experiments, and other slots are booked years in advance.

The ATR is unique because unlike commercial nuclear reactors that produce heat that’s turned into energy, the ATR produces neutrons so that new materials and fuels can be tested to see how they react in high-radiation environments. The test reactor’s unique cloverleaf design includes a core that’s surrounded by beryllium metal to ref lect the neutrons.

But all those neutrons puts wear on the internal parts of the test reactor, meaning it would lose the ability to conduct experiments if it is not refurbished.

The reactor’s designers foresaw that problem and created a reactor with internal components that can be periodically replaced. The current change-out is the sixth since the reactor started operating in 1967 and the first in 17 years.