A figure from the “Multistep Coulomb excitation of 64Ni” that shows the time-of-flight difference between the projectile and target recoils as a function of scattering angle measured with the CHICO2 detector. A clear separation between the Ni-64 (bottom) and Pb-208 (top) ions is observed. (Credit: Physical Review C/American Physical Society)
A study published recently in the American Physical Society journal Physical Review C reveals new findings about the strong nuclear force, the mysterious fundamental force that holds together the protons and neutrons of the atomic nucleus. Experiments conducted at Argonne National Laboratory have shown how the round, heavy nuclei of the nickel-64 isotope (containing 28 protons and 36 neutrons, making it the heaviest stable Ni isotope) changed into one of two shapes—either like a doorknob or a football—depending on the amount of energy exerted on it. A summary of the research on the Phys.org website compares the nuclei shape change to popcorn kernels changing shape when heated in a microwave.
On December 2, 1942, a group of 49 scientists led by Enrico Fermi created the world’s first controlled, self-sustaining nuclear chain reaction underneath the University of Chicago’s Stagg Field football stadium. Some of those present went on to found Argonne National Laboratory. (Image: Argonne)
At a moment of global crisis, in a windowless squash court below the football stadium bleachers at the University of Chicago, a group of scientists changed the world forever.
On December 2, 1942, a team of researchers led by Enrico Fermi, an Italian refugee, successfully achieved the world’s first human-created, self-sustaining nuclear chain reaction. Racing to beat Nazi Germany to the creation of an atomic weapon, the team of researchers, working as part of the Manhattan Project, split uranium atoms contained within a large graphite pile—Chicago Pile-1, the first nuclear reactor ever built.
THETA pictured in Argonne National Laboratory’s METL lab. (Photo: ANL)
The Thermal Hydraulic Experimental Test Article (THETA) at Argonne National Laboratory is now operating and providing data that could support the licensing of liquid-metal fast reactor designs by validating thermal-hydraulic and safety analysis codes. The new equipment has been installed in Argonne’s Mechanisms Engineering Test Loop (METL), and its first experiments are supporting data validation needs of Oklo, Inc., by simulating normal operating conditions as well as protected and unprotected loss-of-flow accidents in a sodium-cooled fast reactor.
A screenshot from NuScale's latest video about three current research facilities. (Image: NuScale)
The Department of Energy is funding an independent review of NuScale Power’s safety analysis report (SAR), to be conducted by Ukraine’s State Scientific and Technical Center for Nuclear and Radiation Safety (SSTC NRS), the Portland, Ore.–based small modular reactor developer announced on November 18.
Nine Mile Point (Photo: Constellation Energy)
Exelon Generation has received a grant from the Department of Energy to explore the potential benefits of on-site hydrogen production and has chosen its Nine Mile Point nuclear power plant as the demonstration site, the company announced on Wednesday. (In 2019, Exelon received a conditional commitment from the DOE to co-fund a hydrogen electrolyzer demonstration at a nuclear plant.) Located in Scriba, N.Y., Nine Mile Point consists of two boiling water reactors—the 620-MWe Unit 1 and the 1,287-MWe Unit 2.
Argonne marks its 75th anniversary on July 1. (Image: Argonne)
Seventy-five years ago today, on July 1, 1946, the first U.S. national laboratory was chartered with the singular mission of developing the peaceful uses of nuclear energy. Now, the Department of Energy’s Argonne National Laboratory is one of the nation’s largest science laboratories, working on diverse challenges in energy, climate, science, medicine, and national security.
The 40-year effort to make research reactors safer and more secure has led to the conversion of 71 reactors worldwide from HEU fuel to LEU.

The Ghana Research Reactor-1, located in Accra, Ghana, was converted from HEU fuel to LEU in 2017. Photo: Argonne National Laboratory
In late 2018, Nigeria’s sole operating nuclear research reactor, NIRR-1, switched to a safer uranium fuel. Coming just 18 months on the heels of a celebrated conversion in Ghana, the NIRR-1 reboot passed without much fanfare. However, the switch marked an important global milestone: NIRR-1 was the last of Africa’s 11 operating research reactors to run on high-enriched uranium fuel.
The 40-year effort to make research reactors safer and more secure by replacing HEU fuel with low-enriched uranium is marked by a succession of quiet but immeasurably significant milestones like these. Before Africa, a team of engineers from many organizations, including the U.S. Department of Energy’s Argonne National Laboratory, concluded its conversion work in South America and Australia. Worldwide, 71 reactors in nearly 40 countries have undergone conversions to LEU, defined as less than 20 percent uranium-235. Another 31 research reactors have been permanently shut down.