The NIST Center for Neutron Research in Gaithersburg, Md. (Photo: NIST)
In the 13 months since a fuel element failure triggered a scram of the research reactor at the National Institute of Standards and Technology’s NIST Center for Neutron Research (NCNR), the event and its causes have been scrutinized by both NIST and the Nuclear Regulatory Commission.
Initial conclusions from an NRC special inspection released on March 16 confirm that while public health and safety was maintained during and after the event, and doses to reactor facility staff were well below regulatory limits, a safety limit was violated when the temperature of the fuel cladding of a single fuel element in the 20-MWt research reactor reached a temperature high enough to partially melt the element.
The TRIGA II research reactor at Slovenia’s Josef Stefan Institute. (Photo: Josef Stefan Institute)
The Berkeley, Calif.-based startup Deep Isolation has contracted with Slovenia’s radioactive waste management organization ARAO to conduct a feasibility study on the use of deep boreholes to dispose of the country’s spent research reactor fuel.
A rendering of Ultra Safe Nuclear Corporation’s micro modular reactor as proposed for construction on the University of Illinois at Urbana-Champaign campus. (Graphic: USNC)
The U.S. state with more nuclear power plants than any other—Illinois—has no operating university research reactors. A team at the University of Illinois at Urbana-Champaign (UIUC) intends to reverse that situation and construct a high-temperature gas-cooled microreactor. If the team's plans go ahead, the first new U.S. university research reactor deployment in about 30 years could also support commercial advanced reactor deployment.
Idaho’s ATR Critical Facility undergoes a digital control system upgrade.

Reactor operators Craig Winder (foreground) and Clint Weigel prepare to start up the ATRC Facility reactor at Idaho National Laboratory after a nearly two-year project to digitally upgrade many of the reactor’s key instrumentation and control systems.
Photos: DOE/INL
At first glance, the Advanced Test Reactor Critical (ATRC) Facility has very little in common with a full-size 800- or 1,000-MW nuclear power reactor. The similarities are there, however, as are the lessons to be learned from efforts to modernize the instrumentation and control systems that make them valuable assets, far beyond what their designers had envisioned.
One of four research and test reactors at Idaho National Laboratory, the ATRC is a low-power critical facility that directly supports the operations of INL’s 250-MW Advanced Test Reactor (ATR). Located in the same building, the ATR and the ATRC share the canal used for storing fuel and experiment assemblies between operating cycles.
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.