The world's largest source of neutrons for science research just got a major new upgrade

“The design of the new core of the PIK reactor, developed by Rosatom, is optimal in terms of its consumer characteristics,” said Senior Vice President for Scientific & Technical Activities at TVEL Alexander Ugryumov. “It provides efficient operating modes and satisfies both modern international requirements for nuclear research facilities and requirements in the field of atomic energy use, which is a priority for the functioning of the International Centre for Neutron Research. In addition, long reactor campaigns will help reduce fuel consumption and, accordingly, reduce the operating costs of the reactor,”

The upgraded PIK reactor, which went online in 2021, is a pressurized water reactor that uses light water — that is, water that has less deuterium than occurs naturally on Earth — as a coolant and heavy water — water with higher levels of deuterium isotopes than normal — as a reflector.

Neutron beams that escape during reactions in the reactor are channeled into different research stations for use in different areas of nuclear research from physics to medicine.

Turbulent history for the PIK reactor

The safety of the new fuel powering the reactor is a major part of its importance, as the design for PNPI's PIK reactor was originally produced in the 1970s, with construction continuing throughout the 1980s. In 1986, the reactor complex was about 70% finished when the Chernobyl power plant disaster brought construction to a halt.

After an extensive Societ review and reactor redesign to ensure its safety, work resumed until 1991, when the collapse of the Societ Union further delayed the completion of the facility. Though the reactor's safety was confirmed by international nuclear engineers from the US, Germany, and other nations in 1992, political disruptions kept the facility from being completed. It was only when the facility was rolled into the newly commissioned Kurchatov Institute Research Center (KIRC) that construction was able to begin again, and in February 2011 start-up complex No. 1 was finished and the reactor was finally turned on for the first time, operating at 100 W.

Afterward, the facility was designated as the future home of the International Center for Neutron Research (ICNR), and the facility was substantially upgraded to make it the largest producer of neutrons for research in the world.

"We are launching a device that, in addition to being a unique installation for carrying out scientific research at an absolutely transcendental level, is also a basic installation for technological breakthroughs, primarily in the field of creating new materials and new technologies in the energy sector, creating fundamentally new drugs and biomedical technologies, in particular, nuclear medicine, of course, agriculture and many other things,” KIRC president Mikhail Kovalchuk said in 2021 when the facility reopened.

Neutrons are surprisingly hard to come by

The upgraded fuel for the PIK research reactor comes at a trying time for both Russia and the world's scientific community when it comes to this kind of advanced research. Russia has faced widespread international ostracization over its invasion of neighboring Ukraine, which has chilled international scientific cooperation.

Meanwhile, at the same time as the PIK reactor was coming online in early 2021, an accident at the National Institute of Standards and Technology's Center for Neutron Research (NCNR) in Maryland took its research reactor offline for more than two years, disrupting neutron scattering experiments crucial to a wide range of research fields.

"We do a lot of research on magnetic materials," Despina Louca, a condensed-matter physicist, told Physics Today back in 2021, "and the neutron is the best probe when it comes to magnetism because of its intrinsic magnetic moment and the very high resolution that neutron techniques provide us with. Because they are highly penetrative, neutrons are also best for determining structures and dynamics in specialized environments, such as those involving magnetic and electric fields.”

The NCNR reactor has undergone an incident review and cleanup operation, with the reactor expected to come back online in the next couple of months, but just as the new reactor upgrade in Russia could be helping researchers get through long-delayed experiments with neutrons, that reactor is effectively restricted to those nations still on friendly terms with Russia, which excludes much of the West and allied countries.