Enlarge / The facility seen in this architect's rendering will not be built. (credit: Idaho National Lab )

Nuclear power provides energy that is largely free of carbon emissions and can play a significant role in helping deal with climate change. But in most industrialized countries, the construction of nuclear plants tends to grossly exceed their budgeted cost and run years over schedule.

One hope for changing that has been the use of small, modular nuclear reactors, which can be built in a centralized production facility and then shipped to the site of their installation. But on Wednesday, the company and utility planning to build the first small, modular nuclear plant in the US announced it was canceling the project.

Going small

Small modular reactors take several steps to potentially cut costs. Their smaller size makes it easier for passive cooling systems to take over in the case of power losses (some designs simply keep their reactors in a pond). It also allows the primary components to be built at a central facility and then shipped to different plant sites, allowing a lot of the manufacturing equipment to be reused for all the sites that use the reactors.

Enlarge / The next generation of reactors may be small and modular and use different coolants. (credit: Getty Images )

"The race against climate change is both a marathon and a sprint," declares a new report from the US National Academies of Science . While we have to start decarbonizing immediately with the tech we have now—the sprint—the process will go on for decades, during which technology that's still in development could potentially play a critical role.

The technology at issue in the report is a new generation of nuclear reactors based on different technology; they're smaller and easier to build, and they could potentially use different coolants. The next generation of designs is intended to avoid the delays and cost overruns that are crippling attempts to build additional reactors both here and overseas. But their performance in the real world will remain an unknown until next decade at the earliest, placing them squarely in the "marathon" portion of the race.

The new report focuses on what the US should do to ensure that the new generation of designs has a chance to be evaluated on its merits.

Enlarge (credit: Aurich Lawson | Wikipedia )

Science and the technology it enables have always had a close relationship with warfare. But World War II saw science's destructive power raised to new levels. As the threat of nuclear annihilation remained high for much of the Cold War, many in the public became uneasy with their governments and the scientists working for them.

Many physicists realized that the genie was out of the bottle and recognized this mistrust—or shared it. They created conferences or drafted policies to distance themselves from the nuclear threat. Others tried to spin nuclear technology more positively by focusing on the advances it enabled in energy or medicine. These efforts to reassure the public have continued through today as scientists have taken similar actions for newer, potentially destructive technologies such as gene editing.

During World War II, Sameera Moussa, a relatively unknown Egyptian physicist, was one of the key individuals who tried to use atomic energy for good and made efforts to involve the public in that choice. Her work makes her a worthy role model for women and physicists worldwide, but she’s largely unknown because her crusade for peaceful nuclear power would eventually cost her her life. Moussa was assassinated at age 35 in a case that remains unsolved today.

Enlarge / A German nuclear power plant, which is currently partially closed. (credit: Getty Images )

In 2011, in the wake of the Fukushima disaster, Germany decided to shut down all of its nuclear power. The process was supposed to have ended last year, but it has been extended in response to energy uncertainties caused by the war in Ukraine. As a result, even though renewable generation in Germany continues to climb, the country's carbon emissions have only trended down slowly.

While there's no indication that the US will follow Germany down this path—the Biden administration is actively subsidizing nuclear plants to keep them open—the economics of nuclear power have led to a number of plant shutdowns. It's currently the second-most expensive major source of power, just ahead of offshore wind, with the costs of wind continuing to drop. So there's a significant chance that nuclear's contribution to the US grid will shrink.

A new analysis shows that a drop in nuclear power on the current US grid will mean enough additional pollution to cause over 5,000 deaths each year, and the burden of those deaths will fall disproportionately on Black Americans. But on a future grid where renewables are present at sufficient levels to offset the loss of nuclear, almost all of these additional deaths can be avoided.

Enlarge / An artist’s impression of a deep borehole for nuclear waste disposal by Sandia National Laboratories in 2012. Red lines show the depth of mined repositories: Onkalo is the Finnish one, and WIPP is the US DOE repository for defense waste in New Mexico. (credit: Sandia National Laboratories)

Deep Isolation , a company founded in 2016 and headquartered in California, launched a “ Deep Borehole Demonstration Center ” on February 27. It aims to show that disposal of nuclear waste in deep boreholes is a safe and practical alternative to the mined tunnels that make up most of today’s designs for nuclear waste repositories.

But while the launch named initial board members and published a high-level plan, the startup doesn’t yet have a permanent location, nor does it have the funds secured to complete its planned drilling and testing program.

Although the idea to use deep boreholes for nuclear waste disposal isn’t new , nobody has yet demonstrated it works. The Deep Borehole Demonstration Center aims to be an end-to-end demonstration at full scale, testing everything: safe handling of waste canisters at the surface, disposal, possible retrieval, and eventual permanent sealing deep underground. It will also rehearse techniques for ensuring that eventual underground leaks will not contaminate the surface environment, even many millennia after disposal.