Advanced nuclear reactors no safer than conventional nuclear plants, says science group

A new generation of so-called "advanced" nuclear power reactors that Washington believes could help fight climate change often present greater proliferation risks than conventional nuclear power, a science advocacy group said on Thursday.

President Joe Biden, a Democrat, has made curbing climate change one of the pillars of his administration and has supported research and development for advanced nuclear technologies.

The reactors are also popular with many Republicans. Last October, the month before Biden was elected, the US Department of Energy, awarded $80 million each to TerraPower LLC and X-energy to build reactors it said would be operational in seven years.

Unlike conventional reactors that are cooled with water, advanced reactors are cooled with other materials like molten salt, and are generally far smaller. Backers say they are safer and some can use nuclear waste as a fuel.

"The technologies are certainly different from current reactors, but it is not at all clear they are better," said Edwin Lyman, the director of nuclear power safety at the Union of Concerned Scientists.

"In many cases, they are worse with regard to ... safety, and the potential for severe accidents and potential nuclear proliferation," said Lyman, the author of a UCS report called Advanced' Isn't Always Better which was released Thursday.

Nuclear reactors generate virtually emissions-free power which means conventional ones, at least, will play a role in the effort to decarbonize the economy by 2050, a goal of the Biden administration. But several of the 94 US conventional nuclear plants are shutting due to high safety costs and competition from natural gas and wind and solar energy.

That has helped spark initial funding for a new generation of reactors.

But fuel for many of those reactors would have to be enriched at a much higher rate than conventional fuel, meaning the fuel supply chain could be an attractive target for militants looking to create a crude nuclear weapon, the report said.

And to make fuel for new reactors from today's nuclear waste would require reprocessing. That technique has not been practiced in the United States for decades because of proliferation and cost concerns. Other advanced reactors emit large amounts of radioactive gases which would be another problematic waste stream.

Lyman said money going into advanced nuclear would be better spent on bolstering conventional nuclear plants from the risks of earthquakes and climate change, such as flooding.