A proposed design of the "Natrium" nuclear plant that will be built in Wyoming shared in a PacifiCorps press release. (PacifiCorps)

CASPER, Wyo. — TerraPower, the Bill Gates–founded company that has selected Kemmerer, Wyoming as its preferred site for a new, roughly $4 billion “Natrium” nuclear reactor, said in a press release Monday that it has reached an agreement to collaborate with Japan Atomic Energy Agency (JAEA) on sodium-cooled fast reactor nuclear technology.

“We appreciate the expertise that JAEA will bring to our project, and we are confident that our program will help them as they consider advanced reactors in Japan,” TerraPower President and CEO Chris Levesque said.

The project to build the first 345MWe Natrium plant in Wyoming is something that aims to demonstrate the TerraPower and GE Hitachi technology behind it and TerraPower wants to see more Natrium plants built on the heels of the first project.

The $4 billion Natrium project in Wyoming is being funded through a public–private partnership in which the U.S. Department of Energy is contributing about $2 billion toward construction and licensing costs with TerraPower matching that amount.

The company announced Monday that it had signed a memorandum of understanding with Japan Atomic Energy Agency, Mitsubishi Heavy Industries and Mitsubishi FBR Systems “to share data and resources related to the development of advanced sodium fast reactor (SFR) technology.”

“Japan is known as a leader in developing sodium fast reactors, with experience dating back to the mid-1980s,” the press release said. “TerraPower is interested in technical cooperation with Japanese entities and intends to work with JAEA and Japanese fast reactor industrials for advanced testing of certain components.”

The TerraPower press release said that there are differences between the Natrium technology and previous sodium fast reactors in Japan.

“Notably, the Natrium reactor is a commercial power source that will utilize once-through high-assay low-enriched uranium fuel and is not intended for either breeding fissile material or for working in tandem with a reprocessing program,” TerraPower said.

JAEA President Toshido Kodama said in the press release: “This cooperation with TerraPower will contribute to further development of the U.S.–Japan cooperation on sodium cooled fast reactors. We believe that It can provide a good opportunity for Japan to advance our SFR technologies toward carbon neutrality.”