TerraPower LLC, the nuclear energy firm backed by Microsoft founder Bill Gates, has become the first U.S. developer of an advanced nuclear power plant to seek a federal construction and operation permit to test its technology at commercial scale. 

The firm submiited an application in late March to the U.S. Nuclear Regulatory Commission for its Natrium advanced nuclear demonstration project, with plans to begin non-nuclear work at the site of a retiring Wyoming coal plant this summer and nuclear construction once the application is approved.

Bechtel was awarded the EPC contract in 2020 for the project, which is set to be completed possibly by 2028 at an estimated $4-billion cost. About half that cost will be covered by U.S. Energy Dept. funding.

“The TerraPower project is a full-blown nuclear power plant from NRC’s perspective,” agency spokesman Scott Brunell told ENR, noting that the demonstration plant will produce electricity when completed. A demonstration project under NRC’s definition would not produce electricity, he said.

TerraPower in February also selected five suppliers, primarily specialized engineering firms, to support the project to be located in the town of Kemmerer. Contracts were awarded to GERB Vibration Control Systems, Thermal Engineering International, Hayward Tyler Inc., Framatome US Government Solutions and Teledyne Brown Engineering. BWXT Canada was selected last August to design the intermediate heat exchanger. 

The process for awarding contracts for the project is ongoing, TerraPower said.

Construction permit approval generally takes 36 months, but because TerraPower has worked with the NRC through the pre-application phase, it should be faster, Brunell said. The agency will give the company an estimated approval time once it determines it has all the information needed to start a full review, he added.

Advanced Nuclear Boost

Natrium, a TerraPower and GE Hitachi technology, features a 345-MW sodium-cooled fast reactor with a molten salt-based energy storage system that can boost power plant output to 500 MW and allows it to integrate seamlessly with renewable resources, TerraPower said. The non-light water reactor has improved fuel use, enhanced safety features and a streamlined plant layout that requires less overall material to build, the company said.

The project is set to validate the design, construction and operation of the technology at scale. It is part of the U.S. Energy Dept. Advanced Reactor Demonstration Program that received $2.5 billion from the 2021 federal infrastructure law to support design, licensing, construction and operation of two advanced reactor technologies—Natrium and the X-energy Xe-100 reactor. 

TerraPower submitted the application soon after it received on March 19 a 40-page overview from NRC of reactor safety and environmental issues, the latest of similar pre-application assessments the agency provided

"TerraPower will be the first company to submit a commercial advanced nuclear power reactor to the NRC and we feel confident in our timeline to submit this application to the NRC this month," the firm said.

Another advanced nuclear developer, Kairos Power, was the first to submit to NRC an application for a proof of concept for its technology and a second application for a two-unit test version, Brunell said. 

Kairos is taking a different approach to construction by cycling through a build-learn loop to work out the bugs, he said. The company said it is focused on reducing technical risk “through a novel approach to test iteration that often is lacking in the nuclear space.” 

Kairos plans to have a demonstration plant built before 2030.