Criticality testing milestone for Westinghouse's eVinci reactor

The test was completed at the Nevada National Security Site in the US, on Monday at 10:39 local time.

It was carried out in partnership with the Los Alamos and Idaho National Laboratories at the National Criticality Experiments Research Center, a National Nuclear Security Administration facility at the Nevada site.

Westinghouse Chief Technology Officer Lou Martinez Sancho thanked the company's partners for their support, including the US Department of Energy, and said: "This zero-power criticality milestone reflects Westinghouse’s heritage of innovation and pushing to the next frontier of nuclear."

Criticality is the point at which a nuclear reactor sustains a controlled, self-supporting chain reaction. Zero-power criticality is intended to validate the models and core design assumptions of the technology rather than generating heat or power.

Westinghouse said the achievement was part of its "rapid product development philosophy, which combines testing, modelling, simulation and design improvements to accelerate technology maturation while reducing technical risk".

The eVinci is a heat pipe-cooled microreactor which can produce up to 5 MWe with a 15 MWt core design. The TRISO-fuelled reactor core is designed to run for eight or more full-power years before refuelling, and the factory-built and assembled reactor can be shipped in a container to provide versatile, scalable energy for a variety of applications, including defence and in space.