US nuke start-up marks mini-reactor breakthrough

A nuclear start-up working on mini-reactors for the US military has announced a crucial first step in producing a model that could be deployed at bases and other strategic sites within a few years.

Antares said Thursday that it had achieved initial criticality for its Mark-0 prototype, meaning it triggered a controlled, self-sustaining fission chain reaction for producing electricity.

It said it was the first private company to achieve the breakthrough for smaller reactors, which countries are increasing considering to supplement their shifts to low-carbon energy grids.

The Mark-0 is one of 11 microreactor projects selected by the US Energy Department as part of an initiative to bring several models to criticality by this year’s July 4 celebrations marking the country’s 250th anniversary.

US Energy Secretary Chris Wright hailed an “important milestone.”