X-energy, Oklo, Terrestrial Secure NRC Approvals

On May 18 the Nuclear Regulatory Commission completed an environmental assessment for the Long Mott Generating Station and issued a finding of no significant impact for the construction permit application. The project is a collaboration between X-energy and Dow to site four Xe-100 high-temperature gas-cooled reactors at Dow’s Seadrift, Texas manufacturing facility to supply electricity and high-temperature industrial steam.

The environmental review finished in under one year after pre-application engagement and a submittal that focused NRC reviewers on site-specific issues rather than basic design questions. A finding of no significant impact permits the NRC to proceed without preparing a full environmental impact statement for the construction permit application.

The NRC approved Oklo’s principal design criteria topical report for the Aurora reactor in Idaho. The approved document establishes fundamental safety, reliability and performance requirements and may be referenced in future licensing submissions. The NRC completed that review on an accelerated schedule.

Terrestrial Energy received NRC approval of its postulated initiating events topical report for its integral molten-salt reactor, the IMSR. That report identifies and evaluates events that could challenge safe plant operation and contributes to the safety case for licensing. The approval follows an earlier NRC acceptance of the reactor’s principal design criteria.

Curtiss-Wright moved from design to prototype manufacturing for two systems intended for the Xe-100: the helium circulator and the reactivity control and shutdown systems. The helium circulator moves helium through the reactor core to transfer heat to the power and steam systems. The reactivity control and shutdown systems provide independent methods to regulate power and shut down the reactor.

Producing physical prototypes allows testing and validation of component performance and helps identify manufacturing and integration issues before full production. Curtiss-Wright’s work supports X-energy projects, including the Dow collaboration in Texas.

Topical reports are technical documents that define design criteria or analyze safety scenarios and can be cited in subsequent NRC filings. An environmental assessment is a site- and project-specific review that determines whether a proposed action would have significant environmental effects; a finding of no significant impact allows the NRC to proceed without an environmental impact statement.