Fluor will provide engineering, design and development services for the Washington plant, which is intended to contain X-Energy’s Xe-100 modular nuclear reactors. The companies did not disclose financial terms.

The agreement extends an existing X-Energy–Fluor contract supporting a separate nuclear project in Texas. It also advances X-Energy and Amazon.com’s effort to deploy 5 gigawatts of nuclear energy by 2039. Fluor shares were up about 1.7% at $45.72.