B Reactor is closed to visitors during roof replacement; Hanford history tours still run

B Reactor — the world’s first full-scale plutonium production reactor and a centerpiece of the Manhattan Project National Historical Park — is closed to public access while DOE replaces its roof and completes other preservation work.

Public access to Hanford’s historic sites is only through DOE-run tours, which require advance registration. Virtual tours of B Reactor and T Plant are available on the park’s website, and the REACH Museum in Richland covers the story in its exhibits.