The U.S. Department of Energy's Office of Environmental Management is once more opening the Hanford Site's B Reactor National Historic Landmark in Washington.

U.S. Department of Energy is hoping more history and engineering enthusiasts, as well as science aficionados, will again flock to tour the B Reactor National Historic Landmark, according to a May 2 news release. B Reactor was the world's first full-scale plutonium production reactor.

"It is so exciting to be back this year with a full public tour schedule," Colleen French, DOE program manager for the Manhattan Project National Historical Park at Hanford, said in the release. "We have tours six days a week through the summer, including the holiday weekends, and they are already going out completely full. I'm not sure who is more excited — the visitors coming in the door or the staff and docents!"

This year's public tour season at B Reactor began the first week of April for open free registration, the release reported. B Reactor and other Manhattan Project National Historical Park facilities expect to be open for public tours through Nov. 18. 

Visitors with disabilities are accommodated during the tours, according to the release. Each tour is about four hours of a guided experience, as well as the opportunity for self-exploration and reflection.

Manhattan Project National Historical Park was established in 2015 for the preservation and interpretation of the Manhattan Project and the dawn of the atomic age, the release reported. Tours are jointly administered by the DOE and the National Park Service as part of the DOE's national park mission to own and maintain historic facilities for public access. Tours at Hanford's B Reactor began in 2009.

Hanford Site and its B Reactor are part of DOE historic properties, that also include historic facilities in Oak Ridge, Tennessee and Los Alamos, New Mexico, where cleanup work is underway.