of the Hanford production reactors were entombed ("cocooned") to allow the radioactive materials to decay, and the surrounding structures removed and buried. This involved the removal of hundreds of tons of asbestos, concrete, steel and contaminated soil. The pumps and tunnels were dug up and razed, as were the auxiliary buildings. What was left were the core and shields. These were sealed up and a sloped steel roof added to draw off rainwater. Cocooning of CReactor commenced in 1996, and was completed in 1998. DReactor followed in 2002, FReactor followed in 2003, DRReactor in 2004. and HReactor in 2005. N Reactor was cocooned in 2012, and KE and KW in 2022. The exception was B Reactor, which was listed on the National Register of Historic Places in 1992. Some historians advocated converting it into a museum. It was designated a National Historic Landmark by the National Park Service on August 19, 2008, and on November 10, 2015, it became part of the Manhattan Project National Historical Park alongside other sites at Oak Ridge and Los Alamos. The United States Department of Energy (DOE) offers free guided tours of the site which can be reserved via the department's website, and are open to all ages. Between 2009 and 2018, approximately eighty thousand people visited the site, bringing an estimated annual tourist income of two million dollars to the surrounding area. Later operations Although uranium enrichment and plutonium breeding were slowly phased out, the nuclear legacy left an indelible mark on the Tri-Cities. Since World WarII, the area had developed from a small farming community to a booming "Atomic Frontier" to a powerhouse of the nuclear-industrial complex. Decades of federal investment created a community of highly skilled scientists and engineers. As a result of this concentration of specialized skills, the Hanford Site attempted to diversify its operations to include scientific research, test facilities, and commercial nuclear power production. When GE announced that it was ending the contract to run the Hanford Site in 1963, the AEC decided to separate the contract among multiple operators. The contract to run the research laboratory at the site was awarded to the Battelle Memorial Institute of Columbus, Ohio, on May 28, 1964, and the laboratory became the Pacific Northwest Laboratory on January 4, 1965. In 1995 it achieved national laboratory status and became The Pacific Northwest National Laboratory. Battelle's contract allowed it to perform research for