Furrowed rows of rocky soil covered with straw are all that remain in the north portion of Hanford's 300 Area, the nuclear reservation's industrial complex a mile north of Richland.
Gone are 60 buildings and 53 contaminated soil waste sites north of Apple Street, a street familiar to Hanford workers because it divides the center of the 300 Area east to west.
Completing the work and replanting the area with native grasses, which will sprout beneath the straw, meets a legally binding Tri-Party Agreement deadline a month early.
"This is what 'all done' looks like," said Larry Gadbois, a scientist for the Environmental Protection Agency, the regulator on the project. "Ten years ago this was a very ugly, old, contaminated industrial area."
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The 300 Area was used for almost 60 years to fabricate uranium fuel for Hanford's production reactors that produced plutonium for the nation's nuclear weapons program. It also was used for research, and almost anything that was done elsewhere at Hanford to produce plutonium was tested first at the 300 Area.
That left highly contaminated buildings for workers to demolish and radioactive and chemical waste buried undocumented in unexpected places.
Hanford's first reactor and the building that supported it are now history.
Before Hanford's B Reactor began irradiating fuel as the world's first full-scale nuclear reactor in September 1944, the Hanford 300 Area's 305 test pile, or reactor, went critical in February 1944, said Chris Strand, Washington Closure Hanford environmental protection lead for decontamination and demolition.
The reactor, one of six small research reactors that would be built in the 300 Area, was used for fuel quality control work into the 1960s, he said.
Hanford's last operating fuel fabrication facility, the 333 Building, was demolished in 2006.
Uranium dust permeated the 57,000-square-foot building, Gadbois said. It also had extensive contamination with beryllium, a metal that can cause an incurable lung disease, and with solvents and acids used in fuel manufacturing.
It was filled with heavy, bulky equipment, including a 160-ton Loewy Extrusion Press that made all the fuel for Hanford's newest reactor, N Reactor, from 1963 to 1987. The fuel it produced could withstand the higher temperatures needed to economically produce steam for electricity at N Reactor's adjacent steam plant and to make plutonium.
Waste sites, where debris and pipelines were buried or contaminants spilled into the soil, presented other challenges north of Apple Street.
"Given the secrecy of the whole project, you would not know what you would come across," said Rob Voeks, the Washington Closure subcontract technical representative.
Workers digging just outside the foundation of the 314 Building turned up four small vials with remnants of a silvery powder buried about three feet deep. Tests detected mercury in the powder.
But more surprising to Voeks was finding drums of radioactive waste buried underneath the 306 Building as workers were demolishing the slab the building was constructed upon.
"There are places in a million years you would not expect anything," said Gary Snow, Washington Closure director of decontamination and demolition.
The area north of Apple Street also included one of Hanford's earliest waste burial grounds, 618-1, which was used from 1945 through 1951 for debris from 300 Area work. Several buildings had been constructed over the top of parts of it after 1951.
Workers dug up 52,000 tons of material, including contaminated soil, metal pipe, crucibles, laboratory glassware, drums of contaminated equipment and several bottles that still held liquid or powder.
Workers most recently finished digging up 8,000 feet of piping up to three feet in diameter used in the sewer system for laboratory process waste. One line was plugged with yellowcake, a concentrated uranium powder.
Considerable progress on environmental cleanup also has been made south of Apple Street, Snow said.
The 300 Area once had 167 buildings to be demolished, not counting some that will be retained for use by Pacific Northwest National Laboratory. Just 19 remain to be torn down. All but one are planned to be demolished by the end of the year.