Demolition is usually the simple half of cleaning up an industrial site. You knock the building down, you haul the pieces to a landfill, and the hard part is whatever soaked into the dirt underneath. Hanford does plenty of that. Crews there dropped a 175-foot exhaust stack in February.<\/p>\n
But the reactors themselves get the opposite treatment. Nobody knocks them down. Somebody builds a brand new building around the old one, seals it shut and walks away for most of a century.<\/p>\n
If you haven’t had reason to think about Hanford before, it’s the site in eastern Washington where the government made plutonium for the bomb program, starting in 1943. Nine reactors went up along the Columbia River, the plutonium work left 56 million gallons of waste in underground tanks, and there’s now a furnace on site turning that waste into glass<\/a>.<\/p>\n Seven of those nine reactors are sitting inside sealed enclosures right now. The Department of Energy<\/a> calls it interim safe storage. Everybody at the site calls it cocooning. That’s a friendlier word than the job deserves.<\/p>\n The newest one covers the K East Reactor, and it’s the one worth looking at, because it isn’t a steel roof bolted onto the old concrete walls. It’s a separate building standing more than 120 feet tall (about 37 meters) and more than 150 feet wide, with the sealed reactor inside it and a gap of open air in between.<\/p>\n Crews backfilled and compacted roughly 34,000 cubic yards of sand and gravel around the reactor to level the ground, then poured a concrete foundation 6 feet thick to carry the load. The first steel columns went up in mid-May 2022, the heaviest of them weighing 28 tons apiece (about 25 metric tons). Siding went onto the walls and the roof through that summer. The cocoon came in ahead of schedule and under budget. You don’t get to write that sentence about Hanford very often.<\/p>\n It’s also cheap, at least by the standards of anything with the word nuclear attached. Mark French, a Department of Energy manager at the site, told the Associated Press that the two enclosures in the K Area would run less than $10 million each. That’s office building money for a building nobody is ever going to work in.<\/p>\n Because of what’s still sitting in the middle of it. K East ran from 1955 to 1971 making plutonium, and it wasn’t deactivated until 1998. The core is radioactive enough that taking it apart today would be a far worse job than taking it apart later, and there’s no way to hurry that along. Radioactivity decays on its own schedule. So the plan is to keep the box weathertight until the readings come down, and Hanford’s rules allow the surveillance to run for as long as 75 years before anyone has to decide what final disposal looks like.<\/p>\n Which means the building has to outlast the problem. That’s a strange thing to ask of a steel shed, and it isn’t a Hanford invention either. There’s a 240-megawatt reactor under a grass mound in Nebraska<\/a> that’s been waiting the same way since 1969. A retired commercial reactor from Oregon got barged 270 miles up the Columbia and dropped in a pit<\/a> on the same reservation. Waiting is the American answer to this problem, and burying is the runner-up.<\/p>\n Six other Hanford reactors were cocooned between 1998 and 2012, some of them by putting heavy steel roofing over the existing concrete walls instead of raising a whole new structure. Either way the job is the same: strip the hazardous material out, knock down everything attached, seal every opening in the reactor building.<\/p>\n Somebody does, on a written schedule. The outside gets walked every year, roofing and siding and flashing, plus radiological monitoring around the perimeter. The inside works differently. Hanford’s Long-Term Stewardship Program<\/a> currently runs internal surveillances at K East on a six-year interval, and on a ten-year interval at the six older cocoons.<\/p>\n That number has already moved once. When the enclosure was going up, the Energy Department described the design as allowing a routine interior visit every five years. Mark French, a manager at the agency, told the Associated Press what those visits are actually for: making sure nothing’s leaking, and making sure rodents and birds haven’t moved in. I can’t find a public document explaining the shift from five years to six, and my read is that it’s an administrative call rather than anything the reactor did.<\/p>\n The first full inspection happened in the summer of 2024, and the best part is what the crew did about the roof. You can’t send someone up a ladder in there. A team from Hanford Mission Integration Solutions<\/a> flew a drone into the gap between the steel enclosure and the old reactor building, then used it to look over the reactor’s roof and outer walls, and the roof of the enclosure above them. Joy McCrea, the contractor’s environmental field support director, said the drone gets them a view of the roof “while keeping everyone safely on the ground.”<\/p>\n I like that detail more than any of the dimensions.<\/p>\n You put up a 120-foot box so people don’t have to stand next to a reactor, and then you send in a drone so they don’t have to stand next to the box. The technicians on that trip were also there to confirm nothing had leaked out of the sealed core, and nothing had.<\/p>\n The eighth cocoon has been coming for years. Crews sorted and pulled radioactive debris out of the K West fuel storage basin, a concrete pool 125 feet long and 65 feet wide holding 1.2 million gallons of water, pumped the water out, then filled the thing with about 6,500 cubic yards of grout to lock down whatever was left on the bottom. The stack came down in February. It was the tall thing standing between heavy equipment and the basin.<\/p>\nThe gravel came before the steel<\/h2>\n
So why not knock the reactor down?<\/h2>\n
So who checks on it?<\/h2>\n
K West is the last one, and it’s been slow<\/h2>\n