Normally, once a building’s slated for demolition, people stop spending money on it. You don’t put a new roof on a house the month before the excavator shows up.<\/p>\n
So it’s a little funny that the government-owned company cleaning up the old Dounreay nuclear site, on the far north coast of Scotland, went looking for a painter last year. The job was touching up rust on a giant steel ball that’s officially earmarked to be torn down. The Northern Times<\/em> reported the contract could run up to \u00a3500,000, and that the ball hadn’t been painted in 25 years.<\/p>\n It’s a patch job, to be fair. The operator, Nuclear Restoration Services (NRS), said only the rusty spots crews can reach from the ground would get paint, and that the rust doesn’t affect the structure. I haven’t been able to confirm whether the brushes have come out yet.<\/p>\n Why bother? It’s pretty simple, really. The ball’s still doing its job, because the reactor inside it still isn’t empty. An NRS spokesperson told the paper the sphere remains “an integral part of the way we protect people and the environment” while that reactor gets taken apart.<\/p>\n The sphere is 135 feet across. Local archivists say it weighed 1,500 tons when it went up in the mid-1950s (British tons, which run a little heavier than ours) and that it’s held together by more than two miles of welded seams. Each seam was checked with radiography, which is basically an X-ray for steel. It was the biggest sphere in Europe when it was finished, and it was built to be airtight.<\/p>\n Inside is the Dounreay Fast Reactor. It went critical in November 1959, and in October 1962 it started feeding Britain’s national grid, which made it the first fast reactor anywhere to do that, according to World Nuclear News. It made around 14 megawatts of electricity, roughly enough for Thurso, the little town down the road. It switched off for good in March 1977.<\/p>\n If “fast reactor” sounds like jargon to you, here’s the short version. Most reactors slow their neutrons down with water, because slow neutrons are better at splitting uranium. A fast reactor lets them fly, which rules out water as a coolant, so liquid metal goes in instead. Dounreay’s was also a breeder, meaning the core sat inside a blanket of plain natural uranium, and neutrons escaping the core would turn some of that uranium into plutonium. The goal was to make more fuel than the reactor burned. In 1950s Britain, when uranium was hard to come by, that was a pretty great pitch.<\/p>\n Quick note, since the two get mixed up: Dounreay had a second, much bigger fast reactor next door, called the Prototype Fast Reactor, and that reactor shut down in 1994. The ball’s reactor had already been retired for 17 years by then.<\/p>\n The liquid metal in the ball’s reactor was NaK, a sodium-potassium alloy that stays liquid at room temperature and reacts vigorously with air or water, to the point where it can catch fire. You can’t exactly drain that into a bucket. On top of that, the fuel’s design let the coolant touch the fuel directly, and the NaK soaked up a huge load of radioactive cesium.<\/p>\n Getting rid of it took a chemical plant built just for the job, plus about four years. Crews lifted about 15,000 gallons (57,000 liters) out of the main cooling loop in 354 small batches, neutralized it and filtered the cesium out, which left roughly 22,000 tons of salty water. Then they spent about four more years chasing residue out of the pipework. According to the government’s own account of that job<\/a>, that meant drilling into parts of the reactor by remote control, working from original drawings that apparently no longer matched what decades of modifications had left behind. If you’ve ever renovated an old house, you know the feeling, just without the radiation.<\/p>\n This is where it gets slow. When the reactor shut down, most of the fuel in the core came out, but almost 1,000 breeder elements (stainless steel casings filled with that natural uranium) were found swollen and jammed in place. That was about two-thirds of them. The official releases I’ve read just say “swollen and jammed.” Metal swelling after years of neutron bombardment is a well-known headache in fast reactors, so that’s the likely culprit, but I haven’t seen the site spell out the cause.<\/p>\n The cleanup basically stalled for 20 years after that. The elements were sitting in all that liquid metal, so nobody could even get cameras in to look at them until the NaK was gone.<\/p>\n Nine years ago, remote tools finally started reaching down into the reactor to cut the elements free and lift them into a shielded cask (the British call it a flask). The estimate back then was under three years. About two years in, roughly half were out. It seems fair to assume the easiest ones went first.<\/p>\n So how’s it going now?<\/p>\n According to NRS’s latest progress report to the Dounreay Stakeholder Group<\/a>, crews moved 30 breeder elements out of the reactor in the fiscal year that ended in March. Those 30 hit the target, which the site reached on February 12, but they fell short of the 42 it had set as a stretch goal. Every other operating and enabling target at Dounreay finished at stretch. It isn’t hard to guess where the site’s struggling.<\/p>\n The equipment needed fixing, too. The elements go from the reactor into a shielded processing cell called D2160, where they’re cut open and cleaned up before the uranium gets packed off to Sellafield, England’s big nuclear site. Transfers into that cell were paused while its manipulator arm and the machine that strips off the steel casings were repaired. While the cell was down, crews sped up drilling work inside the reactor to free trapped fuel. The report expected moves to restart in April, and at an April 22 meeting, Frederic Stalin, NRS Dounreay’s portfolio and support director, said May.<\/p>\n NRS hasn’t published a fresh count of how many elements are still inside. The last public tally I can find says half of them were out, and that’s from the fall of 2019. Frankly, 30 a year sounds glacial. But every element left in there is radioactive, stuck and reachable only by remote tools, so I’d rather they take their time.<\/p>\n Nobody’s put a date on that yet, so if you were hoping to watch it come down, you’ll be waiting a while. The Nuclear Decommissioning Authority’s business plan for 2026 to 2029<\/a>, published March 16, gives Dounreay until the 2027\u201328 fiscal year to get the breeder out of the reactor and into interim storage. The plan doesn’t include a line for demolishing the sphere. Every big end date for the site reads TBD, because Dounreay’s lifetime plan is under review, and a UK procurement notice published in July shows NRS brought in outside help for a technical review of that plan.<\/p>\n That’s not a huge surprise. A heritage study once had the sphere coming down by 2032, and local papers reported a couple of years ago that cleanup of the whole site had slid from the 2030s to the 2070s. The order of work doesn’t leave much room, either. The breeder has to come out before crews can clean and remove the reactor and its roughly 5.6 miles (9 kilometers) of cooling pipe, and the sphere is there to seal all of that in until then.<\/p>\n Some countries keep their reactor spheres, for what it’s worth. A 157-foot steel ball around an Italian reactor<\/a> is listed heritage and staying put. Dounreay’s operator looked at saving its sphere too, and the heritage report that ruled it out concluded that “metal shells will never be 100% clear of radioactive contamination,” according to New Civil Engineer. I don’t think a coat of paint changes that.<\/p>\nSo what’s inside the ball?<\/h2>\n
The uranium is still in there<\/h2>\n
So when does the ball come down?<\/h2>\n