Anyone who’s tried to change a light bulb in a two-story foyer knows the bulb isn’t really the problem. Getting up there is. You need a taller ladder, someone to hold it, and a fair amount of faith in both.<\/p>\n
Lithuania’s Ignalina nuclear plant has a much bigger version of that problem. Its operator, a state-owned company that now goes by Altra, needs to cut up equipment sitting high inside the old reactor buildings, in areas where radiation limits how long people can stay. So it’s sending in a robot. And since that robot can’t exactly climb, Altra had a machine modified to lift it.<\/p>\n
Altra said on November 6<\/a> that the machine, a Sennebogen material handler adapted for this job, went through factory acceptance tests at Sennebogen’s plant in Germany the week before. The tests put it through different operating conditions and checked whether its main functions were ready for the work planned at Ignalina. It’s due at the plant at the end of November.<\/p>\n Altra puts its weight at around 40 metric tons. In American terms you’re looking at roughly 88,000 pounds, or about 44 of the tons we use here. Altra also says it’ll be able to work almost 65 feet off the ground.<\/p>\n From the looks of the photos Altra published, the machine started life as a Sennebogen 830 E in demolition trim. It’s sitting inside a heavy steel frame in those shots, and Altra hasn’t said what exactly was modified, so I can’t tell you how much of the stock machine is left.<\/p>\n Ignalina ran two RBMK-1500 reactors, part of the same Soviet reactor family as Chernobyl. Lithuania agreed to close both as a condition of joining the European Union, and the second one went offline nearly 17 years ago.<\/p>\n In an RBMK, the water cooling the fuel boils right inside the reactor, so what comes out the top is a hot mix of steam and water. The drum separators are huge horizontal tanks above the core that split the two, sending steam to the turbines and water back down for another trip. Because that water ran through the core, the separators belong to the plant’s contaminated primary circuit, which is why Altra would rather not have people spending long shifts next to them with a cutting torch.<\/p>\n Ignalina has eight of them, spread over its two reactors. Going by Altra’s figures, each one is close to 98 feet long and almost 10 feet across, and weighs up to about 660,000 pounds, or roughly 330 tons. Add the piping and other connected equipment, and Altra puts the total it plans to remove at around 6,600 tons.<\/p>\n That’s a lot of contaminated steel to cut into pieces small enough to carry out of a building. Altra ranks the separators among the toughest technical jobs of the entire teardown, which seems pretty fair to me.<\/p>\n Just so no one gets the wrong idea, the handler won’t be picking up a 330-ton drum. Its job is carrying the robot that does the cutting.<\/p>\n The robot riding on it is a Brokk, a Swedish make of remote-controlled demolition machine. If you’ve never seen one, picture a compact excavator with no cab and a jointed arm built for breakers, crushers and shears, run by someone holding a remote control a safe distance away. Altra says one of the handler’s main tasks will be lifting a Brokk into spots where it can reach the separators and the structures around them.<\/p>\n Altra has already tested both the Brokk 300 and the smaller Brokk 200 for this project, along with plasma cutting gear, in a setup that recreated part of the real work area. It hasn’t said which model will ride on the handler. If it’s the 300, Brokk’s own specs<\/a> list it at 8,047 pounds before attachments, with a radio remote that works from nearly 1,000 feet away.<\/p>\n So you’ve got a 44-ton machine whose main job is hoisting a robot that, if it’s the Brokk 300, weighs about four tons. That arguably sounds like overkill. But the robot has to sit high up beside a giant steel drum and stay steady enough to break and cut it, and I’d guess a boom with that kind of reach needs a lot of machine underneath it to stay put.<\/p>\n Vytautas Ker\u0161iulis, who heads dismantling and demolition projects at Altra, says the new equipment will let his team “position the BROKK robot closer to the structures being dismantled.” Altra’s whole argument is that people spend less time in radiologically difficult spots while the robot handles the up-close work.<\/p>\n If you read our piece on France’s Superphenix teardown<\/a>, this’ll sound familiar. EDF sent a robot to cut one of the most irradiated pieces in that building from the bottom up before people with a thermal lance finished the job. We’ve also covered an Italian reactor being cut apart under 10 feet of water<\/a>. Remote tools keep showing up in these jobs for the same reason: the less time people spend near the hot stuff, the better.<\/p>\nSo what’s a steam drum separator?<\/h2>\n
The handler is basically a forklift for a robot<\/h2>\n
So who’s actually doing the cutting?<\/h2>\n