PART 2 So, ROVs. We probably aren't going to use a ROV for our solution as it doesn't suit and they're a pain in the arse quite frankly. To start, I'll addre

PART 2 So, ROVs. We probably aren't going to use a ROV for our solution as it doesn't suit and they're a pain in the arse quite frankly. To start, I'll address the issue with the 'wires' failing. An American company built a ROV that was heavily shielded and was driven via an umbilical. Wireless is hard to use and autonomy is too hard to use as the reactor conditions are unknown. The ROV was a good design and could survive the radiation for a reasonable amount of time, however for whatever reason they used PVC wire sheathes that break down under heavy radiation, and as a result the wires touched and shorted the electronics out, rendering the ROV useless and 'dead'. In terms of why it takes so long and why we can't use an off the shelf version, basically radiation is a bitch. At the base of the reactor vessel, just above the corium, the radiation output is estimated to be around 3000 microsieverts per hour, that translates roughly to a human life expectancy of around 6 seconds, give or take. This amount of radiation causes electronics to fail (transistors commonly), and materials to break down. The breaking down of materials caused the American ROV to die, and another example would be that it can causes greases to harden, which stops motors working. Reactors aren't big spacious areas either, so it's not like we can just deploy a lead (lead weighs a metric shit'tonne) shielded tank to have a look, it's just too big and cumbersome. We decided against using a ROV as it had to be 30kg or less, which is absolutely nothing once you bring in drilling packages and the likes. Also quite often you will be deploying through a hole between the size of your fist up to just smaller than the diameter of your head, so that restricts you hugely as well. You also have material compatability. If you get something stuck you have to be sure that it won't react and cause the reactor to become critical again, which could happen in one of the reactors (can't go into more detail sorry). One last major consideration as too why it takes so long to build and test a ROV to suit. The reactors are under immense thermal stress, and metal likes to bend and warp when it's heating/cooling. You have to build your solution around the worst case scenario. An example would be we went into a boiler tube trying to plug a 1 inch hole from 18m above it using a manipulator arm. That's already hard on its own, but then we discovered the originally 7mm gap we were aiming for was actually now as small as 3.5mm. Trying to develop ROVs and remote solutions is really not easy, the best way I can put it is that this line of work is an art, not a science. That's why it will probably take the best part of a century I reckon to fix this problem.