I’m watching Chernobyl on HBO and they’re describing the different areas of the building after the explosion, some of which they say would kill you within days or weeks due to the high level of radiation. They also talk about how they can’t even use robots to clean the material up because the extreme radiation will shred the circuitry of the robots. So, how on earth are these things constructed in the first place?
In: Engineering
This has little bearing on Chernobyl but most reactors in the world are PWR or BWR (incl. Fukushima), which are basically big steel pressure vessels to hold water under pressure (PWRs under significantly higher pressure). There is a pretty neat (https://www.youtube.com/watch?v=91yVhrSZ5jQ) by russian industry on their production. They are so big that only a few facilities in the world can make them.
The core proper is just some geometrical arrangement of fuel assemblies and control rods placed [in the middle of the vessel](https://cdn.britannica.com/96/102096-004-4018C7BB.jpg). None of the components are significantly radioactive initially. Unused fuel can be held by hand without concern.
Once the reactor has been run though, there is significant radioactivity in the core even after shutdown. Either way, refueling is performed on an open reactor vessel using cranes that handle the fuel assemblies. The water in the vessel is sufficient to shield from radiation coming from the core, but if a used assembly is lifted out of the water, its radiation is dangerous to anyone immediately nearby. Usually the used assemblies are just placed into another pool of water that sits next to the reactors, using the crane.
Latest Answers