But how safe would it be to stack up all this radioactive material 50 feet high in a football field?
I don’t think anyone’s proposing to actually store it that way.
I think what we Finns are doing with Onkalo is the way to go, at least in geologically stable areas. It’s an underground long term storage facility where they put the waste in specially designed canisters and seal things up with concrete, 500m underground. Depositing the canisters is handled by robots, so humans don’t have to enter the actual facility once it’s in use.
It’s wild to think that it’s designed to last for 100 000 years. There’s actually been lots of interesting studies (in other countries) on how to make sure people in the far future don’t accidentally wander into these storage sites, when you can’t rely on language at all since it’ll change so much as to be totally unrecognizable in such long time spans. Wikipedia has a neat article on this.
Granted, no one is suggesting to literally store all nuclear waste in a single football field. But it’s an interesting thought experiment that can highlight difficulty of nuclear material & high intensity waste storage.
If you put nuclear material together in a small area, a spontaneous chain reaction occurs. The critical mass is around 15-52 kg for pure uranium, equivalent to a sphere of 11-17 cm in diameter. High activity wastes may not be pure uranium, so critical mass is probably higher, but I’m wondering if that’s even possible physically to put all this waste in a football field without seeing a chain reaction. For safe storage, this is usually diluted, cast in glass cylinder, then barrels spread a bit in the storage area. In these safe-ish storage conditions I expect the storage surface/volume to be significantly larger.
Edit: someone did the math/ and computed height of football field worth of waste, with different assumption (dry casks vs used fuel only vs re-usable fuel only). A football field full of the safer dry cask would be 443 feet high (135 meters).
Finns are leaders with this underground storage, it’s said to be much safer than current surface storage. So Finns definetely deserve a kudos for this waste storage project.
I don’t think anyone’s proposing to actually store it that way.
I think what we Finns are doing with Onkalo is the way to go, at least in geologically stable areas. It’s an underground long term storage facility where they put the waste in specially designed canisters and seal things up with concrete, 500m underground. Depositing the canisters is handled by robots, so humans don’t have to enter the actual facility once it’s in use.
It’s wild to think that it’s designed to last for 100 000 years. There’s actually been lots of interesting studies (in other countries) on how to make sure people in the far future don’t accidentally wander into these storage sites, when you can’t rely on language at all since it’ll change so much as to be totally unrecognizable in such long time spans. Wikipedia has a neat article on this.
Granted, no one is suggesting to literally store all nuclear waste in a single football field. But it’s an interesting thought experiment that can highlight difficulty of nuclear material & high intensity waste storage.
If you put nuclear material together in a small area, a spontaneous chain reaction occurs. The critical mass is around 15-52 kg for pure uranium, equivalent to a sphere of 11-17 cm in diameter. High activity wastes may not be pure uranium, so critical mass is probably higher, but I’m wondering if that’s even possible physically to put all this waste in a football field without seeing a chain reaction. For safe storage, this is usually diluted, cast in glass cylinder, then barrels spread a bit in the storage area. In these safe-ish storage conditions I expect the storage surface/volume to be significantly larger.
Edit: someone did the math/ and computed height of football field worth of waste, with different assumption (dry casks vs used fuel only vs re-usable fuel only). A football field full of the safer dry cask would be 443 feet high (135 meters).
Finns are leaders with this underground storage, it’s said to be much safer than current surface storage. So Finns definetely deserve a kudos for this waste storage project.
For once we’re on the forefront of doing the right thing 😄