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I don't think it's true to say no new heat is being added. The uranium fission process has stopped, but there are secondary radioactive elements created by the
by jeza 16y ago
I don't think it's true to say no new heat is being added. The uranium fission process has stopped, but there are secondary radioactive elements created by the decay of uranium. These elements will continue to decay, as such the core is still producing the heat. Though eventually this heat will decline to a safe level, provided there isn't a meltdown beforehand.
The design oversight seems to be that they depend on external AC power or diesel generators for backup. Surely there should be an emergency generator that can run off the heat that the core still produces in order to at least partially operate the cooling system. Much like aeroplanes have a small dynamo that runs off a tiny wind emergency wind turbine so they can still operate the hydraulics with no engines running. A saving grace in the case of Gimli Glider (http://en.wikipedia.org/wiki/Gimli_Glider http://en.wikipedia.org/wiki/Gimli_Glider).
- redthrowaway 16y agoAh, thanks for the explanation. As I said, that was just what I had read. I appreciate the further info. What you said makes sense, and explains why steam pressure is still building.
- jeza 16y agoNo problem. Further to my comments about the design, I read in another story linked to on HN that generation III reactors now use convection based cooling. I gather this means the water is taken elsewhere as steam to cool then returns via gravity to the core. Therefore you wouldn't have this same kind of issue with a modern reactor.
- redthrowaway 16y agoInteresting. That seems like a smart way of doing it.