(9 am. – promoted by ek hornbeck)
The risk to workers might be greater than previously thought because melted fuel in the No. 1 reactor building may be causing isolated, uncontrolled nuclear chain reactions, Denis Flory, nuclear safety director for the UN’s International Atomic Energy Agency, said at a press conference in Vienna.
Nuclear experts call these reactions “localized criticality,” which will increase radiation and hamper the ability to shut down the plant. The reactions consist of a burst of heat, radiation and sometimes an “ethereal blue flash,” according to the U.S. Energy Department’s Los Alamos National Laboratory web site.
Uncontrolled nuclear chain reactions!
Just like an atomic bomb, only smaller!
And what could happen if the meltdown continues, and all the plutonium in Reactor #3 melts into a blob that’s bigger than critical mass?
3 comments
… its just a higher concentration in the “mixed oxide” fuel rods (such an innocuous sounding name!) … during operation, a small percentage of the Uranium 238 converts to Plutonium 239.
I have seen Wikipedia machine suggestions (so take them for whatever that is worth) that thorium fuel cycle reactors produce less total long lived radioactive
waste and the Uranium 233 produced in the Thorium fuel is contaminated with Uranium 232 which is not possible to chemically separate, and is a gamma emitter and easier to detect with passive detectors. And in the scenario in question here ~ the mixed oxide fuel used to destroy some of the plutonium ~ since a thorium fuel cycle is more efficient at consuming plutonium.
Thorium fuel itself needs no enrichment, but since it is not itself fissile, it needs a radioactive seed fuel.
The two biggest cited drawbacks of thorium are that there are aspects of the thorium that make are a bad fit to Light Water Reactors, but advocates of Molten Salt and similar reactor designs would argue the problem there is the LWR technology ~ and it seems to me if the risks of Light Water Reactors were to be priced in, we’d have a lot fewer of them.
The second drawback is that because the Thorium is not fissile, it cannot be used to make a bomb, so it has not attracted the attention of atomic weapons research that Uranium and Plutonium have received.
Less often cited, the discussion of proliferation risk and long lived radioactive waste is about how the thorium fuel cycles look relative to current enriched uranium fuel cycles. I’d wager quite a bit that the proliferation and long lived radioactive waste from wind turbines, Stirling concentrated thermal solar power stations, and run-of-river (that is, damless) hydro are not only relatively less than uranium but very, very low in absolute terms.