reported this story, it was easy for nevada senator harry reid to tell us nuclear waste was safer right where it was. leave it on site, where it is. you don t have to worry about transporting it. it saves the country billions and billions of dollars. but japan s crisis has democrats wondering if the effort to keep nuclear waste out of his state is really safer? i truly believe we must rethink how we manage spent fuel. if this was a rail fuel assembly, it would be 13 feet long and weigh over 1,000 pounds. this is a mock-up of a fuel rod assembly, a tightly engineered package of steel tubes, coated with an alloy that protects the highly radioactive uranium pellets inside, except for the height, it s the same as a real fuel rod. even when the fuel is taken out of the reactor, radioactive decay continues.
expand, eventually to rupture, and first to release the gas that s already accumulated within spent fuel, and then as the uranium pellets in the fuel continue to heat up, more and more radioactive material will be squeezed out of the pellets, mostly in the form of cesium 137, which would be a gas at those temperatures. so if the fuel pool has gone dry, that would be a very hard condition to reverse. is there at that point a risk of explosion and do either of those matter at that point? well, there would be presumably a fire, because the metal around the fuel rods, which is zirconium will burn once it reaches a certain ignition temperature. so there could be a zirconium fed fire that would only serve to increase heat up of the rods and accelerate radioactive release. this wouldn t typically result in an explosion of the fuel, but the reaction with zirconium does
this would cause fuel rods to expand, eventually to rupture, and first to release the gas that s already accumulated within spent fuel, and then as the uranium pellets in the fuel continue to heat up, more and more radioactive material will be squeezed out of the pellets, mostly in the form of cesium 137, which would be a gas at those temperatures. so if the fuel pool has gone dry, that would be a very hard condition to reverse. is there at that point a risk or either of those matter at that point? well, there would be presumably a fire, because the metal around the fuel rods, which is zirconium will burn once it reaches a certain ignition temperature. so there could be a zirconium fed fire that would only serve to increase heat up of the rods and accelerate radioactive
united states. so reactor facing similar crisis in the united states, evacuation zone would be default ten miles? that s right. in reactor four what the nrc said in testimony, all the water in number four reactor fuel pool is gone. if that s happened, if those fuel rods are in a dry pool, what happens to them? what happens there? i would like to caution, there s some dispute over whether that s true. but just assuming it is, if the spent fuel is completely dry, then heat transfer is significantly reduced and heatup of the fuel would accelerate. this would cause fuel rods to expand, eventually to rupture, and first to release the gas that s already accumulated within spent fuel, and then as the uranium pellets in the fuel continue to heat up, more and
thanks for being here. tell me what i got wrong in the explanation. the one thing i guess i would differ on is probably it wouldn t go all the way to meltdown in the pool, but it doesn t matter because long before that the volatile radioactivity would have been driven off by the heat. you don t need to go to meltdown to release the radioactivity we are concerned for the environment. just the damage to the fuel rods that could happen just by them being exposed to the air is enough to release radioactivity, that is the worst case. the planning around the uranium pellets, the tubes, would burst. at that point the heat would drive off the boiling point of the elements we are worried about is much below the temperature of the fuel we have at that point would drive it off into the atmosphere.