Heavy Metal
From the Wall Street Journal, 25 March 2011
So far, the U.S. has generated roughly 70,000 metric tons of nuclear waste—enough to fill a football field more than 15 feet deep, according to the Government Accountability Office. The GAO has projected that number will more than double to 153,000 metric tons by 2055.
You didn't think I would let this go without fact-checking, did you?
A football field is 360 feet by 160 feet, or 57,600 square feet. A block of nuclear waste 15 feet high occupying these dimensions would be 864,000 cubic feet. That means that nuclear waste should weigh 70,000/864,000 or .08 metric tons per cubic foot. A metric ton is 1,000 kilograms, or about 2,200 pounds, so .08 metric tons is 176 pounds. A long remembered fact is that water is about 62.5 pounds per cubic foot, which would make the average chunk of nuclear waste 2.8 times as dense as water. Although uranium itself is 19 times as dense as water and the zirconium fuel rod cladding is 6.5 times as dense as water, I can't say (without research, of course) that the 2.8 figure isn't a believable factoid. Who knows what's mixed in with that waste? Fact checking complete, lead helmet off to the GAO for a reasonable estimate and the Journal for not messing up their quote.
Sort of makes you wonder, though, why in the entire United States with all its football fields, we can't find anywhere to put our nuclear waste.
Missing Elements
I was going to say a few words about other heavy metals here. Uranium just makes it into the top ten - Lead isn't even close! The heaviest is osmium, followed by iridium and then platinum. Gold, everyone's favorite is slightly denser than uranium, and tungsten, one of my personal favorites for reasons that I hope to disclose some day, is right above gold. But I was shocked to discover that the links* in my own periodic table, previously incomplete only in the lack of certain element mentions in the Journal, have gone missing in their entirety. Perhaps Los Alamos National Lab is cranky that I photographed their badges, and has denied me access to their data.
The links moved and have been fixed. I guess LANL doesn't do cranky very well. Thanks, Bill, for finding them.
