James, I was NOT trying to be silly with my comparison of spent vs new fuel rods. I agree that nuclear energy should be used (perhaps with different reactors= than most used in the US presently).The traveling wave reactor sounds nice= =20 http://earth2tech.com/2010/02/15/terrapower-how-the-travelling-wave-nuclear= -reactor-works/ Sorry about the under house concept. I was trying to point out that spent f= uel is ENORMOUSLY hotter than the stuff out of the ground, and remains so f= or many years. Yes, in the long run the net radioactivity may be reduced ca= use we "used it up" in the reactor.=20 The under house thing came from the fact that some developers in Colorado w= ere using uranium mine tailings for landfill.=20 http://www.iacenter.org/depleted/kaku.htm But then, some people misbehave. As far as dilution goes, ask the folks downwind of Chernoble about that. I would rather keep the waste concentrated and bury it (or better, burn it = in the traveling wave reactor). Be aware that some of the waste products ar= e bio - acumulative like iodine and cesium for instance. http://www.wtop.com/?nid=3D383&sid=3D2030931 Looking forward, Al Shinn --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .