X-Message-Number: 20253 Date: Sat, 5 Oct 2002 14:54:35 -0700 Subject: Re: CryoNet #20208 Nuclear energy From: (Tim Freeman) > From: Thomas Donaldson > There seems to be a unified view that the pollution of nuclear > power will stay with us for a long time. That is, thousands of > years. At least 2 ways to deal with that problem in far less > than 1000 years can be suggested: > > 1. Throw the waste into the Sun. Probably would need nuclear rockets to get you there, so there may not be a net cleanup. > 2. Process it into useful elements > The problem that many get hung up on here is that such > processing can also produce material useful for weapons. I hear that this is not so. The Integral Fast Reactor project claims to do the reprocessing without having any intermiediate products that are nonradioactive enough to easily steal without killing off the thieves or pure enough to make into weapons. The reprocessed elements are used as recycled fuel, so it doesn't have to go anywhere. Check out: http://www.nuc.berkeley.edu/designs/ifr/ From: >The real problem is not here, it is in the Avogadro number: If the mass of a >typical radio-active atom is 60 atomic mass, then there are near 10 000 >billions of billions atoms in one g. Assume you are losing one part per >million of that material in the processing, that is 10 millions billions >atoms. If the half-life is 1000 year (31 billions seconds) There will be 150 >000 disintegrations per second in the environment. The important thing is how much damage the disintegrations do, not how many there are. Your 150,000 number is meaningless without this information. You have to look at the ratio between pollution produced and useful produced energy. Nuclear power has a high power density and highly toxic waste; the key question is how the ratio between these two high numbers compares to the corresponding ratio for, say, energy produced from coal. It's misleading to talk about the pollution without saying how much power was produced and how much pollution would result from producing that much power by other means. The outputs from the IFR are either stable or have a short (~30 year) half-life, so the 1000 year half-life is avoidable. The highly radioactive isotopes get sorted out and put back into the reactor until they transmute again. There's an article in there somewhere where the chief IFR guy admits that nuclear power is not economically necessary yet, since conventional means of producing power are presently somewhat cheaper. I'm more afraid of global warming than nuclear power, so I hope economics forces the shift soon. -- Tim Freeman GPG public key fingerprint ECDF 46F8 3B80 BB9E 575D 7180 76DF FE00 34B1 5C78 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=20253