timothym@tekigm2.UUCP (Timothy D Margeson) (08/06/86)
There has been some discussion about nuclear waste and the side effects: One of the pro arguments states that we can safely dispose of the effluent and keep the site safe over the many hundreds to thousands of years, thus preventing our grandchildren from accidentally digging into the waste dump. I put to you the fact there are documented cases of arsenic disposal sites created in the 1930's used for drinking water wells in the 1980's. A mere 50 years and we lost the dangers lurking beneath the ground. The excuse or argument that we have better communication now than in 1950 holds no ground because a small war can destroy any and all of this better communication in minutes. And the war need not be nuclear itself to do so. Disposing of dangerous materials, whether nuclear waste, chemical waste, or whatever you can think of being toxic to our grandchildren or their children in dumps is unsafe, period. The material sunk into the ground, even in salt domes will eventually be dug up, drilled through or somehow exposed, causing at least minor injuries before the cause is isolated. I don't have the answers, nor do I have the right questions to ask, but I do intuitively know that creating large amounts of 'stuff' that we don't know what we are going to do with after we make it, scares me. Think about where you live. Someone has been there before you. What did they do on your lot, maybe they mixed rat poison, maybe they mixed bread. Unless you took the time to find out, you may unwittingly dig a vegy garden (or a pool by the vegies) in dirt once used as a cattle or sheep insecticide dip tank, and now you plant your tomatoes in it. I for one would not like to think that what I did might kill someone at some point in time after I have left this Earth. I do enough damage while I live. Thought to think about. Toodles....
mvs@meccts.UUCP (Michael V. Stein) (08/08/86)
In article <859@tekigm2.UUCP> timothym@tekigm2.UUCP (Timothy D Margeson) writes: >There has been some discussion about nuclear waste and the side effects: >...I put to you the fact there are documented cases of arsenic disposal sites >created in the 1930's used for drinking water wells in the 1980's. A mere >50 years and we lost the dangers lurking beneath the ground. >...I don't have the answers, nor do I have the right questions to ask, but I do >intuitively know that creating large amounts of 'stuff' that we don't know >what we are going to do with after we make it, scares me. You bring up the major problems with waste disposal, whether it be chemical, biological or nuclear. But, lets look a little more closely at nuclear waste disposal. The annual high level wastes from a 1000 MW nuclear power plant would occupy approximately 90 cubic feet. (A cube 4.5 feet on each side.) This cube would contain around 20 million curies of radioactivity making it an obvious health hazard. The radiation intensity will decrease by a factor of 10 after a hundred years, and by a factor of 10,000 after four hundred years. After 6 hundred years, the only hazard is if it is ingested. Therefore the "hundreds or thousands of years" reference is a bit overstated. The long term safety of geologic disposal depends on ensuring that the wastes aren't released into the outside environment. There are three ways that a waste release could occur: Exhumation from the repository by some natural event; Exhumation as a result of human intrusion; Slow transport of waste materials via ground water into water supplys. To prevent radionuclides from getting into the groundwater, all disposal plans call for the wastes to be stored in glass or ceramics so it not neither chemically active or water soluble. Then the repository is located away from all ground water. (This is why you often hear about the use of salt mines.) The most commonly mentioned type of human intrusion is drilling and intercepting a canister. This is why the disposal site would be located in an area unlikely to have the natural resources that would attract such drilling. So, for human exposure to occur, the following unlikely chain of events would have to occur. First, the presence of the repository would have to be forgotten. Secondly, there would have to be some reason to choose the repository as an exploration site. Thirdly, the radioactivity of the material would have to go unnoticed during drilling. Fourth, for noticeable health effects, the drilling would have to hit a canister nearly head on. Fifth, the radioactive material would have to be brought to the surface and left exposed. If any of these did not occur, significant release of radiation would not occur. While all of the above is theoretically possible, it is much less risky then almost any other hazardous material that we dispose of in the environment. Geologic disposal has emerged as the preferred waste disposal system in each of the major nuclear countries. The West German program emphasizes disposal in salt, as does the Netherlands. Sweden, the United Kingdom, France and Canada are concentrating on crystalline rocks, such as granite and basalt. Italy and Belgium are investigating clays, mudstone and shales. -- Michael V. Stein Minnesota Educational Computing Corporation - Technical Services UUCP ihnp4!dicome!meccts!mvs
ken@argus.UUCP (Kenneth Ng) (08/09/86)
In article <859@tekigm2.UUCP>, timothym@tekigm2.UUCP (Timothy D Margeson) writes: > There has been some discussion about nuclear waste and the side effects: > > One of the pro arguments states that we can safely dispose of the effluent > and keep the site safe over the many hundreds to thousands of years, thus > preventing our grandchildren from accidentally digging into the waste dump. Here we go again, anyone here remember the discussion in net.politics? I do not have the time to debate that arguement again here, but I wish to provide some reading material for those interested. First, we don't need to keep radioactive waste isolated for thousands, or millions of years. In 300 years the total radiological hazard is less than the ore it came from. In other words, after 300 years, we will be on a net basis cleaning up the world. For those interested, please read "High-Level Radioactive Waste from Light Water Reactors", by Bernard L. Cohen, Reviews of Modern Physics, January 1977, pages 1 to 20. Appendix C shows calculations which indicate that the time to dissolve the salt bed in which nuclear waste is enclosed to be 60,000 years, which is 200 times the time we need. And this assumes that we missed finding a water source in the salt bed. But even after this the water has to corrode through the cannisters and dissolve the waste, which is glassous, and not easy to dissolve, although it will. I think someone will start wondering what they are on top of if they start bring up chunks of stainless steel, quartz, and benezanne (sp) clay, which is used in the container design. If you really want a proven design structure that will withstand the ravages of time, let's build the pyramids over again. We know that they can withstand 300 years easily, I think they date back a couple thousand years. The only future risk will be to those who go inside before 300 years. I think that people will figure out something is wrong when everyone who goes in dies of radiation poisoning. I will probably not be adding much more to this discussion because my productivity dropped greatly during the debate in net.politics. But I'll be glad to answer individual inquires (provided I don't get too many of them) via E-mail. -- Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102 uucp(for a while) ihnp4!allegra!bellcore!argus!ken !psuvax1!cmcl2!ciap!andromeda!argus!ken *** WARNING: NOT ken@bellcore.uucp *** bitnet(prefered) ken@njitcccc.bitnet or ken@orion.bitnet Spock: "Captain, you are an excellent Starship Captain, but as a taxi driver, you leave much to be desired." Kirk: "What do you mean, 'if both survive' ?" T'Pow: "This combat is to the death"
ken@argus.UUCP (Kenneth Ng) (08/09/86)
In article <479@meccts.UUCP>, mvs@meccts.UUCP (Michael V. Stein) writes: > > To prevent radionuclides from getting into the groundwater, all > disposal plans call for the wastes to be stored in glass or ceramics > so it not neither chemically active or water soluble. Then the > repository is located away from all ground water. (This is why you > often hear about the use of salt mines.) Almost but not quite right. In order to lower the odds of the site becoming a future salt mine, you want a salt bed that does NOT have a plentiful source of fresh water available. Salt mines are usually found where there is both a salt bed and a large source of fresh water (to mine the salt of course). > Geologic disposal has emerged as the preferred waste disposal system > in each of the major nuclear countries. The West German program > emphasizes disposal in salt, as does the Netherlands. Sweden, the > United Kingdom, France and Canada are concentrating on crystalline > rocks, such as granite and basalt. Italy and Belgium are > investigating clays, mudstone and shales. Check out Sweden, they have a VERY expensive radioactive waste container. But it is probably the most indestructable of all the container schemes. > Michael V. Stein > Minnesota Educational Computing Corporation - Technical Services > > UUCP ihnp4!dicome!meccts!mvs Not you again! (:-> -- Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102 uucp(for a while) ihnp4!allegra!bellcore!argus!ken !psuvax1!cmcl2!ciap!andromeda!argus!ken *** WARNING: NOT ken@bellcore.uucp *** bitnet(prefered) ken@njitcccc.bitnet or ken@orion.bitnet Spock: "Captain, you are an excellent Starship Captain, but as a taxi driver, you leave much to be desired." Kirk: "What do you mean, 'if both survive' ?" T'Pow: "This combat is to the death"