Archived posting to the Leica Users Group, 2006/02/03
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Radon is definitely one of the sources to avoid. Radon is an alpha-emitter. Normally alpha isn't a big deal as long as you don't let it into your body - a piece of paper will stop it. But Radon is a gas and so the gas goes into your lungs where the radiation is applied directly to unprotected internal tissues - so caring about radon makes a lot of sense. Fortunately basements can be vented. Adam On 2/3/06, Douglas Sharp <douglas.sharp@gmx.de> wrote: > Most of Cornwall (UK) is built on granite bed-rock, many houses there > suffer from high concentrations of naturally occuring radioactive radon > gas seeping into cellars through the bedrock. > Douglas > > Raimo K wrote: > > > Thanks for the clarification of the picture - but I still see no > > radiation escape from the deep granite caves. > > All the best! > > Raimo K > > Personal photography homepage at: > > http://www.uusikaupunki.fi/~raikorho > > > > > > ----- Original Message ----- From: "Adam Bridge" <abridge@gmail.com> > > To: "Leica Users Group" <lug@leica-users.org> > > Sent: Thursday, February 02, 2006 7:55 PM > > Subject: Re: [Leica] RE: LUG Digest, Vol 31, Issue 221 > > > > > >> When Uranium is fissioned two different elements are created and each > >> of these elements is unstable (usually quite seriously unstable) and > >> so they decay into different nuclides by various mechanisms, all of > >> which give off serious amounts of gamma radiation. The half-lives of > >> these fission products vary but the entire chain takes tens of > >> thousands of years to reach low-level proportions. The spent fuel > >> isn't explosive although it does produce heat as a result of the > >> radioactive decay. They don't burn, in general they are metals > >> > >> The amount of radiation in a reactor core which has never been > >> critical, that is to say a self-sustaining nuclear reaction has never > >> happened in it, is quite small. Before the core was loaded into PARCHE > >> I was able to look up inside it with no protection except for the > >> requirement to keep everything VERY clean. > >> > >> But at the end of life the amount of radioactivity is quite vast - > >> many mega-Curies of radioactivity. (The Curie itself is a huge amount > >> of radioactivity, it represents a certain number of disintegrations > >> per second. Normal limits for things are normall expressed in > >> micro-micro-Curies to give you an idea.) > >> > >> As a rough approximation, if you are 1 meter away from a 1 Curie > >> source of gamma-emmiting you'll receive an exposure of 1 REM/hr. REM > >> is a measure of biological damage produced by radiation. > >> > >> The limit for non-radiation workers are .1 REM/year over and above > >> what you get from normal background radiation - ie cosmic rays etc. If > >> you live at altitude you get more than if you live at sea level for > >> example. Medical/Dental x-rays aren't counted in this either. You > >> typically get about 200 mili-rem from natural souces - radon gas which > >> happens naturally is the biggie - and 40 mili-REM from x-rays per > >> year. > >> > >> An exposure of (oh boy these numbers are hazy, it's been a long time) > >> of 50 REM over a short period will produce identifiable changes in > >> your blood. 100 Rem acute will make you ill, the threshold of > >> mortality is 150 REM and I think the 50/50 dose is 500 REM IF you get > >> the best medical treatment - meaning 50% of the people exposed will > >> die. 100% mortality is 800 REM. > >> > >> Radioactive waste from nuclear reactors is in the realm of mega-REM. > >> The decay of the fission products produces heat. Many of the elements > >> are themselves corrosive. So it's a tricky problem - especially if you > >> want to have something stored unguarded. Most fuel-rods are stored > >> deep under water in pools that are on the grounds of the reactor plant > >> that produced them. In fact, in the US this is where they have to STAY > >> since there is no long-term storage facility. > >> > >> As you might guess they are not easy to steal, either. Somehow you'd > >> have to take over a facility, find a big lead container, use remote > >> handling equipment, remove the rods, put them into the container, > >> move them. They are typically in stainless steel or zirconium cladding > >> of some sort or other. Trying to grab one without the remote handling > >> would be seriously ugly for the people attempting it. It ain't like > >> the movies. > >> > >> I hope this was useful and not too technical. My days as a reactor > >> operator are three decades past. I know that new units of measure are > >> now included in the SI system but I haven't had a reason to keep up. > >> > >> Adam Bridge > >> > >> On 2/2/06, Raimo K <raimo.m.korhonen@uusikaupunki.fi> wrote: > >> > >>> How can used stuff have more radiation than unused? If it had, it > >>> would be > >>> usable. > >>> OK, it is concentrated into granules but if you store it deep in > >>> stable rock > >>> caves (like we plan to do in Finland) and take into account the > >>> immense mass > >>> of stone around the storage I see no way it can have increased > >>> radiation > >>> compared with hot uranium mines. > >>> All the best! > >>> Raimo K > >>> Personal photography homepage at: > >>> http://www.uusikaupunki.fi/~raikorho > >>> > >>> > >>> ----- Original Message ----- > >>> From: "Douglas Sharp" <douglas.sharp@gmx.de> > >>> To: "Leica Users Group" <lug@leica-users.org> > >>> Sent: Thursday, February 02, 2006 12:51 AM > >>> Subject: Re: [Leica] RE: LUG Digest, Vol 31, Issue 221 > >>> > >>> > >>> > Hello Frank, > >>> > the refined stuff has a much higher radiation output than the ores > >>> - > think > >>> > of tiny granules of uranium mixed in with great chunks of rock > >>> which, > at > >>> > least partially stop the radiation, and, btw, make uranium mines > >>> so > hot. > >>> > There is one method of sealing nuclear waste which is effective as > >>> far > as > >>> > it goes, sealing it in glass with a large proportion of lead (which > >>> > doesn't shield from radiation, it absorbs it and changes over > >>> time) > this > >>> > has again the inherent problem of heat, the energy has to come out > >>> > somewhere. Before somebody suggests dropping it into volcanos, the > >>> > molten > >>> > lava is much too close to the surface, getting sprayed with molten > >>> rock > is > >>> > bad enough, but making it radioactive too is a bit much. > >>> > > >>> > As to the plastics, there are some fascinating developments on the > >>> way > >>> > with high quality plastics made from potato starches and waste > >>> straw > from > >>> > maize crops, then there's always multitudes of natural vegetable oils > >>> > which haven't really been tested for making the polymers we need for > >>> > plastics. > >>> > The power of biological products can be seen in the recipe for casein > >>> > glue - just mix curds and chalk - one of the best and oldest glues > >>> > there > >>> > is. > >>> > The energy business is going to become one of the main areas for the > >>> > development of genetically modified plant strains, the other area > >>> is > the > >>> > creation of bacteria which can reduce waste plastics to their > >>> original > >>> > source materials - but that is a pandora's box I don't care to think > >>> > about - just let a bacterium like that get out of hand or mutated > >>> and > >>> > start chewing up plastics just where it shouldn't, I shudder at the > >>> > thought. > >>> > It's interesting that most of the large oil companies are working > >>> very > >>> > hard in this direction, particularly Shell and BP, they want to > >>> have > the > >>> > market cornered when the time is ripe. There was a research > >>> project for > >>> > loosening up heavy oil deposits in a reservoir by dropping anaerobic > >>> > bacteria down through the borehole, but I left the business before > >>> > hearing > >>> > more about it. > >>> > The last stuff I was working on was the localisation of deep > >>> seated > magma > >>> > bodies for geothermal energy production in Tuscany (Larderello,where > >>> > they've been doing it since the early 1920s) my theory for > >>> variations > in > >>> > their heat production was that these bodies are also subject to tidal > >>> > forces caused by the position of the moon pulling them closer to the > >>> > surface, unfortunately I never did hear what came of that either. > >>> At > least > >>> > there was a significant increase in microseismicity (tiny earth > > >>> tremors) > >>> > at full moon, which seems to support my theory. > >>> > To get back on track, the visit to ENEL GreenPower in Pisa was a > > >>> wonderful > >>> > opportunity to wander around that beautiful city with a camera. > >>> > cheers > >>> > Douglas > >>> > > >>> > Frank Dernie wrote: > >>> > > >>> >> Douglas, > >>> >> I have always wanted to ask a specialist this question, and it looks > >>> >> like you may just be the person......... > >>> >> What is wrong with burying nuclear waste in the exhausted mines from > >>> >> which it originated? Presumably it won't be any more dangerous there > >>> >> than the raw nuclear material originally mined???? > >>> >> The biggest concern I have re oil is not its use as a fuel, that > >>> >> seems a > >>> >> terrible waste to me, but as the raw material for manufacturing > >>> >> materials such as plastics for which we have no reasonable >> > >>> alternative. > >>> >> Frank > >>> >> > >>> >> On 1 Feb, 2006, at 19:30, Douglas Sharp wrote: > >>> >> > >>> >>> The technologiy is clean enough, and close to being as safe as > >>> it >>> can > >>> >>> be - the problem is still nuclear waste. As a production and > >>> >>> exploration geophysicist I've worked on nuclear waste storage > >>> sites, > >>> >>> working and prospective, in Germany, Belgium, Switzerland and a > >>> few > >>> >>> other places. For the long-term storage of nuclear waste there > >>> is NO > >>> >>> really safe solution, that stuff stays highly radioactive on a > >>> >>> geological time scale. > >>> >>> Salt dome caverns are no good - salt moves and migrates so you've > >>> >>> never got a constant thickness shielding your waste, the Swiss > >>> >>> solution > >>> >>> of putting it in caverns blasted out of native impervious >>> > >>> (supposedly) > >>> >>> rocks is better but radiactive gases (Radon for example) always > >>> >>> manage > >>> >>> to find a way to the surface. The Belgian method of hiding it > >>> under >>> a > >>> >>> thin layer of impervious clay isn't a long term solution either. > >>> >>> So what do we do with it? Shooting it into the sun is the only > >>> real > >>> >>> way of getting rid of it, there's been enough dropped into the > >>> sea >>> and > >>> >>> more than enough buried already, these "fly-dumps" will take their > >>> >>> revenge on the environment one of theses days. > >>> >>> You say that present day technologies are safe, I agree - > >>> problem >>> is, > >>> >>> even the most recent reactors just haven't been built with > >>> these new > >>> >>> technologies, Temsvar in the Czech Republic is one of the > >>> newest >>> NPSs > >>> >>> and is just not safe, the same applies to the latest French >>> > >>> reactors, > >>> >>> Germany's reactors have been plagued with problems and > >>> Sellafield in > >>> >>> the UK is a dirty word already. No need to mention reactors in the > >>> >>> former soviet block countries....... > >>> >>> > >>> >>> Fusion power is pie-in-the-sky (unless the billions for defence are > >>> >>> re-channeled), you might just as well try a further development of > >>> >>> Nikolaus Tesla's idea by building orbiting spaceborne solar power > >>> >>> stations transmitting power as high energy microwave frequencies > >>> >>> back > >>> >>> to earth, though I dread to think what would happen if a plane > >>> flew > >>> >>> through one of those tight banded transmissions. > >>> >>> The only clean options are terrestrial solar energy farms, > >>> wind and > >>> >>> tidal energy and geothermal energy - these are the only future > >>> I can > >>> >>> see in power production. > >>> >>> > >>> >>> Some of the latest developments reek of science fiction but > >>> could be > >>> >>> effective - half mile high chimneys set up in desert regions, the > >>> >>> temperature differential between ground level and the top > >>> creates >>> winds > >>> >>> of incredible velocities, all you have to do is put aturbine in > >>> the >>> way > >>> >>> of it. Using waste energy (off peak production is always too > >>> high >>> and > >>> >>> just gets wasted) from conventional power stations to pump > >>> water >>> into > >>> >>> high level reservoirs > >>> >>> to run hydroelectric turbines at peak demand times, storing > >>> energy >>> as > >>> >>> compressed air in salt domes is another option, use it to > >>> supply the > >>> >>> energy needed to get gas turbines running. > >>> >>> > >>> >>> None of these, however give us any kind of solution for automotive > >>> >>> transport - when the oil runs out we're going to back with sailing > >>> >>> ships and steam engines again, individual or personal > >>> transportation > >>> >>> will be the rich man's game. > >>> >> > >>> >> > >>> >> > >>> >> _______________________________________________ > >>> >> Leica Users Group. > >>> >> See http://leica-users.org/mailman/listinfo/lug for more information > >>> >> > >>> >> > >>> > > >>> > _______________________________________________ > >>> > Leica Users Group. > >>> > See http://leica-users.org/mailman/listinfo/lug for more information > >>> > >>> > >>> _______________________________________________ > >>> Leica Users Group. > >>> See http://leica-users.org/mailman/listinfo/lug for more information > >>> > >> > >> > >> _______________________________________________ > >> Leica Users Group. > >> See http://leica-users.org/mailman/listinfo/lug for more information > > > > > > > > _______________________________________________ > > Leica Users Group. > > See http://leica-users.org/mailman/listinfo/lug for more information > > > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >