Sweden -- how it deals with radioactive waste

did you know that approximately half of all electricity used in Sweden comes from nuclear power such as Oskar some nuclear power plants behind me as you probably know the nuclear waste is radioactive and dangerous if it's not handled correctly this has caused different opinions on nuclear power many think it's good while others believed it to be bad the problem is that regardless of how you feel about nuclear waste we've used nuclear power in Sweden for over 35 years and that means that we already have a large amount of ways to take care of at skv where I work we don't take a stance on nuclear power instead we have the job of developing a system to take care of the radioactive waste how we deal with that problem that's what this film is all about this is what nuclear reactor fuel looks like it's uranium dioxide in a ceramic form the small cylinders are called pellets and before they've been used as fuel they give off so little radiation that you can hold them in your hand inside the reactor millions of pellets are gathered into long metal pipes when water flows between them the fission process begins which generates heat that is used to produce electricity but at the same time many new substances are formed in the fuel and some of these are highly radioactive and poisonous every year about one-fifth of the fuel and the nuclear reactor is replaced first the fission process is stopped with the aid of control rods the effect of the fuel assembly immediately drops from 30 million watts to 2 million watts per tonne of fuel and within a few days the effect has dropped to 200 thousand watts the fuel assembly is then placed in a pool inside the nuclear power plant and stored for about a year during this year most of the radioactive substances dissipate the radiation and heat effect Falls to 20,000 watts and that is a 90% drop but even so there's still a long way to go before the fuel is harmless if we compare the radiation and heating effect of fuel removed from the reactor to a 22 storey building it would look something like this after one year the effect is reduced to 1/10 which is equivalent to a house after 30 years the effect will have dropped another 90 percent about the size of a dog house and after 1,000 years it will be as tall as a snail's house but the fuel will still be dangerous for a long time to come after the spent fuel has lain in the pool inside the reactor building for about a year it's easier to handle however the radiation and heat are still so high that the waste has to be shielded and cooled therefore it's moved to durable casks that securely protect against radiation before it's transported to club Club is the central interim storage facility for spent nuclear fuel all Sweden spent nuclear fuel is brought here before we're going to find a long-term storage site but how is it brought here all nuclear power plants in Sweden are on the coast so the best way to transport nuclear fuel from the power plants to club is by sea but not just by any boat it's done by MSC ghen MSC in is custom designed to transport nuclear waste she's built with a double hull which provides a four meter buffer to absorb the first impact in the event of a collision it also makes the MSC and extremely buoyant compared to other ships we are the normal stress value advantaging hot boiled not our storm so you're innocent regarding a system at little pokey an orthodontist a at the scale of rama missed it man notice a at siegen endoskeletal bottom so adding and direct risk for all Manhattan for the island Seon is a some are credit most ruining certain they are the whole lana was a noticeable Oloroso valedale fast sir oddity forty yet nearly lost to miss Finster fired again fastening arideca Stella never hold on of all peoples the first on gold etc when the MS Siegen arrives at the harbor at Club the transportation casks are unloaded and driven to collapse receiving area on arrival to clap the fuel is very hot and must therefore be cooled before the transport casks are opened this is done by pumping water through them after that the casks are taken to a pool and docked from below with a pool above following that the fuel element is transferred to a storage cassette this ingenious construction prevents the outside of the transport casks from ever coming in contact with radioactive substances next the storage cassette with a waste is sent down to the storage pools the water in the pools circulates in a closed system that transfers the heat to the ocean through a heat exchanger in this way the hot fuel is continuously cooled the fuel is always covered by three to eight meters of water the water cools the fuel and it's also shields from the radiation so they can stand this close to the fuel without being exposed to radiation from it moreover this facility lies 25 meters underground and can withstand an airplane crash as well as an earthquake of course they're also backup systems for both water cooling and electricity should anything happen the fact is that even if all of the backup systems failed it wouldn't cause a catastrophe the volume of water in the storage pools is so great that it would take a month for enough to evaporate and expose the fuel and if for some reason the electricity couldn't be turned back on then water could temporarily be added the fuel has to be stored for at least 30 years in club so that the heat release diminishes thereafter it can be stored without high temperatures occurring theoretically the waste could be stored in clubs ponds for hundreds of years but then we'd be putting the burden of surveillance and ensuring the pumps and fans work on to future generations so we've been forced to find a solution that is permanent and that does not put any demands on to future generations the solution is the final repository a deep repository doesn't yet exist but this is how it will work the main part of the repository will lie 500 meters down in the Swedish bedrock it's a very stable environment where any possible changes occur very slowly over time down there canisters with waste will be individually placed in pre-board holes in a tunnel system as just one meter of rock is sufficient to stop the radiation emitted from the waste damage on animals and humans can only occur if radioactive particles are transported back up to the surface therefore we've developed a method in which different barriers will prevent any possible radioactive leakage for over 100,000 years first of all the fuel the tiny pellets is as hard to dissolve in water as the rock itself mater is mainly releasable from the surface of the pellet to isolate the fuel it's stored in cast-iron containers inside thick copper canisters copper is a noble metal that in the oxygen-free environment deep in the bedrock won't corrode that means to rest where the copper canisters are placed in the rock they'll be surrounded by bentonite clay a kind of swelling clay that becomes very dense and prevents water from flowing around the canisters finally the mountain itself is a barrier if both the copper canister and the bentonite clay fails then the mountain itself can retain or hinder most of the radioactive substances along with the final repository an encapsulation plant will be needed there the fuel will be put into the copper canisters which are then welded shut and checked before transportation deep down into the repository for final storage right now work is underway to find a safe place for the final repository this investigation is expected to be completed in 2009 and will give the authorities and the government a basis for making a decision on the final repository if all goes as planned the first fuel canisters will be placed in the repository in 2018 by then we will have a complete system in operation for handling all radioactive waste beside the used fuel nuclear power also creates other kinds of waste that has to be taken care of for example things that have become radioactive during operation of the nuclear power plant filters replaced reactor parts protective gloves or overalls that have been contaminated during maintenance work this kind of waste is divided into low and intermediate level waste and it has its own file repository at SFR that's a facility near the Forsch mark nuclear power plant in upland that lies about one kilometer off the coast and 50 meters beneath the ocean floor here the waste will be isolated from people animals and nature during the 500 years that it's dangerous but before transportation the waste needs to be packed some of the low-level waste containing clothes and tools among other things is burnt so it takes up less space the ashes are then put into steel plate containers also some non combustible waste such as scrap iron is melted down so it takes up as little room as possible during final storage the intermediate level wastes mainly consisting of filters is mixed with asphalt or cement and cast in protective steel or cement containers it can then be transported with MSE into SFR the special thick walled steel containers effectively contain the radiation and protect against mechanical damage simply put you could say that SFR consists of four large rock vaults and a deep silo low-level waste can be handled directly with forklift trucks intermediate level waste on the other hand is either handled by a remote-controlled overhead crane and large concrete compartments or in the large disposal shaft that's embedded in protective bentonite once the different compartments are filled they're cast in cement and finally added so far some low and intermediate level waste from hospitals research and industries are also taken care of the same principle is true for so far as to the future final repository different barriers will hinder the groundwater from transporting radioactive material back to the surface as felt in concrete that encapsulates the waste bentonite clay around the silo that swells and seals in contact with water and finally the surrounding rock in total SKB will take care of enough waste to fill one third of the Stockholm Globe Arena approximately 10% of it is high-level waste from spent nuclear fuel 25% is low an intermediate level operational waste another 55 percent will be decommissioning waste from torn down nuclear power plants and the remaining 10% will be other long-lived waste from when the power plants club and the encapsulation plant are torn down how this long-lived waste is to be stored will be decided at a later point in time for us at skb it's all about developing a good method and finding a safe place for storage of the waste this has been our challenge for more than 25 years now and it can be said that we lead the way in research in this area experts from all over the world come here to learn more about the Swedish system in the long run this is all a question about responsibility it's not reasonable to expect future generations to take care of our waste products we use the electricity that the nuclear power plants produce and so we have the obligation to take care of the waste products as well

Channel: Nuclear Decommissioning Authority

Views: 101,696

Keywords: NDA, Radioactive Waste (Film Subject), Sweden, Nuclear, geological disposal, decommissioning

Id: asP-3Z8-q4o

Length: 14min 28sec (868 seconds)

Published: Tue Sep 24 2013