No country is currently planning to implement long-term i. However, France is investigating long-term interim storage, but not necessarily above ground. EKRA observed that it was unclear what additional steps would be necessary to show how the long-term above ground storage concept could be brought to the state of development comparable with that of geological disposal, and it recommended geological disposal as the preferred option. The objective of this option is to remove the radioactive waste from the Earth, for all time, by ejecting it into outer space.
The waste would be packaged so that it would be likely to remain intact under most conceivable accident scenarios. A rocket or space shuttle would be used to launch the packaged waste into space. There are several ultimate destinations for the waste which have been considered, including directing it into the Sun.
The high cost means that such a method of waste disposal could only be appropriate for separated HLW — i. Because of the high cost of this option and the safety aspects associated with the risk of launch failure, it was abandoned. The deep rock melting option involves the melting of wastes in the adjacent rock. The idea is to produce a stable, solid mass that incorporates the waste, or encases the waste in a diluted form i.
This technique has been mainly suggested for heat-generating wastes such as vitrified HLW see information paper on Treatment and Conditioning of Nuclear Wastes and host rocks with suitable characteristics to reduce heat loss.
The HLW in liquid or solid form could be placed in an excavated cavity or a deep borehole. The heat generated by the wastes would then accumulate resulting in temperatures great enough to melt the surrounding rock and dissolve the radionuclides in a growing sphere of molten material.
As the rock cools it would crystallize and incorporate the radionuclides in the rock matrix, thus dispersing the waste throughout a larger volume of rock. There are some variations of this option in which the heat-generating waste would be placed in containers and the rock around the container melted. Alternatively, if insufficient heat is generated the waste would be immobilized in the rock matrix by conventional or nuclear explosion.
Rock melting has not been implemented anywhere for radioactive waste. There have been no practical demonstrations of the feasibility of this option, apart from laboratory studies of rock melting. In the late s and early s, the rock melting option at depth was taken forward to the engineering design stage. This design involved a shaft or borehole which led to an excavated cavity at a depth of 2. It was estimated, but not demonstrated, that the waste would be immobilized in a volume of rock times larger than the original volume of waste.
Another early proposal was for the heat-generating wastes to be emplaced in weighted, heat-resistant containers such that they would melt the underlying rock, allowing them to move downwards to greater depths with the molten rock solidifying above. This proposed option resembles similar self-burial methods proposed for disposal of HLW in ice sheets see section below on Disposal in ice sheets. In the s there was renewed interest in this option, particularly for the disposal of limited volumes of specialized HLW particularly plutonium in Russia and in the UK.
A scheme was proposed in which the waste content of the container, the container composition, and the placement layout would be designed to preserve the container and prevent the wastes becoming incorporated in the molten rock.
The host rock would be only partially melted and the container would not move to greater depths. Russian scientists have proposed that HLW, particularly excess plutonium, could be placed in a deep shaft and immobilized by nuclear explosion. However, the major disturbance to the rock mass and groundwater by the use of nuclear explosions, as well as arms control considerations, has led to the general rejection of this option.
Subduction zones are areas where one denser section of the Earth's crust is descending beneath another lighter, more buoyant section. The movement of one section of the Earth's crust below another is marked offshore by a trench, and earthquakes commonly occur adjacent to the inclined contact between the two plates. The edge of the overriding plate is crumpled and uplifted to form a mountain chain parallel to the trench. Deep sea sediments may be scraped off the descending slab and incorporated into the adjacent mountains.
As the oceanic plate descends into the hot mantle, parts of it may begin to melt. The magma thus formed migrates upwards, some of it reaching the surface as lava erupting from volcanic vents. The idea for this option would be to dispose of wastes in the trench region such that they would be drawn deep into the Earth. Although subduction zones are present at a number of locations across the Earth's surface, they are geographically very restricted.
Not every waste-producing country would be able to consider disposal to deep-sea trenches, unless international solutions were sought. However, this option has not been implemented anywhere and, as it is a form of sea disposal, it is therefore not permitted by international agreements. Disposal at sea involves radioactive waste being dropped into the sea in packaging designed to either: implode at depth, resulting in direct release and dispersion of radioactive material into the sea; or sink to the seabed intact.
Over time the physical containment of containers would fail, and remaining radionuclides would be dispersed and diluted in the sea. Further dilution would occur as the radionuclides migrated from the disposal site, carried by currents. The amount of radionuclides remaining in the seawater would be further reduced both by natural radioactive decay, and by the removal of radionuclides to seabed sediments by the process of sorption.
The application of the sea disposal of LLW and ILW has evolved over time from being a disposal method that was actually implemented by a number of countries, to one that is now banned by international agreements.
This option has not been implemented for HLW. For the sub-seabed disposal option, radioactive waste containers would be buried in a suitable geological setting beneath the deep ocean floor.
Variations of this option include:. Sub-seabed disposal has not been implemented anywhere and is not permitted by international agreements. The disposal of radioactive wastes in a repository constructed below the seabed has been considered by Sweden and the UK.
In comparison to disposal in deep ocean sediments, if it were desirable the repository design concept could be developed so as to ensure that future retrieval of the waste remained possible. The monitoring of wastes in such a repository would also be less problematic than for other forms of sea disposal. Burial of radioactive waste in deep ocean sediments could be achieved by two different techniques: penetrators or drilling placement.
The burial depth of waste containers below the seabed can vary between the two methods. In the case of penetrators, waste containers could be placed about 50 metres into the sediments. Penetrators weighing a few tonnes would fall through the water, gaining enough momentum to embed themselves into the sediments.
A key aspect of the disposal of waste to seabed sediments is that the waste is isolated from the seabed by a thickness of sediments. In , some confidence in this process was obtained from experiments undertaken at a water depth of approximately metres in the Mediterranean Sea.
The experiments provided evidence that the entry paths created by penetrators were closed and filled with remoulded sediments of about the same density as the surrounding undisturbed sediments. Wastes could also be placed using drilling equipment based on the techniques in use in the deep sea for about 30 years. By this method, stacks of packaged waste would be placed in holes drilled to a depth of metres below the seabed, with the uppermost container about metres below the seabed.
For this concept, radioactive waste would be packaged in corrosion-resistant containers or glass, which would be placed beneath at least metres of water in a stable, deep seabed geology chosen both for its slow water flow and for its ability to retard the movement of radionuclides. Radionuclides that are transported through the geological media, to emerge at the bottom of the seawater volume, would then be subjected to the same processes of dilution, dispersion, diffusion, and sorption that affect radioactive waste disposed of at sea see section above on Sea Disposal.
This method of disposal therefore provides additional containment of radionuclides when compared with the disposal of wastes directly to the seabed. Containers of heat-generating waste would be placed in stable ice sheets such as those found in Greenland and Antarctica. The containers would melt the surrounding ice and be drawn deep into the ice sheet, where the ice would refreeze above the wastes creating a thick barrier.
Although disposal in ice sheets could be technically considered for all types of radioactive wastes, it has only been seriously investigated for HLW, where the heat generated by the wastes could be used to achieve self-burial within the ice by melting.
The option of disposal in ice sheets has not been implemented anywhere. It has been rejected by countries that have signed the Antarctic Treaty or have committed to providing a solution to their radioactive waste management within their national boundaries. This approach involves the injection of liquid radioactive waste directly into a layer of rock deep underground that has been chosen because of its suitable characteristics to trap the waste i.
In order to achieve this there are two geological prerequisites. There must be a layer of rock injection layer with sufficient porosity to accommodate the waste and with sufficient permeability to allow easy injection i.
Above and below the injection layer there must be impermeable layers that act as a natural seal. Additional benefits could be provided from geological features that limit horizontal or vertical migration. For example, injection into layers of rock containing natural brine groundwater. This is because the high density of brine salt water would reduce the potential for upward movement. Direct injection could in principle be used on any type of radioactive waste provided that it could be transformed into a solution or slurry very fine particles in water.
Slurries containing a cement grout that would set as a solid when underground could also be used to help minimize movement of radioactive waste. In extensive geological investigations started in Russia for suitable injection layers for radioactive waste. Three sites were found, all in sedimentary rocks. At Krasnoyarsk and Tomsk-7 injection takes place into two porous sandstone beds capped by clays at depths up to metres.
Whereas at Dimitrovgrad injection has now stopped, but took place into sandstone and limestone formations at a depth of metres. In the USA, direct injection of about cubic metres of LLW as cement slurries was undertaken during the s at a depth of about metres over a period of 10 years at the Oak Ridge National Laboratory, Tennessee. It was abandoned because of uncertainties over the migration of the grout in the surrounding fractured rocks shales. In addition a scheme involving HLW injection into crystalline bedrock beneath the Savannah River Site in South Carolina was abandoned before it was implemented due to public concerns.
Radioactive material is produced or collected as a waste product from the oil and gas industry and generally referred to as 'technologically enhanced naturally occurring radioactive material' Tenorm m. In oil and gas production, radium, radium and lead are deposited as scale in pipes and equipment in many parts of the world.
The largest Tenorm waste stream is coal ash, with million tonnes arising globally each year, and carrying uranium and all its non-gaseous decay products, as well as thorium and its progeny.
This is usually just buried. In the USA, the Yucca Mountain site in Nevada has been chosen to site a deep geologic repository for disposal of high-level radioactive waste, but the project is beset by political interference. However, soon after entering office, the Barack Obama administration decided to cancel the project. Information on the Finnish repositories for operating waste can be found on Posiva's website.
The Swedish repository programme is described in various SKB publications. The Swiss National Cooperative for the Disposal of Radioactive Waste Nagra has proposed three siting regions for the high-level waste repository. See the Nagra website www.
The website of the Waste Isolation Pilot Plant is at www. In the UK, much of these wastes are exempt from the need for their disposal to be authorized under the UK's Radioactive Substances Act because of their low levels of radioactivity.
However, some of the wastes are of higher activity and there are currently a limited number of disposal routes available. This includes re-injection back into the borehole i. The main radionuclide in scrap from the oil and gas industry is radium, with a half-life of years as it decays to radon. Malcolm B. Storage and Disposal of Radioactive Waste Updated May Radioactive wastes are stored so as to avoid any chance of radiation exposure to people, or any pollution.
The radioactivity of the wastes decays with time, providing a strong incentive to store high-level waste for about 50 years before disposal. Disposal of low-level waste is straightforward and can be undertaken safely almost anywhere. Storage of used fuel is normally under water for at least five years and then often in dry storage. Deep geological disposal is widely agreed to be the best solution for final disposal of the most radioactive waste produced.
Deep geological disposal at depths between m and m for mined repositories, or m to m for boreholes Long-lived ILW and HLW including used fuel Most countries have investigated deep geological disposal and it is official policy in several countries. Facility under construction and due to begin operations in in Finland. Geological repository site selection process commenced in the UK and Canada.
Near-surface disposal The International Atomic Energy Agency IAEA definition b of this option is the disposal of waste, with or without engineered barriers, in: Near-surface disposal facilities at ground level. These facilities are on or below the surface where the protective covering is of the order of a few metres thick.
Waste containers are placed in constructed vaults and when full the vaults are backfilled. Eventually they will be covered and capped with an impermeable membrane and topsoil. Say what? Commercial used nuclear fuel is a solid Used fuel refers to the uranium fuel that has been used in a commercial reactor.
The U. Used fuel is stored at more than 70 sites in 34 U. Used fuel is safely transported across the United States Over the last 55 years, more than 2, cask shipments of used fuel have been transported across the United States without any radiological releases to the environment or harm to the public.
Used nuclear fuel can be recycled to make new fuel and byproducts. Nuclear Energy Basics. Phil March 30, AM. Partially spent nuclear fuel will be used as a fuel source for Generation 4 reactors being developed now by Bill Gates' TerraPower and others. It will supply electricity for decades without mining any more uranium. Dry Cask storage is safe and adequate for the near future. In my opinion and that of many others permanent disposal is costly and not necessary. Tony April 19, PM.
Yes, TerraPower is by far the best way to use spent nuclear materials, e. Or we could have engineers manage the effort and actually get something accomplished. The solution does not have to be perfect, it only has to be good enough for a couple of hundred years.
At that point the radiation levels are reasonably low. Worrying about the disposition of plutonium in the distant future is a classroom exercise. TptDac April 1, AM. I have given thought to the issue of what kind of people could run a successful nuclear waste disposal project.
I spent a fair part of my career as a scientist working on such projects. When the scientists were in charge, the funding tended to be a feeding trough for people who did what they wanted to do anyway. When the engineers were in charge, things were more focused on the end result. There was always some component of basic science that was actually needed to attain the end result.
I am not impressed with this article. It presents a happy picture Wow, now we know what to do! Look up the history of project failures, going back about four decades or so e. The article should have included something about the long history of failures, especially those related to vitrification. Bart Ziegler May 19, AM. Excellent comment. Tom March 30, PM. This industry has never known what to do with the waste. They are idiots for ever making any of it. Nature out of place.
Don't blame the industry. The federal government promised to figure out the waste disposal issue. These researchers complain about kicking the waste "problem" down the road. The truth is that their own remarks, and articles like this, make it more likely that it will continue to be kicked down the road.
The nuclear waste "problem" is purely political. It has been technically solved for a long time. The fact is that any risks long-term as well as shorter term associated with nuclear waste are tiny compared to those associated with other industries' and energy sources' pollution and waste streams. Even with all the supposedly significant issues these researches go on about, the long-term risks of other waste streams are orders of magnitude larger.
It is the only industry that is containing all its wastes and is ensuring that they remain contained for as long as they remain hazardous. NRC has concluded that Yucca Mountain would meet that impeccable, unprecedented requirement that no other waste streams come close to meeting.
Other industries just release their wastes and toxins directly into the air, simply heap them into piles like coal ash or carelessly shallow-bury them. Depleting earth's reserves of valuable hydrocarbons, destabilizing the planet's climate, and lacing soil and water all over the world with toxins like mercury and arsenic; now THAT's a gift to future generations!
If one is concerned about overall public health and safety, as well as the climate, the way to help is not to nitpick about tiny nuclear-power-related risks or try to make tiny nuclear-related risks even smaller. Even solar and wind power pose larger risks than the ones these researchers seem to be so concerned about. The only real issue nuclear power has is cost, and almost all research efforts should be directed at bringing nuclear power costs down.
THAT is how you reduce public health risks. Dennis Huber March 31, PM. It is really straightforward to resolve the spent fuel issue. Reprocess the spent fuel into four product streams - transuranics that go to a burner or breeder reactor, fission products that are further separated into short lived less than 33 years that can be vitrified and stored for years or so at Yucca Mountain, and the seven bad actor fission products with long half lives that need to be sent to the burner reactor.
The fourth stream - the rest of the "waste" - is Uranium dioxide, and the deficit mass from the fission products and transuranics can be filled with weapons grade U or Pu from US or former Soviet Union weapons such that the resulting average enrichment is sufficient to use the entire lot to power another nuclear reactor without having to mine additional uranium for an extended time.
We should eliminate our wasteful once-through practice and deal with the problem we have created, not pass it onto the next generation. Certainly I have simplified this: there are small issues with this approach few technical, mostly regulatory , but it is much better than the alternative - which is continue to do nothing. Noel Wauchope March 30, PM. Look, this is a really informative and interesting article.
Steven Curtis March 30, PM. Great article, however, recycling should be explored more in-depth. Purniah is right about recycling commercial used nuclear fuel, however, taking out medical radioisotopes must be done quickly for them to be useful. No process plans to do so yet, but it would be great if it could happen. Nevertheless, getting the remaining power from material currently considered waste should not be ignored.
Shane Broussard March 31, AM. We should be recycling the fuel as much as possible. Continuing to study the problems and doing nothing is what has been done for decades. There is no way to guarantee any storage solution for millenia.
Get off the pot and put this stuff in Yucca mountain. Or why not just drop these storage containers into the ocean above the Mariana' Trench? Cowan March 31, AM. The Vermont Yankee casks in the page-top photo could I suppose be considered a one-deep pile. Years ago, both gas and uranium prices were much higher, and government's loss was accordingly greater.
Otherwise said, it's down fold. Dallas March 31, PM. Or we could consume all that waste in a next gen reactor and provide years of safe, carbon free electricity and process heat. Jacob D. Paz March 31, PM. Both the scientific community and the state of the Nevada have challenged the proposed high nuclear waste repository at Yucca Mountain, Nevada based on scientific and legal grounds. There is uncertainty as to whether the engineering barrier system will be corroded.
There are two major corrosion concerns: electrochemical corrosion and microbial induced corrosion. All the corrosion studies at Yucca Mountain were conducted in laboratories due to the chemical and geological complexity of YMP, which raises serious questions. In order to evaluate properly how the repository will comply with regulatory requirements, the DOE should have conducted long-term studies in real-world conditions prior to the approval of YMP.
In addition, the DOE did not incorporate into their computer model deliquescence corrosion. Why were no studies of the coefficient of distribution of radionuclides and heavy metals submitted. Imfene Endala April 1, PM. The salt is waterproof and plastic. So the containers will eventually be completely encapsulated and water ingress will not be a worry.
Spent fuel in Finland will be entombed in a hardrock mine. In France they want to bury it in clay. Water doesn't move in clay. While these materials will be radioactive for a very long time, within a years they will have decayed to a level where they are not all that dangerous any more.
Of course they will still be toxic, but Lead, Arsenic, Copper and Mercury and even some man made materials will also be toxic forever. We dig up metal tools and ornaments that are lots older than a years so I can not see any reason why we can not make containers that will outlast this period. This problem was solved in the late 50's. I saw the research. Bury in a salt dome, of which the U. It is entombed and gone forever.
All other "solutions" are just jobs programs. Joe Atkinson April 19, PM. One solution is to load the waste in a rocket and shoot it into the sun. This is currently unacceptable because of the fear that a rocket malfunction and drop a load of radioactive waste back on earth.
A scientific solution is to find a controlled way of doing nuclear reactions on a kilogram scale and so convert radioactive waste into non-radioactive elements.
I am an organic chemist and have no idea of even where to start. Claudia Tregoning October 25, AM. I live in South Australia.
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