question: Is it possible to use split radioactive waste until it reaches a stable element?
comment: So if I was telling my five year old nephew why not - I'd say it is just way way easier and cheaper to collect the radioactive material and seal it underground in salt caverns and bury it in concrete. & #x200B; While it is possible, it would take so much energy that it would not be worth the endeavor. You could use a particle accelerator but the process would be very very very slow - think shooting 1-2 grains of sand/second at a wall to clean it from a compressed air source that takes a city block worth of electricity to run it. The big problem you have is there will not be a chain reaction of this nuclear material that is composed of a multitude of radioactive isotopes. & #x200B; This is the reason why Uranium needs to be enriched for a nuclear bomb though a lengthy process is to get it to an isotope that will when split and release so many neutrons that they will more than likely than not hit other Uranium isotopes, and they repeat the same, and so and and so on - making the famous nuclear chain reaction that is a nuclear bomb - also you have to have coordinated explosions that prompt a spherical implosion.
passages: Section::::Fuel cycles.:Minor actinides recycling.:Fuel or targets for this actinide transmutation.:Mixed matrix.
  
  It is also possible to create a matrix made from a mix of the above-mentioned materials. This is most commonly done in fast reactors where one may wish to keep the breeding ratio of new fuel high enough to keep powering the reactor, but still low enough that the generated actinides can be safely destroyed without transporting them to another site. One way to do this is to use fuel where actinides and uranium is mixed with inert zirconium, producing fuel elements with the desired properties.
  
  Section::::Fuel cycles.:Thorium cycle.
   In the US, several chemical exchange methods for lithium isotope separation have been under investigation in the 1930s and 1940s to develop a process for lithium-6 production, so that tritium could be obtained for thermonuclear weapons research.
   Transmutation of transuranium elements (TRUs, i.e. actinides minus actinium to uranium) such as the isotopes of plutonium (about 1wt% in the Light Water Reactors' used nuclear fuel (UNF)) or the minor actinides (MAs, i.e. neptunium, americium, and curium, about 0.1wt% each in LWRs' UNF) has the potential to help solve some problems posed by the management of radioactive waste by reducing the proportion of long-lived isotopes it contains. (This does not rule out the need for a Deep Geological Repository (DGR) for High radioactive Level Waste (HLW).) When irradiated with fast neutrons in a nuclear reactor, these isotopes can undergo nuclear fission, destroying the original actinide isotope and producing a spectrum of radioactive and nonradioactive fission products.
   Eu's large neutron capture cross section (about 3900 barns for thermal neutrons, 16000 resonance integral) means that most of even the small amount produced is destroyed in the course of the nuclear fuel's burnup. Yield, decay energy, and halflife are all far less than Cs and Sr, so Eu is not a significant contributor to nuclear waste.
   Section::::Techniques.:"In-situ" leaching.
  
  In-situ leaching (ISL), also known as solution mining, or in-situ recovery (ISR) in North America, involves leaving the ore where it is in the ground, and recovering the minerals from it by dissolving them and pumping the pregnant solution to the surface where the minerals can be recovered. Consequently, there is little surface disturbance and no tailings or waste rock generated. However, the orebody needs to be permeable to the liquids used, and located so that they do not contaminate ground water away from the orebody.
   In nature, sixteen repositories were discovered at the Oklo mine in Gabon where natural nuclear fission reactions took place 1.7 billion years ago. The fission products in these natural formations were found to have moved less than 10 ft (3 m) over this period, though the lack of movement may be due more to retention in the uraninite structure than to insolubility and sorption from moving ground water; uraninite crystals are better preserved here than those in spent fuel rods because of a less complete nuclear reaction, so that reaction products would be less accessible to groundwater attack.
   The waste stream from the SSR will be in the form of solid salt in tubes. This can be vitrified and stored underground for over 100,000 years as is planned today, or it can be reprocessed. In that case, fission products would be separated out and safely stored at ground level for the few hundred years needed for them to decay to levels similar to uranium ore. The troublesome long-lived actinides and the remaining fuel would go back into the reactor where they to be burnt and transmuted into more-stable isotopes.
  
  Section::::Other stable salt reactor designs.
   Disposal of expired radioactive sources presents similar challenges to the disposal of other nuclear waste, although to a lesser degree. Spent low level sources will sometimes be sufficiently inactive that they are suitable for disposal via normal waste disposal methods — usually landfill. Other disposal methods are similar to those for higher-level radioactive waste, using various depths of borehole depending on the activity of the waste.
  
  A notorious incident of neglect in disposing of a high level source was the Goiânia accident, which resulted in several fatalities.
  
  Section::::See also.
  
  BULLET::::- Common beta emitters
  
  BULLET::::- Commonly used gamma-emitting isotopes
   There have also been theoretical studies involving the use of fusion reactors as so called "actinide burners" where a fusion reactor plasma such as in a tokamak, could be "doped" with a small amount of the "minor" transuranic atoms which would be transmuted (meaning fissioned in the actinide case) to lighter elements upon their successive bombardment by the very high energy neutrons produced by the fusion of deuterium and tritium in the reactor. A study at MIT found that only 2 or 3 fusion reactors with parameters similar to that of the International Thermonuclear Experimental Reactor (ITER) could transmute the entire annual minor actinide production from all of the light water reactors presently operating in the United States fleet while simultaneously generating approximately 1 gigawatt of power from each reactor.
   Some proposed reactor designs, such as the American Integral Fast Reactor and the Molten salt reactor can more completely use or burnup the spent reactor grade plutonium fuel and other minor actinides, generated from light water reactors, as under the designed fast fission spectrum, these elements are more likely to fission and produce the aforementioned fission products in their place. This offers a potentially more attractive alternative to deep geological disposal.
   Another approach termed Remix & Return would blend high-level waste with uranium mine and mill tailings down to the level of the original radioactivity of the uranium ore, then replace it in inactive uranium mines. This approach has the merits of providing jobs for miners who would double as disposal staff, and of facilitating a cradle-to-grave cycle for radioactive materials, but would be inappropriate for spent reactor fuel in the absence of reprocessing, due to the presence of highly toxic radioactive elements such as plutonium within it.
   Breeder reactors can run on U-238 and transuranic elements, which comprise the majority of spent fuel radioactivity in the 1,000–100,000-year time span.
  
  Section::::Management.:Long term management.:Space disposal.
   In-situ recovery involves the extraction of uranium-bearing water (grading as low as .05% UO). The extracted uranium solution is then filtered through resin beads. Through an ion exchange process, the resin beads attract uranium from the solution. Uranium loaded resins are then transported to a processing plant, where UO is separated from the resin beads and yellowcake is produced. The resin beads can then be returned to the ion exchange facility where they are reused.
   Section::::Artificial transmutation of nuclear waste.:Reasoning behind transmutation.
  
  Isotopes of plutonium and other actinides tend to be long-lived with half-lives of many thousands of years, whereas radioactive fission products tend to be shorter-lived (most with half-lives of 30 years or less). From a waste management viewpoint, transmutation (or "burning" or "incineration") of actinides eliminates a very long-term radioactive hazard and replaces it with a much shorter-term one.
   In the second half of the 20th century, several methods of disposal of radioactive waste were investigated by nuclear nations, which are :
  
  BULLET::::- "Long term above ground storage", not implemented.
  
  BULLET::::- "Disposal in outer space" (for instance, inside the Sun), not implemented - as it would be currently too expensive.
  
  BULLET::::- "Deep borehole disposal", not implemented.
  
  BULLET::::- "Rock-melting", not implemented.
  
  BULLET::::- "Disposal at subduction zones", not implemented.
   Unfortunately, both models fail to reproduce the tritium in river waters; thus, a two-member mixing model was developed that consists of 2 components: a prompt-flow component (recent precipitation – "piston") and a component where waters reside in the basin for longer than 1 year ("well-mixed reservoir"). Therefore, the basin tritium concentration becomes a function of the residence times within the basin, sinks (radioactive decay) or sources of tritium, and the input function.
   Transmutation was banned in the US in April 1977 by President Carter due to the danger of plutonium proliferation, but President Reagan rescinded the ban in 1981. Due to the economic losses and risks, construction of reprocessing plants during this time did not resume. Due to high energy demand, work on the method has continued in the EU. This has resulted in a practical nuclear research reactor called Myrrha in which transmutation is possible. Additionally, a new research program called ACTINET has been started in the EU to make transmutation possible on a large, industrial scale. According to President Bush's Global Nuclear Energy Partnership (GNEP) of 2007, the US is now actively promoting research on transmutation technologies needed to markedly reduce the problem of nuclear waste treatment.
   Traces of the minor actinides are present in spent reactor fuel. These are actinides other than uranium and plutonium and include neptunium, americium and curium. The amount formed depends greatly upon the nature of the fuel used and the conditions under which it was used. For instance, the use of MOX fuel (Pu in a U matrix) is likely to lead to the production of more Am and heavier nuclides than a uranium/thorium based fuel (U in a Th matrix).
   Depleted UO (DUO) can be used as a material for radiation shielding. For example, DUCRETE is a "heavy concrete" material where gravel is replaced with uranium dioxide aggregate; this material is investigated for use for casks for radioactive waste. Casks can be also made of DUO-steel cermet, a composite material made of an aggregate of uranium dioxide serving as radiation shielding, graphite and/or silicon carbide serving as neutron radiation absorber and moderator, and steel as the matrix, whose high thermal conductivity allows easy removal of decay heat.
   Radioactive nuclei are produced at ISOLDE by impinging a high energy beam of protons on a stationary target. There are a number of target materials depending on the desired final species. Collisions between the proton beam and the target produce a variety of fragments, which are extracted and filtered to yield the desired isotope. The time required for extraction places a lower limit on the half life of isotopes which can be produced by this method. Once extracted, the isotopes are directed either to one of several detectors, an isotope harvesting area, or to the REX accelerator for acceleration to higher energies.
   For instance, plutonium can be reprocessed into MOX fuels and transmuted in standard reactors. The heavier elements could be transmuted in fast reactors, but probably more effectively in a subcritical reactor which is sometimes known as an energy amplifier and which was devised by Carlo Rubbia. Fusion neutron sources have also been proposed as well suited.
  
  Section::::Artificial transmutation of nuclear waste.:Fuel types.
   Section::::Fuel cycles.:Minor actinides recycling.:Fuel or targets for this actinide transmutation.:Actinides in an inert matrix.
  
  The actinides will be mixed with a metal which will not form more actinides, for instance an alloy of actinides in a solid such as zirconia could be used.
  
  Section::::Fuel cycles.:Minor actinides recycling.:Fuel or targets for this actinide transmutation.:Actinides in a thorium matrix.
  
  Thorium will on neutron bombardment form uranium-233. U-233 is fissile, and has a larger fission cross section than both U-235 and U-238, and thus it is far less likely to produce higher actinides through neutron capture.
   Section::::Sources.:Nuclear fuel cycle.:Fuel composition and long term radioactivity.
  
  The use of different fuels in nuclear reactors results in different spent nuclear fuel (SNF) composition, with varying activity curves.
  
  Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different.
   There have been proposals for reactors that consume nuclear waste and transmute it to other, less-harmful or shorter-lived, nuclear waste. In particular, the Integral Fast Reactor was a proposed nuclear reactor with a nuclear fuel cycle that produced no transuranic waste and in fact, could consume transuranic waste. It proceeded as far as large-scale tests, but was then canceled by the US Government. Another approach, considered safer but requiring more development, is to dedicate subcritical reactors to the transmutation of the left-over transuranic elements.
   Classes of wastes are detailed in 10 C.F.R. § 61.55 Waste Classification enforced by the Nuclear Regulatory Commission, reproduced in the table below. These are not all the isotopes disposed of at these facilities, just the ones that are of most concern for the long-term monitoring of the sites. Waste is divided into three classes, A through C, where A is the least radioactive and C is the most radioactive. Class A LLW is able to be deposited near the surface, whereas Classes B and C LLW have to be buried progressively deeper.
  