97-504: The Rokkasho Nuclear Fuel Reprocessing Facility ( 六ヶ所村核燃料再処理施設 , Rokkasho Kakunenryō Saishori Shisetsu ) is a nuclear reprocessing plant with an annual capacity of 800 tons of uranium or 8 tons of plutonium . It is owned by Japan Nuclear Fuel Limited (JNFL) and is part of the Rokkasho complex located in the village of Rokkasho in northeast Aomori Prefecture , on the Pacific coast of
194-417: A Princeton University theoretical physicist, have urged Japan to stop spent fuel reprocessing." The fundamental objection to reprocessing—the separation of plutonium from spent power reactor fuel—is that the plutonium could be used in nuclear weapons. The plant in Rokkasho aims to be able to separate several tons of plutonium per year where a nuclear weapon requires only several kilograms. To mitigate this risk
291-508: A UREX ( UR anium EX traction) process which could be used to save space inside high level nuclear waste disposal sites, such as the Yucca Mountain nuclear waste repository , by removing the uranium which makes up the vast majority of the mass and volume of used fuel and recycling it as reprocessed uranium . The UREX process is a PUREX process which has been modified to prevent the plutonium from being extracted. This can be done by adding
388-405: A decollement . Extensional decollements can grow to great dimensions and form detachment faults , which are low-angle normal faults with regional tectonic significance. Due to the curvature of the fault plane, the horizontal extensional displacement on a listric fault implies a geometric "gap" between the hanging and footwalls of the fault forms when the slip motion occurs. To accommodate into
485-829: A plate boundary. This class is related to an offset in a spreading center , such as a mid-ocean ridge , or, less common, within continental lithosphere , such as the Dead Sea Transform in the Middle East or the Alpine Fault in New Zealand. Transform faults are also referred to as "conservative" plate boundaries since the lithosphere is neither created nor destroyed. Dip-slip faults can be either normal (" extensional ") or reverse . The terminology of "normal" and "reverse" comes from coal mining in England, where normal faults are
582-468: A byproduct. Because this could allow for weapons grade nuclear material , nuclear reprocessing is a concern for nuclear proliferation and is thus tightly regulated. Relatively high cost is associated with spent fuel reprocessing compared to the once-through fuel cycle, but fuel use can be increased and waste volumes decreased. Nuclear fuel reprocessing is performed routinely in Europe, Russia, and Japan. In
679-838: A chamber full of fluorine. This is known as flame fluorination; the heat produced helps the reaction proceed. Most of the uranium , which makes up the bulk of the fuel, is converted to uranium hexafluoride , the form of uranium used in uranium enrichment , which has a very low boiling point. Technetium , the main long-lived fission product , is also efficiently converted to its volatile hexafluoride. A few other elements also form similarly volatile hexafluorides, pentafluorides, or heptafluorides. The volatile fluorides can be separated from excess fluorine by condensation, then separated from each other by fractional distillation or selective reduction . Uranium hexafluoride and technetium hexafluoride have very similar boiling points and vapor pressures, which makes complete separation more difficult. Many of
776-574: A fault hosting valuable porphyry copper deposits is northern Chile's Domeyko Fault with deposits at Chuquicamata , Collahuasi , El Abra , El Salvador , La Escondida and Potrerillos . Further south in Chile Los Bronces and El Teniente porphyry copper deposit lie each at the intersection of two fault systems. Faults may not always act as conduits to surface. It has been proposed that deep-seated "misoriented" faults may instead be zones where magmas forming porphyry copper stagnate achieving
873-500: A fault is locked, and when it reaches a level that exceeds the strength threshold, the fault ruptures and the accumulated strain energy is released in part as seismic waves , forming an earthquake . Strain occurs accumulatively or instantaneously, depending on the liquid state of the rock; the ductile lower crust and mantle accumulate deformation gradually via shearing , whereas the brittle upper crust reacts by fracture – instantaneous stress release – resulting in motion along
970-410: A fault often forms a discontinuity that may have a large influence on the mechanical behavior (strength, deformation, etc.) of soil and rock masses in, for example, tunnel , foundation , or slope construction. The level of a fault's activity can be critical for (1) locating buildings, tanks, and pipelines and (2) assessing the seismic shaking and tsunami hazard to infrastructure and people in
1067-408: A fault's age by studying soil features seen in shallow excavations and geomorphology seen in aerial photographs. Subsurface clues include shears and their relationships to carbonate nodules , eroded clay, and iron oxide mineralization, in the case of older soil, and lack of such signs in the case of younger soil. Radiocarbon dating of organic material buried next to or over a fault shear
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#17328767439151164-409: A fault. A fault trace or fault line is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A fault zone is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can blur the distinction, as
1261-476: A method for removing zirconium fuel cladding, instead of mechanical decladding. Chlorides are likely to be easier than fluorides to later convert back to other compounds, such as oxides. Chlorides remaining after volatilization may also be separated by solubility in water. Chlorides of alkaline elements like americium , curium , lanthanides , strontium , caesium are more soluble than those of uranium , neptunium , plutonium , and zirconium . To determine
1358-516: A neutron driven nuclear reaction. To date the extraction system for the SANEX process has not been defined, but currently several different research groups are working towards a process. For instance the French CEA is working on a bis-triazinyl pyridine (BTP) based process. Other systems such as the dithiophosphinic acids are being worked on by some other workers. The UN iversal EX traction process
1455-518: A plutonium reductant before the first metal extraction step. In the UREX process, ~99.9% of the uranium and >95% of technetium are separated from each other and the other fission products and actinides . The key is the addition of acetohydroxamic acid (AHA) to the extraction and scrub sections of the process. The addition of AHA greatly diminishes the extractability of plutonium and neptunium , providing somewhat greater proliferation resistance than with
1552-928: A smaller plant at West Valley Reprocessing Plant which closed by 1972 because of its inability to meet new regulatory requirements. Reprocessing of civilian fuel has long been employed at the COGEMA La Hague site in France, the Sellafield site in the United Kingdom, the Mayak Chemical Combine in Russia, and at sites such as the Tokai plant in Japan, the Tarapur plant in India, and briefly at
1649-446: A solid aluminium cathode. As an alternative to electrowinning, the wanted metal can be isolated by using a molten alloy of an electropositive metal and a less reactive metal. Since the majority of the long term radioactivity , and volume, of spent fuel comes from actinides, removing the actinides produces waste that is more compact, and not nearly as dangerous over the long term. The radioactivity of this waste will then drop to
1746-482: A vacuum. If a carrier salt like lithium fluoride or sodium fluoride is being used as a solvent, high-temperature distillation is a way to separate the carrier salt for reuse. Molten salt reactor designs carry out fluoride volatility reprocessing continuously or at frequent intervals. The goal is to return actinides to the molten fuel mixture for eventual fission, while removing fission products that are neutron poisons , or that can be more securely stored outside
1843-501: Is a generic term for high-temperature methods. Solvents are molten salts (e.g. LiCl + KCl or LiF + CaF 2 ) and molten metals (e.g. cadmium, bismuth, magnesium) rather than water and organic compounds. Electrorefining , distillation , and solvent-solvent extraction are common steps. These processes are not currently in significant use worldwide, but they have been pioneered at Argonne National Laboratory with current research also taking place at CRIEPI in Japan,
1940-459: Is an obsolete process that adds significant unnecessary material to the final radioactive waste. The bismuth phosphate process has been replaced by solvent extraction processes. The bismuth phosphate process was designed to extract plutonium from aluminium-clad nuclear fuel rods , containing uranium. The fuel was decladded by boiling it in caustic soda . After decladding, the uranium metal was dissolved in nitric acid . The plutonium at this point
2037-424: Is applied, causing the uranium metal (or sometimes oxide, depending on the spent fuel) to plate out on a solid metal cathode while the other actinides (and the rare earths) can be absorbed into a liquid cadmium cathode. Many of the fission products (such as caesium , zirconium and strontium ) remain in the salt. As alternatives to the molten cadmium electrode it is possible to use a molten bismuth cathode, or
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#17328767439152134-461: Is decreased. Most of the plutonium and some of the uranium will initially remain in ash which drops to the bottom of the flame fluorinator. The plutonium-uranium ratio in the ash may even approximate the composition needed for fast neutron reactor fuel. Further fluorination of the ash can remove all the uranium, neptunium , and plutonium as volatile fluorides; however, some other minor actinides may not form volatile fluorides and instead remain with
2231-463: Is free from uranium and contains recovered transuranics in an inert matrix such as metallic zirconium . In the PYRO-B processing of such fuel, an electrorefining step is used to separate the residual transuranic elements from the fission products and recycle the transuranics to the reactor for fissioning. Newly generated technetium and iodine are extracted for incorporation into transmutation targets, and
2328-466: Is in the +4 oxidation state. It was then precipitated out of the solution by the addition of bismuth nitrate and phosphoric acid to form the bismuth phosphate. The plutonium was coprecipitated with this. The supernatant liquid (containing many of the fission products ) was separated from the solid. The precipitate was then dissolved in nitric acid before the addition of an oxidant (such as potassium permanganate ) to produce PuO 2 . The plutonium
2425-543: Is often critical in distinguishing active from inactive faults. From such relationships, paleoseismologists can estimate the sizes of past earthquakes over the past several hundred years, and develop rough projections of future fault activity. Many ore deposits lie on or are associated with faults. This is because the fractured rock associated with fault zones allow for magma ascent or the circulation of mineral-bearing fluids. Intersections of near-vertical faults are often locations of significant ore deposits. An example of
2522-516: Is stored at Rokkasho. Since 1993 there has been US$ 20 billion invested in the project, nearly triple the original cost estimate. A 2011 estimate put the cost at US$ 27.5 billion. In May 2006, an international awareness campaign about the dangers of the Rokkasho reprocessing plant called "Stop Rokkasho" was launched by musician Ryuichi Sakamoto . Greenpeace Japan opposed the Rokkasho Reprocessing Plant and ran an online campaign to stop
2619-452: Is substantially different from the usual uranium or mixed uranium-plutonium oxides (MOX) that most current reactors were designed to use. Another pyrochemical process, the PYRO-B process, has been developed for the processing and recycling of fuel from a transmuter reactor ( a fast breeder reactor designed to convert transuranic nuclear waste into fission products ). A typical transmuter fuel
2716-517: Is that by lowering the alpha activity of the waste, the majority of the waste can then be disposed of with greater ease. In common with PUREX this process operates by a solvation mechanism. As an alternative to TRUEX, an extraction process using a malondiamide has been devised. The DIAMEX ( DIAM ide EX traction) process has the advantage of avoiding the formation of organic waste which contains elements other than carbon , hydrogen , nitrogen , and oxygen . Such an organic waste can be burned without
2813-450: Is very wide, but all agreed that under then-current economic conditions the reprocessing-recycle option is the more costly one. While the uranium market - particularly its short term fluctuations - has only a minor impact on the cost of electricity from nuclear power, long-term trends in the uranium market do significantly affect the economics of nuclear reprocessing. If uranium prices were to rise and remain consistently high, "stretching
2910-456: The Chesapeake Bay impact crater . Ring faults are the result of a series of overlapping normal faults, forming a circular outline. Fractures created by ring faults may be filled by ring dikes . Synthetic and antithetic are terms used to describe minor faults associated with a major fault. Synthetic faults dip in the same direction as the major fault while the antithetic faults dip in
3007-548: The West Valley Reprocessing Plant in the United States. In October 1976, concern of nuclear weapons proliferation (especially after India demonstrated nuclear weapons capabilities using reprocessing technology) led President Gerald Ford to issue a Presidential directive to indefinitely suspend the commercial reprocessing and recycling of plutonium in the U.S. On 7 April 1977, President Jimmy Carter banned
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3104-576: The bismuth phosphate process , was developed and tested at the Oak Ridge National Laboratory (ORNL) between 1943 and 1945 to produce quantities of plutonium for evaluation and use in the US weapons programs . ORNL produced the first macroscopic quantities (grams) of separated plutonium with these processes. The bismuth phosphate process was first operated on a large scale at the Hanford Site , in
3201-457: The diluent is a polar aromatic such as nitrobenzene . Other diluents such as meta -nitrobenzotri fluoride and phenyl trifluoromethyl sulfone have been suggested as well. An exotic method using electrochemistry and ion exchange in ammonium carbonate has been reported. Other methods for the extraction of uranium using ion exchange in alkaline carbonate and "fumed" lead oxide have also been reported. The bismuth phosphate process
3298-424: The fission products volatilized are the same ones volatilized in non-fluorinated, higher-temperature volatilization, such as iodine , tellurium and molybdenum ; notable differences are that technetium is volatilized, but caesium is not. Some transuranium elements such as plutonium , neptunium and americium can form volatile fluorides, but these compounds are not stable when the fluorine partial pressure
3395-549: The New York Times reported "...11 years after the government awarded a construction contract, the cost of the project has soared to nearly $ 5 billion. The vast concrete and steel structure is a half-finished hulk, and the government has yet to find a single customer, despite offers of lucrative subsidies." TVA (currently the most likely customer) said in April 2011 that it would delay a decision until it could see how MOX fuel performed in
3492-585: The Nuclear Research Institute of Řež in Czech Republic, Indira Gandhi Centre for Atomic Research in India and KAERI in South Korea. The electrolysis methods are based on the difference in the standard potentials of uranium, plutonium and minor actinides in a molten salt. The standard potential of uranium is the lowest, therefore when a potential is applied, the uranium will be reduced at
3589-472: The PUREX process, there have been efforts to develop alternatives to the process, some of them compatible with PUREX (i.e. the residue from one process could be used as feedstock for the other) and others wholly incompatible. None of these have (as of the 2020s) reached widespread commercial use, but some have seen large scale tests or firm commitments towards their future larger scale implementation. Pyroprocessing
3686-492: The Rokkasho spent fuel pool. According to The New York Times , grid power was restored 3 days later on 14 March 2011. The 7 April aftershock caused the loss of grid power again until the next day. 40°57′45″N 141°19′35″E / 40.96250°N 141.32639°E / 40.96250; 141.32639 Nuclear reprocessing Nuclear reprocessing is the chemical separation of fission products and actinides from spent nuclear fuel . Originally, reprocessing
3783-466: The United States, the Obama administration stepped back from President Bush's plans for commercial-scale reprocessing and reverted to a program focused on reprocessing-related scientific research. Not all nuclear fuel requires reprocessing; a breeder reactor is not restricted to using recycled plutonium and uranium. It can employ all the actinides , closing the nuclear fuel cycle and potentially multiplying
3880-403: The action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults . Energy release associated with rapid movement on active faults is the cause of most earthquakes . Faults may also displace slowly, by aseismic creep . A fault plane is the plane that represents the fracture surface of
3977-507: The alkaline fission products. Some noble metals may not form fluorides at all, but remain in metallic form; however ruthenium hexafluoride is relatively stable and volatile. Distillation of the residue at higher temperatures can separate lower-boiling transition metal fluorides and alkali metal (Cs, Rb) fluorides from higher-boiling lanthanide and alkaline earth metal (Sr, Ba) and yttrium fluorides. The temperatures involved are much higher, but can be lowered somewhat by distilling in
Rokkasho Reprocessing Plant - Misplaced Pages Continue
4074-582: The ban in 1981, but did not provide the substantial subsidy that would have been necessary to start up commercial reprocessing. In March 1999, the U.S. Department of Energy (DOE) reversed its policy and signed a contract with a consortium of Duke Energy , COGEMA , and Stone & Webster (DCS) to design and operate a mixed oxide (MOX) fuel fabrication facility. Site preparation at the Savannah River Site (South Carolina) began in October 2005. In 2011
4171-501: The cathode out of the molten salt solution before the other elements. These processes were developed by Argonne National Laboratory and used in the Integral Fast Reactor project. PYRO-A is a means of separating actinides (elements within the actinide family, generally heavier than U-235) from non-actinides. The spent fuel is placed in an anode basket which is immersed in a molten salt electrolyte. An electric current
4268-464: The completion date was put back again to 2022 for further safety measures including the construction of another cooling tower. The MOX fuel manufacturing plant is expected to be operational in 2024. As of 2023, JNFL claims an operational date of April–October 2024 The Rokkasho plant is the successor to a smaller reprocessing plant that was located in Tōkai, Ibaraki in central Japan which shutdown in 2014 and
4365-414: The crust. A thrust fault has the same sense of motion as a reverse fault, but with the dip of the fault plane at less than 45°. Thrust faults typically form ramps, flats and fault-bend (hanging wall and footwall) folds. A section of a hanging wall or foot wall where a thrust fault formed along a relatively weak bedding plane is known as a flat and a section where the thrust fault cut upward through
4462-433: The direction of extension or shortening changes during the deformation but the earlier formed faults remain active. The hade angle is defined as the complement of the dip angle; it is the angle between the fault plane and a vertical plane that strikes parallel to the fault. Ring faults , also known as caldera faults , are faults that occur within collapsed volcanic calderas and the sites of bolide strikes, such as
4559-404: The disadvantage of requiring the use of a salting-out reagent (aluminium nitrate ) to increase the nitrate concentration in the aqueous phase to obtain a reasonable distribution ratio. This process was used at Windscale in 1951-1964. This process has been replaced by PUREX, which was shown to be a superior technology for larger scale reprocessing. The sodium uranyl acetate process was used by
4656-681: The distribution of radioactive metals for analytical purposes, Solvent Impregnated Resins (SIRs) can be used. SIRs are porous particles, which contain an extractant inside their pores. This approach avoids the liquid-liquid separation step required in conventional liquid-liquid extraction . For the preparation of SIRs for radioanalytical separations, organic Amberlite XAD-4 or XAD-7 can be used. Possible extractants are e.g. trihexyltetradecylphosphonium chloride(CYPHOS IL-101) or N,N0-dialkyl-N,N0-diphenylpyridine-2,6-dicarboxyamides (R-PDA; R = butyl, octy I, decyl, dodecyl). The relative economics of reprocessing-waste disposal and interim storage-direct disposal
4753-557: The early Soviet nuclear industry to recover plutonium from irradiated fuel. It was never used in the West; the idea is to dissolve the fuel in nitric acid , alter the oxidation state of the plutonium, and then add acetic acid and base. This would convert the uranium and plutonium into a solid acetate salt. Explosion of the crystallized acetates-nitrates in a non-cooled waste tank caused the Kyshtym disaster in 1957. As there are some downsides to
4850-424: The energy extracted from natural uranium by about 60 times. The potentially useful components dealt with in nuclear reprocessing comprise specific actinides (plutonium, uranium, and some minor actinides ). The lighter elements components include fission products , activation products , and cladding . The first large-scale nuclear reactors were built during World War II . These reactors were designed for
4947-409: The fault (called a piercing point ). In practice, it is usually only possible to find the slip direction of faults, and an approximation of the heave and throw vector. The two sides of a non-vertical fault are known as the hanging wall and footwall . The hanging wall occurs above the fault plane and the footwall occurs below it. This terminology comes from mining: when working a tabular ore body,
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#17328767439155044-532: The fault is the vertical component of the separation and the heave of the fault is the horizontal component, as in "Throw up and heave out". The vector of slip can be qualitatively assessed by studying any drag folding of strata, which may be visible on either side of the fault. Drag folding is a zone of folding close to a fault that likely arises from frictional resistance to movement on the fault. The direction and magnitude of heave and throw can be measured only by finding common intersection points on either side of
5141-461: The fault movement. Faults are mainly classified in terms of the angle that the fault plane makes with the Earth's surface, known as the dip , and the direction of slip along the fault plane. Based on the direction of slip, faults can be categorized as: In a strike-slip fault (also known as a wrench fault , tear fault or transcurrent fault ), the fault surface (plane) is usually near vertical, and
5238-406: The fault. A fault in ductile rocks can also release instantaneously when the strain rate is too great. Slip is defined as the relative movement of geological features present on either side of a fault plane. A fault's sense of slip is defined as the relative motion of the rock on each side of the fault concerning the other side. In measuring the horizontal or vertical separation, the throw of
5335-428: The footwall moves laterally either left or right with very little vertical motion. Strike-slip faults with left-lateral motion are also known as sinistral faults and those with right-lateral motion as dextral faults. Each is defined by the direction of movement of the ground as would be seen by an observer on the opposite side of the fault. A special class of strike-slip fault is the transform fault when it forms
5432-531: The footwall. The dip of most normal faults is at least 60 degrees but some normal faults dip at less than 45 degrees. A downthrown block between two normal faults dipping towards each other is a graben . A block stranded between two grabens, and therefore two normal faults dipping away from each other, is a horst . A sequence of grabens and horsts on the surface of the Earth produces a characteristic basin and range topography . Normal faults can evolve into listric faults, with their plane dip being steeper near
5529-445: The formation of acidic gases which could contribute to acid rain (although the acidic gases could be recovered by a scrubber). The DIAMEX process is being worked on in Europe by the French CEA . The process is sufficiently mature that an industrial plant could be constructed with the existing knowledge of the process. In common with PUREX this process operates by a solvation mechanism. S elective A cti N ide EX traction. As part of
5626-414: The fuel or increases its surface area to enhance penetration of reagents in following reprocessing steps. Simply heating spent oxide fuel in an inert atmosphere or vacuum at a temperature between 700 °C (1,292 °F) and 1,000 °C (1,830 °F) as a first reprocessing step can remove several volatile elements, including caesium whose isotope caesium-137 emits about half of the heat produced by
5723-487: The fuel supply" via MOX fuel, breeder reactors or even the thorium fuel cycle could become more attractive. However, if uranium prices remain low, reprocessing will remain less attractive. Fault line In geology , a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth 's crust result from
5820-429: The geometric gap, and depending on its rheology , the hanging wall might fold and slide downwards into the gap and produce rollover folding , or break into further faults and blocks which fil in the gap. If faults form, imbrication fans or domino faulting may form. A reverse fault is the opposite of a normal fault—the hanging wall moves up relative to the footwall. Reverse faults indicate compressive shortening of
5917-491: The implied mechanism of deformation. A fault that passes through different levels of the lithosphere will have many different types of fault rock developed along its surface. Continued dip-slip displacement tends to juxtapose fault rocks characteristic of different crustal levels, with varying degrees of overprinting. This effect is particularly clear in the case of detachment faults and major thrust faults . The main types of fault rock include: In geotechnical engineering ,
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#17328767439156014-590: The industry at present. When used on fuel from commercial power reactors the plutonium extracted typically contains too much Pu-240 to be considered "weapons-grade" plutonium, ideal for use in a nuclear weapon. Nevertheless, highly reliable nuclear weapons can be built at all levels of technical sophistication using reactor-grade plutonium. Moreover, reactors that are capable of refueling frequently can be used to produce weapon-grade plutonium, which can later be recovered using PUREX. Because of this, PUREX chemicals are monitored. The PUREX process can be modified to make
6111-464: The largest faults on Earth and give rise to the largest earthquakes. A fault which has a component of dip-slip and a component of strike-slip is termed an oblique-slip fault . Nearly all faults have some component of both dip-slip and strike-slip; hence, defining a fault as oblique requires both dip and strike components to be measurable and significant. Some oblique faults occur within transtensional and transpressional regimes, and others occur where
6208-432: The later part of 1944. It was successful for plutonium separation in the emergency situation existing then, but it had a significant weakness: the inability to recover uranium. The first successful solvent extraction process for the recovery of pure uranium and plutonium was developed at ORNL in 1949. The PUREX process is the current method of extraction. Separation plants were also constructed at Savannah River Site and
6305-517: The level of various naturally occurring minerals and ores within a few hundred, rather than thousands of, years. The mixed actinides produced by pyrometallic processing can be used again as nuclear fuel, as they are virtually all either fissile , or fertile , though many of these materials would require a fast breeder reactor to be burned efficiently. In a thermal neutron spectrum, the concentrations of several heavy actinides ( curium -242 and plutonium-240 ) can become quite high, creating fuel that
6402-403: The management of minor actinides it has been proposed that the lanthanides and trivalent minor actinides should be removed from the PUREX raffinate by a process such as DIAMEX or TRUEX. To allow the actinides such as americium to be either reused in industrial sources or used as fuel, the lanthanides must be removed. The lanthanides have large neutron cross sections and hence they would poison
6499-408: The miner stood with the footwall under his feet and with the hanging wall above him. These terms are important for distinguishing different dip-slip fault types: reverse faults and normal faults. In a reverse fault, the hanging wall displaces upward, while in a normal fault the hanging wall displaces downward. Distinguishing between these two fault types is important for determining the stress regime of
6596-435: The most common. With the passage of time, a regional reversal between tensional and compressional stresses (or vice-versa) might occur, and faults may be reactivated with their relative block movement inverted in opposite directions to the original movement (fault inversion). In such a way, a normal fault may therefore become a reverse fault and vice versa. In a normal fault, the hanging wall moves downward, relative to
6693-482: The nitrate concentration in the aqueous phase to obtain a reasonable distribution ratio (D value). Also, hexone is degraded by concentrated nitric acid. This process was used in 1952-1956 on the Hanford plant T and has been replaced by the PUREX process. Pu + 4NO − 3 + 2S → [Pu(NO 3 ) 4 S 2 ] A process based on a solvation extraction process using the triether extractant named above. This process has
6790-444: The northernmost part of Japan's main island of Honshu . Construction of the plant began in 1993, and was originally expected to be completed in 1997, but the completion date has been postponed 23 times by 2017. Construction and testing of the facility were complete in 2013 according to JNFL, and the site was intended to begin operating in October 2013; however this was delayed by new safety regulations. In December 2013 JNFL announced
6887-413: The nuclear accident at Fukushima Daiichi . PUREX , the current standard method, is an acronym standing for P lutonium and U ranium R ecovery by EX traction . The PUREX process is a liquid-liquid extraction method used to reprocess spent nuclear fuel , to extract uranium and plutonium , independent of each other, from the fission products. This is the most developed and widely used process in
6984-482: The opposite direction. These faults may be accompanied by rollover anticlines (e.g. the Niger Delta Structural Style). All faults have a measurable thickness, made up of deformed rock characteristic of the level in the crust where the faulting happened, of the rock types affected by the fault and of the presence and nature of any mineralising fluids . Fault rocks are classified by their textures and
7081-431: The other fission products are sent to waste. Voloxidation (for volumetric oxidation ) involves heating oxide fuel with oxygen, sometimes with alternating oxidation and reduction, or alternating oxidation by ozone to uranium trioxide with decomposition by heating back to triuranium octoxide . A major purpose is to capture tritium as tritiated water vapor before further processing where it would be difficult to retain
7178-563: The petition to the Cabinet Office and the Ministry of Economy, Trade and Industry . Seven consumer organisations have joined in this effort: Consumers Union of Japan , Seikatsu Club Consumer's Co-operative Union, Daichi-o-Mamoru Kai, Green Consumer's Co-operative Union, Consumer's Co-operative Union "Kirari", Consumer's Co-operative Miyagi and Pal-system Co-operative Union. According to The Japan Times , "Experts including Frank von Hippel ,
7275-545: The plant to deteriorate, and the closure of the unsuccessful fast breeder reactor at Monju in 2016 reduces the need for the policy of nuclear fuel reprocessing. In August 2018 more corroded pipes were found. In 2018 the Japanese Atomic Energy Commission updated plutonium guidelines to try to reduce plutonium stockpiles, stipulating that Rokkasho should only produce the amount of plutonium required for mixed oxide fuel for Japan's nuclear plants. In 2020
7372-422: The plant uses a combined uranium plutonium extraction process where plutonium cannot be recovered by itself. In June 2008, several scientists stated that the Rokkasho plant is situated directly above an active geological fault line that could produce a magnitude 8 earthquake but Japan Nuclear Fuel Limited stated that according to their investigation the fault had not been active in the last million years and there
7469-471: The plant would be ready for operation in October 2014. In 2015, the start of the reprocessing plant was postponed again, this time to as late as September 2018. In December 2017, the completion date was put back a further three years, to 2021, to allow for further safety measures at the reprocessing plant and the MOX fuel fabrication plant to meet post-Fukushima safety standards. The delays have caused many parts of
7566-522: The plutonium extraction stage of the PUREX process. Adding a second extraction agent, octyl(phenyl)-N, N-dibutyl carbamoylmethyl phosphine oxide (CMPO) in combination with tributylphosphate, (TBP), the PUREX process can be turned into the TRUEX ( TR ans U ranic EX traction) process. TRUEX was invented in the US by Argonne National Laboratory and is designed to remove the transuranic metals (Am/Cm) from waste. The idea
7663-448: The plutonium. Addition of an alkali produced an oxide. The combined lanthanum plutonium oxide was collected and extracted with nitric acid to form plutonium nitrate. This is a liquid-liquid extraction process which uses methyl isobutyl ketone codenamed hexone as the extractant. The extraction is by a solvation mechanism. This process has the disadvantage of requiring the use of a salting-out reagent ( aluminium nitrate ) to increase
7760-413: The production of plutonium for use in nuclear weapons . The only reprocessing required, therefore, was the extraction of the plutonium (free of fission-product contamination) from the spent natural uranium fuel. In 1943, several methods were proposed for separating the relatively small quantity of plutonium from the uranium and fission products. The first method selected, a precipitation process called
7857-472: The project called "Wings of Peace – No more Hiroshima Nagasaki" from 2002 until 2005. The Consumers Union of Japan together with 596 organisations and groups participated in a march against the Rokkasho Reprocessing Plant in central Tokyo on 27 January 2008. Over 810,000 signatures were collected and handed in to the government on 28 January 2008. Representatives of the protesters, which included fishery associations, consumer cooperatives and surfer groups, handed
7954-540: The reactor core while awaiting eventual transfer to permanent storage. Many of the elements that form volatile high- valence fluorides will also form volatile high-valence chlorides. Chlorination and distillation is another possible method for separation. The sequence of separation may differ usefully from the sequence for fluorides; for example, zirconium tetrachloride and tin tetrachloride have relatively low boiling points of 331 °C (628 °F) and 114.1 °C (237.4 °F). Chlorination has even been proposed as
8051-415: The reprocessing of commercial reactor spent nuclear fuel . The key issue driving this policy was the risk of nuclear weapons proliferation by diversion of plutonium from the civilian fuel cycle, and to encourage other nations to follow the US lead. After that, only countries that already had large investments in reprocessing infrastructure continued to reprocess spent nuclear fuel. President Reagan lifted
8148-577: The reprocessing of other nuclear reactor material, such as Zircaloy cladding. The high radioactivity of spent nuclear material means that reprocessing must be highly controlled and carefully executed in advanced facilities by specialized personnel. Numerous processes exist, with the chemical based PUREX process dominating. Alternatives include heating to drive off volatile elements, burning via oxidation, and fluoride volatility (which uses extremely reactive Fluorine ). Each process results in some form of refined nuclear product, with radioactive waste as
8245-412: The right time for—and type of— igneous differentiation . At a given time differentiated magmas would burst violently out of the fault-traps and head to shallower places in the crust where porphyry copper deposits would be formed. As faults are zones of weakness, they facilitate the interaction of water with the surrounding rock and enhance chemical weathering . The enhanced chemical weathering increases
8342-411: The rock between the faults is converted to fault-bound lenses of rock and then progressively crushed. Due to friction and the rigidity of the constituent rocks, the two sides of a fault cannot always glide or flow past each other easily, and so occasionally all movement stops. The regions of higher friction along a fault plane, where it becomes locked, are called asperities . Stress builds up when
8439-459: The spent fuel over the following 100 years of cooling (however, most of the other half is from strontium-90 , which has a similar half-life). The estimated overall mass balance for 20,000 g of processed fuel with 2,000 g of cladding is: In the fluoride volatility process, fluorine is reacted with the fuel. Fluorine is so much more reactive than even oxygen that small particles of ground oxide fuel will burst into flame when dropped into
8536-416: The stratigraphic sequence is known as a ramp . Typically, thrust faults move within formations by forming flats and climbing up sections with ramps. This results in the hanging wall flat (or a portion thereof) lying atop the foot wall ramp as shown in the fault-bend fold diagram. Thrust faults form nappes and klippen in the large thrust belts. Subduction zones are a special class of thrusts that form
8633-400: The surface, then shallower with increased depth, with the fault plane curving into the Earth. They can also form where the hanging wall is absent (such as on a cliff), where the footwall may slump in a manner that creates multiple listric faults. The fault panes of listric faults can further flatten and evolve into a horizontal or near-horizontal plane, where slip progresses horizontally along
8730-506: The tritium. Tritium is a difficult contaminant to remove from aqueous solution, as it cannot be separated from water except by isotope separation. However, tritium is also a valuable product used in industry science and nuclear weapons , so recovery of a stream of hydrogen or water with a high tritium content can make targeted recovery economically worthwhile. Other volatile elements leave the fuel and must be recovered, especially iodine , technetium , and carbon-14 . Voloxidation also breaks up
8827-570: The vicinity. In California, for example, new building construction has been prohibited directly on or near faults that have moved within the Holocene Epoch (the last 11,700 years) of the Earth's geological history. Also, faults that have shown movement during the Holocene plus Pleistocene Epochs (the last 2.6 million years) may receive consideration, especially for critical structures such as power plants, dams, hospitals, and schools. Geologists assess
8924-464: Was approved for decommissioning in 2018. The Rokkasho facilities complex includes: In 2010, the Rokkasho complex consisted of 38 buildings on an area of 3,800,000 m. Vitrification tests were completed in November 2007. This consists of pouring high level dry waste residue along with molten glass into steel canisters. As of 2018, over a third of Japan's 10 metric tons of domestically held plutonium
9021-534: Was developed in Russia and the Czech Republic ; it is designed to completely remove the most troublesome radioisotopes (Sr, Cs and minor actinides ) from the raffinate remaining after the extraction of uranium and plutonium from used nuclear fuel . The chemistry is based upon the interaction of caesium and strontium with polyethylene glycol and a cobalt carborane anion (known as chlorinated cobalt dicarbollide). The actinides are extracted by CMPO, and
9118-405: Was maintained in the +6 oxidation state by addition of a dichromate salt. The bismuth phosphate was next re-precipitated, leaving the plutonium in solution, and an iron(II) salt (such as ferrous sulfate ) was added. The plutonium was again re-precipitated using a bismuth phosphate carrier and a combination of lanthanum salts and fluoride added, forming a solid lanthanum fluoride carrier for
9215-597: Was no reason to fear an earthquake of more than magnitude 6.5 at the site and that the plant could withstand a 6.9 quake. Other scientists say that more study is needed. After the Tōhoku earthquake (magnitude 9.1) on 11 March 2011, the plant ran on emergency power provided by backup diesel generators. The emergency generators were not intended for long-term use. There were about 3,000 tons of highly radioactive used nuclear fuel stored in Rokkasho at that time. Japanese radio reported on 13 March that 600 liters of water had leaked from
9312-400: Was the focus of much debate over the first decade of the 2000s. Studies have modeled the total fuel cycle costs of a reprocessing-recycling system based on one-time recycling of plutonium in existing thermal reactors (as opposed to the proposed breeder reactor cycle) and compare this to the total costs of an open fuel cycle with direct disposal. The range of results produced by these studies
9409-445: Was used solely to extract plutonium for producing nuclear weapons . With commercialization of nuclear power , the reprocessed plutonium was recycled back into MOX nuclear fuel for thermal reactors . The reprocessed uranium , also known as the spent fuel material, can in principle also be re-used as fuel, but that is only economical when uranium supply is low and prices are high. Nuclear reprocessing may extend beyond fuel and include
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