Reprocessing Nuclear Fuel - Essay Example

Reprocessing Nuclear Fuel By Introduction The nuclear power generation and other applications of nuclear fission and corresponding nuclear technology including the researches in the fields of medicine generates radioactive wastes as byproducts The wastes that results from nuclear fuels are not necessarily hazardous or hard to manage. Such wastes can be treated as waste or used as valuable materials for production (Toth, 2011, pp312-378). The radioactive wastes are normally kept in unexposed condition for a particular period to allow for them to decay in order to reduce their radio nuclide. Radio nuclide is a major composite of the radioactive waste. Handling of the radioactive wastes is dependent on the time taken for half the atoms of the radionuclides to decay. The wastes with long half-life are easier to handle compared to those wastes with short half-life. Reprocessing of nuclei waste is mainly objected to safeguarding human population and the environment prior to releasing the wastes to the environment. This process mainly reduces the radionuclides concentrations in the waste, which are presumed harmless. Common radioactive wastes are categorized into very low level wastes, low level wastes, intermediate level wastes and high level wastes. Very low level wastes contain radioactive material at concentrations accepted not to be harmful to human population and the surrounding environment, main components are materials of: concrete, plaster, bricks, metals, valves and piping produced during operations, some food processing industries chemical industries and industries dealing in steel also produce this levels because of the natural radioactivity in the manufacturing process (Nikitin, Andrews & Holt, 2009, pp112- 167). Low level wastes are mainly generated from hospitals, nuclear fuel cycles and industries, they include: clothing, filters, papers and rags that mostly contains radioactivity with short lifes.They can be buried at shallow level, they doesn’t require shielding during handling and transportation. The wastes are compacted and incinerated before getting disposed. Low level wastes can comprise 90% volume but only 1% of the radioactivity of all radioactive waste. Intermediate level waste contain higher amounts of radioactivity, mainly comprise resins chemical sludge, metal fuel claddings and contaminated materials from reactor decommissioning.in handling these wastes the smaller once and those non solids can be solidified in concrete or bitumen to dispose, some of the intermediate level wastes requires shielding.7% of the intermediate level waste contains an estimate 4% of radioactivity (Nikitin, Andrews & Holt, 2009, pp112- 167). High level waste are radioactive wastes with the highest concentrations, they comes from burning of uranium fuel in a nuclear reactor .they contains fission products and also transuranic elements produced from the reactions the high level waste are very radioactive and hot and therefore mostly requires cooling and shielding on handling. These level wastes comprise 95% of the total radioactivity generated in processes of electricity generation. Reprocessing nuclear fuel is carried out in two main ways mainly waste disposal and transportation. 1. Waste disposal The main concern in waste disposal is managing the process safely. Disposal of nuclear wastes is manageable because of the small quantities of the wastes. Several disposal techniques are available and the dangers decreases with time according to radioactive decay.Waste in small quantities can be disposed in engineered structures, mined cavities, in deep geological repositories and small near surface pits (Carron, Khromov & Parish, 1999, pp157-217). For large nuclear wastes the disposal means can include disposal directly into the atmosphere while some can be disposed by burring the wastes in shallow grounds, launchingintospace, transmuting into accelerators or reactors deep salt beds that is free of water itself seals and flows from waste decay heat to plasticity that seals the waste if their concentrations are not considered harmful (Nikitin, Andrews & Holt, 2009, pp112- 167). Common processes involved in nuclear processing of the waste disposal include purex, Urex, Truex, Diamex, Sanex, andUnex. Purex is considered as the most method and stands to Plutonium and Uranium Recovery by Extraction. The process mainly involves a liquid –liquid extraction method and utilized in manufacturing of the second processing of the nuclear fuel when extracting uranium and plutonium separately other than fission products (Tumanov, 2003, pp47-89). Purex method contains massive PU-240 when utilized as fuels from commercial power reactorsthat can be utilized in nuclear weaponsUrex is the Uranium Extraction process and it is utilized in saving space within high level radioactive disposal sites. Extraction process of Urex is undertaken byremoving the uranium, which mainly comprises of the major parts of the whole mass a volume and reprocessed uranium (Carron, Khromov & Parish, 1999, pp157-217). Urex is normally preferred for Purex process restructured because it aids in prevention of prevent plutonium from being extracted. Moreover, Urex process for resistance toproliferation compared to Purex process. Truex is an abbreviation of the Trans Uranic Extraction that is mainly designed to aid in the removal of the transuranic metals from waste by lowering underlying alpha activity of the wastes with low alpha concentrations (Wiles, 2002, pp 56-167). Truex aids in making nuclear waste disposal much easy. Diamex stands for Diamide Extraction and it is renowned extraction process utilized manufacturing of maladiamide. Diamex aids in preventing formation of organic wastes such as carbon hydrogen, whichare burnt without formation of acid gases. Combustion of carbon hydrogen results to formation of acid gases that are released to the atmosphere thus leading to acid rains. Sanex stands for Selective Actinide Extraction and acts as the main components of management structures of minor actinides (Nikitin, Andrews & Holt, 2009, pp112- 167). Lanthanides and trivalent minor actinides are normally removed by the processes of Purex and Truex. The lanthides are removedto allow actinides such as americium to be utilized in the industrial process and be applied fuels.Moreover,lanthanides normally poison neutron driven nuclear fission due to its massive neutron cross sections.Universal Extraction process mainly permits full removal of vigorousradioisotopes such as Sr., Cs, and minor actinides from complete removal of remains after extraction of uranium and plutonium then utilized as nuclear fuels. The chemical reactions are based on interaction ofcesium and strontium with polyethylene glycol. Electromagnetic process of nuclear waste disposal entails exchange in ammonium carbonate (Tumanov, 2003, pp47-89). Pyro processing mainly entail high temperature processes, solvents in their molten states. High temperatures processes entail LiCl+KCl or LiF+CaF2 and their correspondingmoltenmetals such as cadmium bismuth magnesia’s method. Cadmium is mainly utilized since its operation principles are easier to comprehend readily applied to high burning fuels and it requires less cooling. Nevertheless, the process is not applied in solvents containing hydrogen and carbon. The possess utilizedgas that is less preferred for conversion into glass than those produced by Purex thus demanding relatively better recovery Advantages of reprocessing as an aid to nuclear waste disposal Reprocessing wastes aids in reducing the environmental effects of the nuclear wastes. The process of reprocessing the nuclear wastes normally reduce nuclear waste disposal to low concentrations that are presumed to be less harmful to the environment (Tumanov, 2003, pp47-89). This makes the disposal of the wastes by either burring or releasing to space easier thus limiting the environmental hazard. Reprocessing the nuclear wastes reduces the accumulation levels of wastes thus aiding in the reduction of concentration of the nuclear waste such that the nuclear wastes released to the environment are in less harmful concentration. This correspondingly aids in easing the burden of responsibility from the future generations to be actively involved in management of the nuclear wastes Reprocessing nuclear wastes helpsin removal in managing the safety and security risks and ongoing costs recurring having to indefinitely maintenance and protection surface storage facilities for the materials, which has been hazardous for numerous year (Wiles, 2002, pp 56-167). Subsequent to reprocessing the waste they are can placed into other use the reprocess ion products. Reprocessed ion products are normally utilized as raw materials in medicine and in industries. Reprocessing helps in prevention in production of gases that burn without producing acid gases that normally results to acid rains. Reprocessing produces organic gases other than carbon, hydrogen, nitrogen and oxygengases that burnsafely (Nikitin, Andrews & Holt, 2009, pp112- 167). If the other gases like carbon hydrogen or nitrogen are produced they results into carbon or nitric gases that are acidic in nature if mixed with rain water forms acid rains that corrodes the metal structures. This is completely eliminated by reprocessing process of nuclear waste prior to their disposal. Disadvantages of reprocessing nuclear waste disposal Most of the reprocessing processes for handling nuclear wastes involve nuclear fission, which leads to production gamma rays emissions, the gamma rays in case they are not confined or properly shielded. Gamma rays are harmful to people and the environment. The gamma rays from nuclear wastes are cancerous in nature (Carron, Khromov & Parish, 1999, pp157-217). Reprocessing 239Pu which has a half-life of 24000 years can eliminate the neutron and that can be very harmful as the neutron is highly chemically toxic. There is danger of exposing future generations with accumulated waste disposals, in reprocessing the waste by reducing their chemical concentrations and then releasing to the space as a means of disposal can have a long term effect if the little concentrations accumulate over time There are significant uncertainties in regard to the safety of utilizing geological repositories, the host rocks that are affected by the buried thermally hot wastes.The disposal of high level nuclear wastes is subject to numerous natural disasters’ to manmade structures suchas dams, which are susceptible to failure. 2. Transportation of nuclear wastes Transportation of the nuclear wastes mainly entails movements of the materials between facilities. Transport is a major contributor in the nuclear cycle since they are few nuclear power reactors (430) operated in 36 countries where mining of the minerals only viable in fewer regions. Thus, transportation facilitates for movement of the raw materials to the nuclear reactor and transportation of the nuclear waste to the reprocessing sites and then final transport to disposal sites are significant in the reprocessing nuclear fuels. Some of the major considerations in transportation of the reprocessed nuclear waste include packaging, radiation protection and corresponding environment protection. Packaging aids in maintaining safety during the transportation of the nuclear materials thus packaging plays the major role. Packagers ought to always take into consideration the consequence of the accidental risks that may come by in the course of transportation (Tumanov, 2003, pp47-89). The packaging of the nuclear materials depends on the potential hazards from the materials and therefore, varies from material to material. Some of the main material specifications that are commonly utilized in the packaging include containers from ordinary industries that aremainly used to transport low-level nuclear materials such as uranium oxide concentrate (U3O8). Type A containers are used medium activity materials such as medical radioisotopes or industrial radioisotopes since they can withstand minor accidents. Type B containers such asHotec’s HI-STAR *80 cask are used for high-level wastes and they range from drums to truck size containers (Nikitin, Andrews & Holt, 2009, pp112- 167). Hotec’s HI-STAR *80 cask are designed to offer safety from gamma radiation and radioisotopes. Type C containers are used to transport small amounts of high-activity materials, which are commonly transported by airs and they are capable of granting additionalprotection in accident scenarios thus can survive being dropped at high altitude. Radiation protection aids in ensuring safety of the transporters, the general population living along the transportation line and the environment thus ought to be maintained. Inthe process of enhancing protection shielding is normally offered in order to reduce the exposure to radiation (Carron, Khromov & Parish, 1999, pp157-217). Low-level materials with low radiations demands no shielding whilst high level wastes requires high design containers that are offered with integral shielding. This is due to the production of highly radioactive radiations. In the process of managing the risks of radiation dual-purpose containers is always appropriate for both storage and transportation (Wiles, 2002, pp 56-167).The whole the material on transit are normallylabeled indicating the levels of the radioactive substances in them. The transporters involved in transportation of the radioactive materials ought to be trained on the necessary precautions and how to act in case of emergency (Nikitin, Andrews & Holt, 2009, pp112- 167).The containers to transport the radioactive materials must be designed to retain the expectations of adhering to the environmental uncertainties like fire, heat, cold condition impacts, pressure and wetting. The packages must always be inspected before shipping. This aids in enhancing of the Environmental protection Reprocessing of nuclear fuel is the process of separating possibly fissile content of spent nuclear fuel majorly the content called plutonium via the utilization of chemical and physical and chemical in a nuclear for the purposes of recycling nuclear fuel (Tumanov, 2003, pp47-89). The whole process aims at deriving more energy from any original material containing uranium and thus protects the nuclear energy sustainability for a given country. The history of the U.S states that reprocessing started a long time ago and it was to single out plutonium from the irradiated uranium fuels rods to be used for the manufacture of atomic bombs (Case, 2011, pp234-289). The term transportation is used to imply the general movement of the radioactive or nuclear materials from the nuclear reactors to the facilities where the reprocessing takes place (reprocessing facilities). This facilities could be located within a country or oversees and thus for the former major problems are likely to arise during the transportation process. Used fuels from a nuclear reactor contain about 1% plutonium, 3% fission products coming from the nuclear reactor and 96% uranium (Carron, Khromov & Parish, 1999, pp157-217). This spent fuel has great emissions of radiation and heat and hence need some specialized kind of storage before transportation to the reprocessing facilities (Nikitin, Andrews & Holt, 2009, pp112- 167). They are first stored next to the reactors in water pools to allow for the cooling off of heat and the reduction in the radiation levels. This used fuel needs to be stored on the nuclear site for not less than five months. In this section we will provide a review of the pros and cons of the transportation process of these nuclear materials to be reprocessed and the final products. Regulation of transport of nuclear waste The international Atomic Agency since the 1961 published regulations for safe transportation of the nuclear materials (Case, 2011, pp234-289). The regulations mainly apply for both national and international transport and the regulations are always revised to keep them up to date the latest publish being the 2009 edition TS-R-1 regulation for the safe transport of radioactive material. Transportation of low-level and intermediate-level wastes Low level and intermediate level wastes are produced in the processes of radioisotopes used in medicine and in industries (Tumanov, 2003, pp47-89). Moreover, low-level radioactive wastes emit low levels of radiation and are always transported to storage or treatment plants. The low level wastes produce low level radiations include solid materials such as clothing, contaminated soils and tools thus their packaging does not require shielding and are commonly transported in drums. The intermediate-level wastes, which originate from nuclear power plants and reprocessing plants demands shielding and can be transported by roads, rail and sea transport. The common drums mainly used have capacities 200 liters of materials (Lochbaum, 1996, pp156-178). Transportation of high-level nuclear wastes High level nuclear wastes are considered as level nuclear waste emit high levels of radiation and heat since they contains 96%uranium 1%plutonium and 3% of fission products. They emit heatand are always kept in water pools to reduce the heat prior to their transportation where they are kept for a period of five months. High level nuclear wastes can either be transported by road rail or sea. The main containers used in transportation of high level nuclear wastes are type B containers. Transporting plutonium Transportation of plutonium isseparated during reprocessing and utilized nuclear fuels then mixed into oxide fuels. Plutonium is always transported after reprocessing it into oxide powder which is its most stable form (Carron, Khromov & Parish, 1999, pp157-217). The resultant oxide is insoluble in water and can be hazardous to human if it gets to the lungs. The platinum oxides are with special protection measures, the containers holds weights of up to 200kg from 80 kg. Advantages There are various types of radioactive or nuclear wastes to be reprocessed and the nature of each waste affects its transportation to the reprocessing sites (Toth, 2011, pp312-378). Low level waste commonly referred to as LLW contains sufficient quantities that do not warrant extraordinary shielding during its transportation. For the production of a specific amount of electricity the quantity of nuclear fuel required and thus the quantity of used materials to be reprocessed is less than any other fuel (Case, 2011, pp234-289). This is useful to the transportation of these materials to be recycled in that the potential risks and effect to the environment and the effects to the general public associated with the movement of such materials to the reprocessing plants are significantly reduced. Transportation of spent fuels or radioactive waste is a process that involves the movement of huge nuclear materials in many consignments of all sizes over vast distances (Toth, 2011, pp312-378). Minor accidents have occurred over the years since 1971 but there is no evidence that there have been any accidents involving the leakage of the radiations emitting from these wastes that arise from these highly reacting materials (Lochbaum, 1996, pp156-178). This is because the transportation of these materials is well regulated to minimize instances of leaks or breaches. The regulations are contained in the “Safety Regulations for the Transport of Radioactive Material” document. The IAEA Transport Regulations also control the package of the radioactive materials to be transported to the reprocessing facilities. Also followed are the “Regulations for the Safe Transport of Radioactive Material 2005 TS-R-1” which regulate the type of radioactive or spent fuel materials to be transported with regard with their potential hazard to the environment along the transport route. IAEA also designate the type of packages to transport any specific type of radioactive material. The excepted packages are aimed to transport small amounts of these materials (Lochbaum, 1996, pp156-178). The industrial packages are design to move materials of considerably low activity of radioactive emissions. Type A packages transport radioactive materials of restricted radioactivity. Type B are the packages that transport large amount of used nuclear fuel and high level wastes. All these regulations make the transportation process of spent fuels a safe process that is not detrimental to the immediate environment around the transport route (Case, 2011, pp234-289). This process is thus a safe process for movement of huge amounts of spent nuclear fuels to the reprocessing sites. The United States Nuclear Regulation Commission has reported that the safety of the shipments transportation of spent fuels is appreciable. Over the past 30 years there have been no injuries reported as a result of release of emissions by these materials. Transportation of the spent fuel is comparatively cheaper than building new respiratory sites near the nuclear reactor cells that require costly and expensive equipment. This is because the separation of the materials such as uranium, plutonium and other probable isotopes needs only small quantities of the waste to be transported to the respective reprocessing sites. It is also evident that the risk posed by fuel shipments in large scale needed for fossil fuels, which occasionally cause death and large scale detrimental effects to the environment show a larger cost to the whole society than the possible risks of transportation of spent fuels to the reprocessing sites (Lochbaum, 1996, pp156-178). There have been public outcries in the past about the potential environmental impacts of transporting spent fuels. It is worthwhile noting that there is a trail of barriers between the materials to be transported in casks and the environment that are built to the intended regulations to ensure safety of the environment (Case, 2011, pp234-289). Many studies carried around have shown that even in the case of a damage of a cask in a marine accident, the effect induced to the environment and to the public is of negligible significance as compared to the damage that may occur due to background radiations. Disadvantages The most cumbersome part of transportation of used fuels is the public figure and restrictions in the political and institutional circles. Transportation of used nuclear fuels to the reprocessing especially across recognized national divides or boundaries is subjected to political interference because the issues arising from spend nuclear fuel and waste transportation in general differs from country to country(Case, 2011, pp234-289) . For instance, the movement of the spent fuels to the reprocessing sites in Japan is less costly, less cumbersome and less likely to arouse a controversy which is the opposite case of the situation in the United States. This is because the transportation of these materials is by sea in ships with casks that are specially made for the purpose of carrying these spent fuels without the likelihood of accidents or accidental radiation emissions. The problem now comes in transportation of the materials way far oversees for instance from Japan to Europe. This is expensive and there is likelihood of political differences since the goods pass across the shores of many nations before they reach Europe. Intermediate level waste (ILW) and high level waste (HLW) require special treatment during transportation. They both require that the transportation facilities be equipped with shielding devices to prevent the emission of rays during transportation that has adverse effects on the public and the environment as a whole. Shielding is costly and thus makes the transportation process expensive. In addition the high level wastes require cooling facilities. The transportation of wastes generated at the reprocessing facilities to disposal sites is a complex process that entails the use of licensed shipping containers (casks), the media of transportation (barges, trains or trucks) and the specific routes the wastes will be carried in order to avoid effects to the society and the environment (Tumanov, 2003, pp47-89). The process of ensuring the safe disposal of these wastes is a time consuming and a strictly monitored and thus is viewed as a disadvantage. Another danger posed to transportation is the likelihood of theft of the spent fuel stored or a threat purposed to spread the contamination of a radioactive material (Lochbaum, 1996, pp156-178). These are security issues that affect transportation and though countries like Japan and the United States have regulations set for security measures, these issues are not easy to shake off and these threats occur occasionally (Case, 2011, pp234-289). There are studies suggesting that these regulations are inadequate and thus the difficulty in handling such crisis. The main disadvantage of transporting spent fuel is the cost incurred. This cost is dependent on; the amount of material, the distance to be covered, the security levels and the transportation mode used (Tumanov, 2003, pp47-89). It is generally expensive to transport such spent fuels as studies have shown. In 1994 the cost was estimated at 50 US Dollars/kgHM for transportation in parts of Europe, a study conducted by Nuclear Energy Agency of the Organization for Economic Cooperation. Transportation across oversees is more costly than transportation within a country for instance in Japan where there is reuse of already used casks. Conclusion Reprocessing nuclear fuel has numerous economic advantages in regard to the direct waste disposal. This could eradicate expenditure on the newly produced uranium fuel and corresponding degree of importance of life of the uranium resources (Tumanov, 2003, pp47-89). Moreover, reprocessing of nuclear waste saves money on the long-term storage by reducing the underlying size of the repository essential to handle spent nuclear fuel and rescheduling the requirement to expand such facility in the future. Formal cost benefit analysis of the nuclear fuel reprocessing is cumbersome prospect because of the massive uncertainties that mainly entail long term waste management and corresponding costs of reprocessing within US. Arguments that surround reprocessed nuclear waste mainly entail unacceptable explosion risks which can be evaded. In curbing explosion Risks Company have resort to using particular proliferation resistant methods of the reprocessing that mainly entail UREX (Carron, Khromov & Parish, 1999, pp157-217). Nevertheless, pyro processing is seen as the best processing for eliminating any uncertainties that surround reprocessing process of the nuclear fuels. Building of an aqueous solvent extraction plant cans also aids in radiation and environmental protections in regard to reprocessing of the nuclear fuel. Pyro processing effectivelyproduces no wastes and it is undertaken on site thus offering alternatives for fabricating proliferation resistant fuel from the corresponding plutonium and uranium. Nevertheless, role of nuclear power within US have reduced in the whole projections and the corresponding market price of the uranium have also declined. Dry storage during transportation of the nuclear fuel by the Nuclear Regulatory Commission in numerous sites have made it easy for reprocessing of the waste dispose and corresponding transportation, which normally have myriad of merit and demerits. Introduction of the new fuel cycle that mainly offers no importance environmental or waste disposal benefits normally contribute massively in regard to the industry. Nuclear reprocessing is environmentally hazardous and extremely expensive given the underlying present technological constraints and corresponding uranium prices even though this is drastically changing due to the scientific advancements (Wiles, 2002, pp 56-167). Perpetual government commitment in regard to researching pyro processing and other supplementary fuel cycle technologies is significant to the underlying nuclear industry particularly the envision of the technology that is being natured internationally. Bibliography Nikitin, M. B. D., Andrews, A., & Holt, M. (2009). Managing the nuclear fuel cycle: policy implications of expanding global access to nuclear power. Darby, Pa, Diane Publishing [for the Congressional Research Service]. Case, S. C. (2011). Proliferation risk in nuclear fuel cycles: workshop summary. 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