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1
Ojovan, Michael I., Rebecca A. Robbins y Miklos Garamszeghy. "Advances in conditioning of low- and intermediate-level nuclear waste". MRS Advances 3, n.º 19 (10 de diciembre de 2017): 983–90. http://dx.doi.org/10.1557/adv.2017.613.
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ABSTRACTRadioactive waste with widely varying characteristics is generated from the operation and maintenance of nuclear reactors, nuclear fuel cycle facilities, research facilities and medical facilities and the through the use of radioisotopes in industrial applications. The waste needs to be treated and conditioned appropriately to provide wasteforms acceptable for safe storage and disposal. Conditioning of radioactive waste is an important step to prepare waste for long-term storage or disposal and includes the following processes:▪ Immobilization which may or may not also provide volume reduction, includinga) Low temperature processes andb) Thermal processes;▪ Containerization fora) Transport,b) Storage, andc) Disposal;▪ Overpacking of primary containersa) Prior to disposal andb) In a disposal facility as part of disposal process.Conditioning consists of operations that produce a waste package suitable for handling, transportation, storage and/or disposal and may be performed for a variety of reasons including standardization of practices and/or wasteforms, technical requirements for waste stability in relation to a repository design or safety case, technical requirements related to waste transportation, societal preferences, regulatory preferences, etc. This paper gives an overview of recent advances in conditioning of low- and intermediate-level radioactive waste.The paper is based on the new IAEA Handbook “Conditioning of Low- and Intermediate-Level Liquid, Solidified and Solid Waste” which is one of eight IAEA handbooks intended to provide guidance for evaluating and implementing various characterisation and radioactive waste processing and storage technologies before final disposal
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Vnukov, V. S., B. G. Ryazanov y V. I. Sviridov. "Nuclear Safety of Disposal Facilities for Radioactive Waste Containing Fissile Nuclear Materials". Radioactive waste, n.º 3 (2019): 44–52. http://dx.doi.org/10.25283/2587-9707-2019-3-44-52.
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Ojovan, Michael I. y Zoran Drace. "Processing and Disposal of Radioactive Waste: Selection of Technical Solutions". MRS Proceedings 1518 (2012): 203–9. http://dx.doi.org/10.1557/opl.2012.1569.
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ABSTRACTAn overview of selection criteria for waste processing and disposal technologies is given. A systematic approach for selection of an optimal technology is proposed. Optimal selection of a technical processing and disposal option is case specific to the waste management needs. Waste streams considered are from nuclear applications, research, power generation, nuclear fuel cycle activities and decommissioning of nuclear facilities as well as for NORM-containing waste.
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Muller, Richard A., Stefan Finsterle, John Grimsich, Rod Baltzer, Elizabeth A. Muller, James W. Rector, Joe Payer y John Apps. "Disposal of High-Level Nuclear Waste in Deep Horizontal Drillholes". Energies 12, n.º 11 (29 de mayo de 2019): 2052. http://dx.doi.org/10.3390/en12112052.
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Spent nuclear fuel and high-level radioactive waste can be disposed in deep horizontal drillholes in sedimentary, metamorphic or igneous rocks. Horizontal drillhole disposal has safety, operational and economic benefits: the repository is deep in the brine-saturated zone far below aquifers in a reducing environment of formations that can be shown to have been isolated from the surface for exceedingly long times; its depth provides safety against inadvertent intrusion, earthquakes and near-surface perturbations; it can be placed close to the reactors and interim storage facilities, minimizing transportation; disposal costs per ton of waste can be kept substantially lower than for mined repositories by its smaller size, reduced infrastructure needs and staged implementation; and, if desired, the waste could be retrieved using “fishing” technology. In the proposed disposal concept, corrosion-resistant canisters containing unmodified fuel assemblies from commercial reactors would be placed end-to-end in up to 50 cm diameter horizontal drillholes, a configuration that reduces mechanical stresses and keeps the temperatures below the boiling point of the brine. Other high-level wastes, such as capsules containing 137Cs and 90Sr, can be disposed in small-diameter horizontal drillholes. We provide an overview of this novel disposal concept and its technology, discuss some of its safety aspects and compare it to mined repositories and the deep vertical borehole disposal concept.
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Devgun, J. S. "Suitability of unconsolidated sediments for hosting low-level radioactive waste disposal facilities". Canadian Journal of Civil Engineering 16, n.º 4 (1 de agosto de 1989): 560–67. http://dx.doi.org/10.1139/l89-086.
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Among the unconsolidated sediments, sand deposits are considered a rather unconventional geologic host medium for siting radioactive waste repositories, the clays being the preferred choice. A closer examination of the various geologic media, however, shows that in each case there are advantages and disadvantages. The key to safe and cost-effective disposal is to match the engineered design of the facility to the site's characteristics as well as the nature of the waste to be disposed of. In humid climates, free-draining sediments such as sand can provide the advantage of eliminating concern related to the “bathtub effect.”At Chalk River Nuclear Laboratories (CRNL), a sand dune has been proposed for hosting a low-level radioactive waste disposal facility. This paper discusses the suitability of unconsolidated sediments for radioactive waste disposal in general; in particular, it provides the rationalization for the selection of a sand dune as the host site at CRNL. Key words: radioactive waste, disposal facilities, unconsolidated sediments, site suitability, trench cover materials, sreismicity, soil liquefaction.
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Bugai, D. y R. Avila. "Scenarios and Pathways of Radionuclide Releases from Near-Surface Waste Disposal Facilities: A Brief Overview of Historical Evidence". Nuclear and Radiation Safety, n.º 3(87) (15 de septiembre de 2020): 21–27. http://dx.doi.org/10.32918/nrs.2020.3(87).03.
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The very low-level waste (VLLW) produced during decommissioning of nuclear facilities can be suitable for disposal in landfill type facilities. Considering the similarities in design, the experience gained in near-surface disposal of radioactive waste in trenches and vaults is relevant to the issue of VLLW disposal in landfills. This paper presents a brief review of internationally reported cases of radionuclide releases from near-surface disposal facilities. Based on this review, the conclusions are made that the following radionuclide release and exposure scenarios should be accounted for in safety assessment of VLLW disposal in landfills: i) leaching from waste to groundwater by atmospheric precipitations; ii) bath-tubing scenario; iii) scenarios caused by extreme meteorological and hydrological events (erosion, flooding, etc.); iv) human intrusion. The gaseous transport deserves attention for a number of relevant radionuclides, such as (C-14, Rn-222, etc.). In addition, the possibility of early degradation of engineered containment structures (soil covers, bottom seals) should be cautiously considered.
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Johnson, L. H. y L. O. Werme. "Materials Characteristics and Dissolution Behavior of Spent Nuclear Fuel". MRS Bulletin 19, n.º 12 (diciembre de 1994): 24–27. http://dx.doi.org/10.1557/s088376940004865x.
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The geologic disposal of spent nuclear fuel is currently under consideration in many countries. Most of this fuel is in the form of assemblies of zirconium-alloy-clad rods containing enriched (1–4% 235U) or natural (0.71% 235U) uranium oxide pellets. Approximately 135,000 Mg are presently in temporary storage facilities throughout the world in nations with commercial nuclear power stations.Safe geologic disposal of nuclear waste could be achieved using a combination of a natural barrier (the host rock of the repository) and engineered barriers, which would include a low-solubility waste form, long-lived containers, and clay- and cement-based barriers surrounding the waste containers and sealing the excavations.A requirement in evaluating the safety of disposal of nuclear waste is a knowledge of the kinetics and mechanism of dissolution of the waste form in groundwater and the solubility of the waste form constituents. In the case of spent nuclear fuel, this means developing an understanding of fuel microstructure, its impact on release of contained fission products, and the dissolution behavior of spent fuel and of UO2, the principal constituent of the fuel.
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Churakov, Sergey V., Wolfgang Hummel y Maria Marques Fernandes. "Fundamental Research on Radiochemistry of Geological Nuclear Waste Disposal". CHIMIA International Journal for Chemistry 74, n.º 12 (23 de diciembre de 2020): 1000–1009. http://dx.doi.org/10.2533/chimia.2020.1000.
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Currently, 5 · 1019 Bq of radioactive waste originating from the use of nuclear power for energy production, and medicine, industry and research, is maintained in Switzerland at intermediate storage facilities. Deep geological disposal of nuclear waste is considered as the most reliable and sustainable long-term solution worldwide. Alike the other European countries, the Swiss waste disposal concept embarks on the combination of engineered and geological barriers. The disposal cell is a complex geochemical system. The radionuclide mobility and consequently radiological impact depend not only on their chemical speciation but also on the background concentration of other stable nuclides and their behaviour in the natural environment. The safety assessment of the repository is thus a complex multidisciplinary problem requiring knowledge in chemical thermodynamics, structural chemistry, fluid dynamics, geo- and radiochemistry. Broad aspects of radionuclide thermodynamics and geochemistry are investigated in state-of-the-art radiochemical laboratories at the Paul Scherrer Institute. The research conducted over the last 30 years has resulted in a fundamental understanding of the radionuclides release, retention and transport mechanism in the repository system.
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Chen, Hai Ying, Chun Ming Zhang, Shao Wei Wang, Qiao Feng Liu y Jing Ru Han. "Discussion on Very Low-Level Radioactive Waste near Surface Disposal". Advanced Materials Research 807-809 (septiembre de 2013): 1207–10. http://dx.doi.org/10.4028/www.scientific.net/amr.807-809.1207.
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Radioactive waste disposal is one of the most sensitive environmental problems. As the arriving of decommissioning of early period nuclear facilities in China, large amounts of very low-level radioactive waste will be produced inevitably. The domestic and abroad definitions about very low-level radioactive waste and its disposal were introduced, and then siting principles of near surface disposal of very low-level radioactive waste were discussed. The near surface disposal sites’ natural barriers were analyzed from the crustal structure and the radionuclide adsorption characteristics of natural barriers. The near surface disposal sites’ engineering barriers were analyzed from the repository design and the repository barrier materials selection. Finally, the improving direction of very low-level radioactive waste disposal was proposed, which would promote the study of very low-level radioactive waste disposal in China.
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Watanabe, Yasutaka y Shingo Yokoyama. "Research on a long-term behavior of radioactive waste disposal facilities". Journal of the Atomic Energy Society of Japan 59, n.º 3 (2017): 142–46. http://dx.doi.org/10.3327/jaesjb.59.3_142.
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Klaß, Larissa, Philipp Ritz, Marius Hirsch, John Kettler, Andreas Havenith, Andreas Wilden y Giuseppe Modolo. "Gamma-spectrometric measurement procedure for a clearance concept of radioactively contaminated mercury from nuclear facilities". Journal of Radioanalytical and Nuclear Chemistry 329, n.º 2 (24 de junio de 2021): 565–80. http://dx.doi.org/10.1007/s10967-021-07840-7.
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AbstractRadioactive mercury waste constitutes a significant challenge, as no approved disposal concept yet exists for such waste in Germany. This work describes a decontamination and measurement procedure for a possible clearance of mercury from nuclear facilities and release into reuse or conventional hazardous waste disposal to reduce the amount of mercury in a nuclear repository. The measurement setup and procedure were developed and evaluated including Monte-Carlo N-Particle® Transport Code (MCNP® and Monte Carlo N-Particle® are registered trademarks owned by Los Alamos National Security, LLC, manager and operator of Los Alamos National Laboratory, (Werner 2018, Werner 2017)), simulations to ensure conservative assumptions during the measurements. Results from decontaminated mercury samples show that a clearance pursuant to the German regulations would be feasible.
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Tokarevskyi, O., K. Fuzik, S. Kondratiev y Z. Alekseeva. "Analysis of Safety Aspects of Disused Sealed Radiation Source Disposal". Nuclear and Radiation Safety, n.º 2(86) (12 de junio de 2020): 72–80. http://dx.doi.org/10.32918/nrs.2020.2(86).09.
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Sealed radiation sources (SRS) are extensively used worldwide in agriculture, industry, medicine and different research areas.
If further use of SRS is not envisaged, and the decision is made on declaration of these disused SRSs (DSRS) as radioactive waste (RW), then legislative and regulatory requirements for RW management are fully applicable from that point.
Since DSRSs have essential distinctions from other types of RW, in particular, high specific activity, it is critically important to ensure safe management of DSRS, declared as RW, at all stages of their management including disposal. DSRS disposal as RW is the final phase of SRS lifecycle and final stage of their safe and reliable management.
In this paper, there are considered safety issues for management of DSRS, declared as RW. Approaches to DSRS disposal recommended by IAEA, advantages and drawbacks of different disposal options for DSRS are analyzed.
DSRS disposal needs shall be considered taking into account safety requirements for RW disposal. First, DSRS shall be attributed to specific RW class to address respective disposal needs. This is a challenging issue because the approaches for categorization of SRS and classification of RW are essentially different.
DSRS declared as RW may be disposed of either together with other RW in the existing or planned RW disposal facilities, or in the disposal facilities designed and constructed specially for DSRS.
Current situation with DSRS management in Ukraine is analyzed. DSRS management strategy in Ukraine envisages their long-term storage in the centralized facility for 50 years with subsequent transfer for disposal. At that, there are neither specified disposal facilities where DSRS will be disposed of, nor established generic waste acceptance criteria for DSRS disposal. Recommendations on further steps for solving challenging issues related to safe disposal of DSRS in Ukraine are provided.
Solution of a set of challenging issues related to DSRS management revealed in the paper will promote implementation of comprehensive approach to safe disposal of DSRS in Ukraine.
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Bobrov, Aleksandr F., S. M. Kiselev y V. U. Shcheblanov. "ASSESSMENT OF THE SAFETY CULTURE AT THE RADIOACTIVE WASTE AND SPENT NUCLEAR FUEL DISPOPSAL FACILITIES". Hygiene and sanitation 96, n.º 9 (27 de marzo de 2019): 888–92. http://dx.doi.org/10.18821/0016-9900-2017-96-9-888-892.
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The paper deals with the quantitative assessment of the safety culture at facilities involved in the disposal of spent nuclear fuel and radioactive waste. Based on the method of the “internal” assessment of the safety culture, being developed in the A.I. Burnazyan Federal Medical Biophysical Centre, Moscow, 123182, Russian Federation, the comprehensive evaluation of the safety culture has been carried out with respect to the personnel of the following facilities: the Northwest Center for Radioactive Waste Management - SevRAO (NWC SevRAO) and the Far Eastern Center for Radioactive Waste Management- DalRAO (FEC DalRAO), which are subsidiaries of the RosRAO Enterprise.
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Finch, Robert J. y Nicholas Smith. "Reducing Safeguards Accounting and Verification Efforts on Retained Wastes". MRS Advances 5, n.º 5-6 (2020): 207–11. http://dx.doi.org/10.1557/adv.2020.102.
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ABSTRACTThe global expansion of nuclear energy will generate increasing quantities of waste with low levels of plutonium or other nuclear materials (NM) potentially subject to International Atomic Energy Agency (IAEA) safeguards. Reducing requirements on retained wastes has the potential to reduce future demands on already strained IAEA resources. We describe an effort to help the IAEA and Member States better estimate projected waste loads and associated safeguards obligations by developing a reporting tool to estimate types and sizes of future waste-storage and -disposal facilities. States can use such information to plan waste facilities, including size and type. The IAEA can use these data for inclusion in multiple agency reports and products for the benefit of Member States.
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Liu, Richeng, Sha Lou y Yujing Jiang. "Recent Advances in Fluid Flow in Fractured Porous Media". Processes 7, n.º 5 (2 de mayo de 2019): 255. http://dx.doi.org/10.3390/pr7050255.
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The fluid flows through both the fractures and pores in deep-seated rock masses, which is of special importance for the performance of underground facilities such as groundwater use and nuclear waste disposal [...]
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Luan, Yun Xia, Zhi Hong Ma y Li Gang Pan. "Establishion of Radioactive Contamination Monitoring Network and Bioremediation of the Soil around the Nuclear Facilities in China". Advanced Materials Research 347-353 (octubre de 2011): 512–21. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.512.
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The nuclear facilities accelerated continuously with the rapid development of the nuclear industry for the increasing demand for energy in China. The nuclear facilities were widely distributed in coastal areas or remote mountainous areas. With the rapid development of the nuclear industry, nuclear fuel cycle system, such as uranium mining and milling, component manufacturing, transportation and disposal of spent fuel, radioactive waste disposal, also would be large-scale distributed, so it is no doubt that the environmental impact would become increasingly prominent and severe. Radionuclides contaminate the environment through the gas, liquid and solid around nuclear facilities, and in case of radioactive leakage, the contamination would affect the soil and public health through food chain. This article aims to establish a nationwide network of early warning detection of radioactivity, the formation of nuclear facilities, radioactive soil around the monitoring and early warning mechanisms, and regularly publish relevant monitoring information, and to study bioremediation of radioactive contaminated soil, to eliminate the public about nuclear discoloration fears and concerns, promote economic and social development , and to keep the nuclear facilities and nature in harmony through environmental protection.
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Ewing, R. C. y W. Lutze. "Materials Science of Radioactive Waste Forms". MRS Bulletin 19, n.º 12 (diciembre de 1994): 16–19. http://dx.doi.org/10.1557/s0883769400048636.
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The materials science of radioactive waste forms and containment materials has long been a subject of interest to the Materials Research Society. One of the earliest (and continuing) MRS symposia, the Scientific Basis for Nuclear Waste Management, has been held 18 times since 1978. This symposium rotates abroad every third year: Berlin in 1982, Stockholm in 1985, Berlin in 1988, Strasbourg in 1991, and Kyoto this past October. Nearly 170 papers were presented at the Kyoto meeting.Materials science issues for nuclear waste disposal are unique in their scale and consequences. The wastes include an extremely wide variety of materials: spent nuclear fuel from commercial and research reactors; high-level liquid waste produced at West Valley, New York, during the reprocessing of commercial spent nuclear fuel; high-level waste (HLW) generated by the nuclear weapons program; nearly pure plutonium from the dismantling of nuclear weapons; highly enriched uranium from weapons; low-level, medium-level, and mixed waste from laboratories and medical facilities; and, finally, mill tailings from uranium mines and the residues from chemical processing, such as the radium-bearing filtrate presently in storage at Fernald, Ohio, and Niagara Falls, New York. Some material can be simply stabilized and monitored in situ, as is done for most uranium mill tailings and residues, but other materials require retrieval, processing, immobilization, and permanent disposal. The volumes of material that will require handling, immobilization, and disposal are enormous. In the United States, much of the weapons program waste is stored in tanks at Hanford, Washington and Savannah River, South Carolina.
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Decamps, F. y L. Dujacquier. "Overview of European practices and facilities for waste management and disposal". Nuclear Engineering and Design 176, n.º 1-2 (noviembre de 1997): 1–7. http://dx.doi.org/10.1016/s0029-5493(96)01335-0.
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Robbins, Rebecca A. y Michael I. Ojovan. "Vitreous Materials for Nuclear Waste Immobilisation and IAEA Support Activities". MRS Advances 1, n.º 63-64 (2016): 4201–6. http://dx.doi.org/10.1557/adv.2017.209.
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ABSTRACTVitreous materials are the overwhelming world-wide choice for the immobilisation of HLW resulting from nuclear fuel reprocessing due to glass tolerance for the chemical elements found in the waste as well as its inherent stability and durability. Vitrification is a mature technology and has been used for high-level nuclear waste immobilization for more than 50 years. Borosilicate glass is the formulation of choice in most applications although other formulations are also used e.g. phosphate glasses are used to immobilize high level wastes in Russia. The excellent durability of vitrified radioactive waste ensures a high degree of environment protection. Waste vitrification gives high waste volume reduction along with simple and cheap disposal facilities. Although vitrification requires a high initial investment and then operational costs, the overall cost of vitrified radioactive waste is usually lower than alternative options when account is taken of transportation and disposal expenses. Glass has proven to be also a suitable matrix for intermediate and low-level radioactive wastes and is currently used to treat legacy waste in USA, and NPP operational waste in Russia and South Korea. This report is also outlining IAEA activities aiming to support utilisation of vitreous materials for nuclear waste immobilisation.
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Sucipta, Sucipta y Suhartono Suhartono. "DETERMINATION OF CONCRETE VAULT THICKNESS OF NEAR SURFACE DISPOSAL FOR RADIOACTIVE WASTE AT SERPONG NUCLEAR AREA". Jurnal Pengembangan Energi Nuklir 19, n.º 2 (7 de abril de 2018): 103. http://dx.doi.org/10.17146/jpen.2017.19.2.3624.
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In order to support and complement the radioactive waste management facilities in Indonesia, BATAN will build a demonstration disposal facility in Serpong Nuclear Area (SNA). Demonstration disposal that will be built is Near Surface Disposal (NSD) type. Engineered vault for NSD is reinforced concrete. The calculations for determining the thickness of NSD concrete vault is based on the conceptual design as the result of the placement optimization of demonstration disposal that takes into account the inventory of radioactive waste and environmental geology conditions of the site at Serpong Nuclear Area. The thickness of the vault in this paper is focused on its ability to withstand radiation from stored waste so that workers or people who are around the disposal facility is safe with maximum radiation dose limit rate of 0.3 μSv / h. The calculation is performed with the aid of MicroShield 7:02 and Rad Pro Calculator Version 3:26 software. From the calculation so that the dose rate at the outer surface of the vault to be 0.3 μSv / h, required walls made of concrete with a density of 2:35 g / cm3 is 62.8 cm thickness.
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Pieraccini, Michel y Sylvain Granger. "A nuclear owner/operator perspective on ways and means for joint programming on predisposal activities". EPJ Nuclear Sciences & Technologies 6 (2020): 20. http://dx.doi.org/10.1051/epjn/2019039.
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Nuclear decommissioning is a worldwide competitive market. It is also the main source of radioactive waste from the nuclear energy field. In order to reduce the waste volume it is necessary to sort the actual radioactive waste to be disposed of and to separate them from other materials that could be recycled. Since 2015, Electricité de France (EDF) has gathered the waste management and dismantling (WM&D) projects, the related competences and human resources in the WM&D field, in a dedicated directorate (DP2D) and a company group called Cyclife (including waste treatment facilities). Taking into account the experience gained by carrying out its own WM&D projects as well as contributing to international cooperation, EDF considers that integrating collaborative research and development (R&D) on pre-disposal and waste management could be carried out following four main objectives: (1) alignment of the application of regulatory frameworks through appropriate definition of criteria and rules for radioactive waste to enable sensible worldwide comparison of technics; (2) improvement of technical and organisational aspects of nuclear reactors decommissioning using a demonstrator facility to be in operation, at first for graphite reactors, by 2022; (3) development of new techniques to decontaminate/homogenize metallic materials through a dedicated recycling route. These technics will be implemented in a new treatment facility foreseen to be available by 2030; and (4) increased training of decommissioning operators with the help of new technologies. All these improvements are aiming, beyond technical and experimental aspects, at reducing environmental impacts of nuclear activities as well as preserving the radioactive disposal volumes, as they are considered by EDF as rare resources.
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Iarmosh, I. y Yu Olkhovyk. "Conceptual Model to Determine Maximum Activity of Radioactive Waste in Near-Surface Disposal Facilities". Nuclear and Radiation Safety, n.º 3(71) (15 de agosto de 2016): 61–64. http://dx.doi.org/10.32918/nrs.2016.3(71).11.
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For development of the management strategy for radioactive waste to be placed in near-surface disposal facilities (NSDF), it is necessary to justify long-term safety of such facilities. Use of mathematical modelling methods for long-term forecasts of radwaste radiation impacts and assessment of radiation risks from radionuclides migration can help to resolve this issue. The purpose of the research was to develop the conceptual model for determining the maximum activity of radwaste to be safely disposed in the NSDF and to test it in the case of Lot 3 Vector NSDF (Chornobyl exclusion zone). This paper describes an approach to the development of such a model. The conceptual model of 90Sr migration from Lot 3 through aeration zone and aquifer soils was developed. The results of modelling are shown. The proposals on further steps for the model improvement were developed.
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YOSHIDA, Yoshikazu. "Application of exemption principles to radioactive waste disposal and recycling of materials from nuclear facilities." Journal of the Atomic Energy Society of Japan / Atomic Energy Society of Japan 31, n.º 8 (1989): 894–99. http://dx.doi.org/10.3327/jaesj.31.894.
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Palmu, M., T. Eng y T. M. Beattie. "Towards an 'implementing geological disposal technology platform' in Europe". Mineralogical Magazine 76, n.º 8 (diciembre de 2012): 3439–44. http://dx.doi.org/10.1180/minmag.2012.076.8.57.
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AbstractSeveral European waste management organizations have started work on creating a technology platform to accelerate the implementation of deep geological disposal of radioactive waste in Europe. There is an increasing consensus in the international community about geological disposal as the preferred option for solving the long-term management of spent fuel, high-level waste and other longlived radioactive wastes. At the same time, European citizens have a widespread desire for a permanent solution for high-level radioactive waste disposal. A majority of European countries with nuclear power have active waste-management programmes, but the current status and the main challenges of those programmes vary. The most advanced waste management programmes in Europe (i.e. those in Sweden, Finland and France) are prepared to start the licensing process of deep geological disposal facilities within the next decade. Despite the differences between the timing and the challenges of the different programmes, there is a joint awareness that cooperation on the scientific, technical and social challenges related to geological disposal is needed, and that it is beneficial for the timely and safe implementation of the first geological disposal facilities. Such a demonstration of a viable solution for the management of high-level radioactive waste will enhance stakeholder confidence in Europe. It is envisaged that a technology platform would enhance European cooperation in this area. The platform will provide a tool for reducing overlapping work, to produce savings in total costs of research and implementation, and to make better use of existing competence and research infrastructures. From 2008, SKB (Sweden) and Posiva (Finland) led the preparation work to set up the implementing geological disposal of radioactive waste technology platform (IGD-TP). Since then other implementers from France, Germany, Switzerland, United Kingdom, Spain and Belgium have joined the project. To date a strategic research agenda for the platform has been prepared and consulted upon, which is now the basis for taking the platform into a deployment phase.
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Olkhovyk, Yu A. "Perspective Schemes of Conditioning of Liquid Radioactive Waste of Ukrainian Nuclear Power Plants". Nuclear Power and the Environment 18 (2020): 48–56. http://dx.doi.org/10.31717/2311-8253.20.3.6.
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The existing world experience of practical use of sorption technology and technology of cementing liquid borne radioactive waste of nuclear power plants (NPP) with water-water energetic reactors (WWER) to obtain a product 1suitable for transfer to disposal facilities is considered. It has been concluded that salt cake accumulated in NPP storage facilities is a major problem that determines the further choice of the development and implementation of conditioning technologies. Currently, 18,000 salt cake containers stored at the Zaporizhzhia NPP and Khmelnitskiy NPP storage facilities have exceeded their design life. A possible solution is to change the classification of the salt cake and to classify it as solid radioactive waste. It is noted that the existing tax system for the generation of radioactive waste in Ukraine does not contribute to the choice of conditioning technologies aimed at minimizing the volume of the final product. The prospect of application of the technology of melting in the “cold crucible” for one-stage formation from a evaporator bottoms and salt cake borosilicate glass, guaranteed capable in the conditions of surface disposal to ensure the isolation of radionuclides during the time required for decay to a safe level of radioactivity. It is proposed to create a melting unit according to the modular scheme, when several parallel crucibles with capacity up to 20 kg/h with cheaper highfrequency generators with a capacity of 160 kW are connected to common ventilation system. The urgency of carrying out technical and economic analysis to determine the optimal 56 ISSN 2311-8253 Nuclear Power and the Environment № 3 (18) 2020 solutions for the introduction of effective and economically sound technologies for the processing of evaporator bottoms and salt cake at Ukrainian NPPs is emphasized.
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KAWAMURA, Hideki. "Construction Technologies of Underground Radioactive Waste Disposal Facilities―A Way forward to Passive Safety". Journal of the Atomic Energy Society of Japan 51, n.º 6 (2009): 484–89. http://dx.doi.org/10.3327/jaesjb.51.6_484.
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Toran, Laura y Virginia Cohen-Bradley. "Evaluation of Hydrogeo-chemical Conditions for Development of Nuclear Criticality in Low-Level Waste Disposal Facilities". Groundwater Monitoring & Remediation 20, n.º 3 (agosto de 2000): 58–67. http://dx.doi.org/10.1111/j.1745-6592.2000.tb00276.x.
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Yim, Man-Sung y Scott A. Simonson. "Performance assessment models for low level radioactive waste disposal facilities: A review". Progress in Nuclear Energy 36, n.º 1 (enero de 2000): 1–38. http://dx.doi.org/10.1016/s0149-1970(99)00015-3.
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Pankratov, Nikolai S. y Vyacheslav V. Belov. "Selection of sites for the construction of radioactive waste disposal points". RUDN Journal of Engineering Researches 21, n.º 1 (15 de diciembre de 2020): 36–47. http://dx.doi.org/10.22363/2312-8143-2020-21-1-36-47.
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The article deals with the selection of sites for the construction of nuclear installations, radioactive waste disposal sites and other facilities for the use of nuclear energy. The review of modern approaches to the selection of sites for placement of near-surface radioactive waste disposal points shows that the system research in this area is not fully presented, and is mainly aimed at solving problems of an engineering-geological nature for the location area, as well as the choice of materials for engineering protection barriers. In this paper, using the example of radioactive waste disposal sites, we review the requirements set by the regulatory documents of the Russian Federation and the International Atomic Energy Agency in the field of site selection. The authors proposed additions to the methodology for selecting sites for the construction of low-and medium-level waste disposal sites based on the system and GIS analysis of the ALARA principles, as well as the method of weighted evaluation of criteria and their pairwise comparisons. The multi-criteria nature of the site selection problem is proposed to be described by GIS analysis of data with drawing the corresponding limiting and preferred requirements directly on the map of the area, which is shown in the article by the example of selecting sites for radioactive waste disposal points. Taking into account the necessary requirements at various stages of the life cycle, as well as their significance, can be assessed by weighted estimates and pairwise comparisons, followed by their introduction into the GIS analysis. This approach allows to choose rational options for placing potential sites, taking into account the life cycle of the object, in a rational way, with compliance with all necessary regulatory requirements.
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Babich, Sergey A. "Nuclear Materials Ownership in the Russian Federation". Energy law forum 4 (14 de enero de 2021): 99–104. http://dx.doi.org/10.18572/2410-4396-2020-4-99-104.
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In response to the challenges of the epoch, “nuclear” laws currently regulate safety issues related to handling of nuclear materials, nuclear facilities operation, related transactions, nuclear waste processing and disposal, state control over the nuclear energy use, and international cooperation in the nuclear sphere. One of the most important institutions of the “nuclear” regulation system in Russian law is the institution of ownership of nuclear materials, understood by the modern legislator as materials containing, or capable of reproducing, fissile (fissionable) nuclear substances. Consolidating the rules of nuclear materials ownership, the legislator further formulates requirements for nuclear materials control and accounting, transactions procedure, and safe operation of nuclear facilities, as well as introduces liability for violation of such requirements. Today, many aspects related to the legal status of nuclear materials owners and the notion of handling nuclear materials deserve a deep legal analysis, since the current legal regulation has gaps and contradictions. The legal writing method used to word such norms, structures, and basic notions must meet the criteria of clarity, unambiguous interpretation, and absence of regulatory gaps, that is why the system of legal regulation of the institution of nuclear materials ownership needs further improvement.
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Babich, Sergey A. "NUCLEAR MATERIALS OWNERSHIP IN THE RUSSIAN FEDERATION". Energy law forum 4 (14 de enero de 2021): 40–47. http://dx.doi.org/10.18572/2312-4350-2020-4-40-47.
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In response to the challenges of the epoch, “nuclear” laws currently regulate safety issues related to handling of nuclear materials, nuclear facilities operation, related transactions, nuclear waste processing and disposal, state control over the nuclear energy use, and international cooperation in the nuclear sphere. One of the most important institutions of the “nuclear” regulation system in Russian law is the institution of ownership of nuclear materials, understood by the modern legislator as materials containing, or capable of reproducing, fissile (fissionable) nuclear substances. Consolidating the rules of nuclear materials ownership, the legislator further formulates requirements for nuclear materials control and accounting, transactions procedure, and safe operation of nuclear facilities, as well as introduces liability for violation of such requirements. Today, many aspects related to the legal status of nuclear materials owners and the notion of handling nuclear materials deserve a deep legal analysis, since the current legal regulation has gaps and contradictions. The legal writing method used to word such norms, structures, and basic notions must meet the criteria of clarity, unambiguous interpretation, and absence of regulatory gaps, that is why the system of legal regulation of the institution of nuclear materials ownership needs further improvement.
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Large, J. H. "Decommissioning of Nuclear Reactor Systems". Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 206, n.º 4 (noviembre de 1992): 273–80. http://dx.doi.org/10.1243/pime_proc_1992_206_044_02.
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The decision-making process involving the decommissioning of the British graphite-moderated, gas-cooled Magnox power stations is complex. There are timing, engineering, waste disposal, cost and lost generation capacity factors and the ultimate uptake of radiation dose to consider and, bearing on all of these, the overall decision of when and how to proceed with decommissioning may be heavily weighed by political and public tolerance dimensions. These factors and dimensions are briefly reviewed with reference to the ageing Magnox nuclear power stations, of which Berkeley and Hunterston A are now closed down and undergoing the first stages of decommissioning and Trawsfynydd, although still considered as available capacity, has had both reactors closed down since February 1991 and is awaiting substantiation and acceptance of a revised reactor pressure vessel safety case. Although the other first-generation Magnox power stations at Hinkley Point, Bradwell, Dungeness and Sizewell are operational, it is most doubtful that these stations will be. able to eke out a generating function for much longer. It is concluded that the British nuclear industry has adopted a policy of deferred decommissioning, that is delaying the process of complete dismantlement of the radioactive components and assemblies for at least one hundred years following close-down of the plant. In following this option the nuclear industry has expressed considerable confidence that the decommissioning technology required will he developed with passing time, that acceptable radioactive waste disposal methods and facilities will be available and that the eventual costs of decommissioning will not escalate without restraint.
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Reheim, N. A. Abdel, M. Abdel Geleel, Ashraf A. Mohammed, E. R. Atta, Emtithal A. Elsawy y Amaal Tawfik. "Investigation of novel composites to be used as backfill materials in radioactive waste disposal facilities". Journal of Radioanalytical and Nuclear Chemistry 322, n.º 2 (16 de octubre de 2019): 455–65. http://dx.doi.org/10.1007/s10967-019-06809-x.
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Junker, D. "Nuklearmedizin – Personalbelastung und Aktivitätsabgaben". Nuklearmedizin 30, n.º 04 (1991): 141–48. http://dx.doi.org/10.1055/s-0038-1629566.
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The Nuclear Medicine Division and 30 other groups at the University of Hannover School of Medicine are taken as examples to describe the diagnostic, therapeutic and research uses of radioactivity and the effectiveness of the associated radiation protection. The evolution of radiation exposures of 520 employees followed over the last six years and the methods used for the disposal of radioactive waste are explained. The adaptation of protective measures to individual and, in particular, specific working conditions has led to approximately 90% of all exposures remaining under the detection limit of the personal dosimeters during the entire observation period. Only a few people contributed to the collective radiation dose. In 1990, the average annual dose equivalent among personnel in the Nuclear Medicine Division was 0.12 mSv/person. By the installation of facilities for the storage of isotopes with short half-lives and of filters in the air circulation system, environmental contamination could be held much below the legal limits. Combustible and liquid waste containing radionuclides with long half-lives such as tritium and 14C had to be disposed of separately. However, they were a small fraction of the total radioactivity used.
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Banford, H. M., R. D. Scott, I. Robertson y T. McCool. "The decommissioning of the nuclear research reactor and associated facilities at the Scottish Universities Research and Reactor Centre". Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 219, n.º 1 (1 de febrero de 2005): 15–26. http://dx.doi.org/10.1243/095440805x7026.
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The decommissioning of a 300 kW Argonaut type universities research reactor and associated facilities has been completed at the Scottish Universities Research and Reactor Centre. The strategy adopted for the demolition of the reactor and its ancillary plant and buildings is discussed. One of the principal areas of the work was the effort expended on the determination of the radioisotope abundance of the reactor structure and thereby its impact on the characterization of waste for disposal and the radiation dose budget for personnel. Extensive use was made of remotely operated vehicles to minimize this dose.
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Hutchinson, Harry. "More Weight on the Job". Mechanical Engineering 132, n.º 07 (1 de julio de 2010): 36–38. http://dx.doi.org/10.1115/1.2010-jul-4.
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This article discusses that new methods and heavier equipment are expected to hasten the nuclear waste transfer at the Hanford Site’s tank farms. The site includes old processing plants, groundwater that exceeds safe levels of radioactivity, and high-level radioactive waste held in 149 aging tanks—some more than 60 years old—that lie underground just 10 miles from the Columbia River. The objective is to remove the highly radioactive waste from the old tanks, which have a single shell construction, and transfer it to 28 newer, more-secure double-shell tanks nearby, where the waste will safely reside until it can be treated in facilities now under construction. There are approximately 53,000,000 gallons of nuclear and chemical waste stored in the tanks at the Hanford Site. Bechtel National Inc., another of the prime contractors for Office of River Protection, is building a treatment plant that will process the wastes being stored in the underground tanks into a stable glass form for permanent disposal in a federal geological repository.
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Chapman, N. A. y G. M. Williams. "Hazardous and radioactive waste management: a case of dual standards?" Geological Society, London, Engineering Geology Special Publications 4, n.º 1 (1987): 489–94. http://dx.doi.org/10.1144/gsl.eng.1987.004.01.59.
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AbstractThe recent activity by the UK Nuclear industry to investigate the safety of sites in shallow ground for the disposal of low level radioactive wastes has not surprisingly prompted comparison with landfill facilities in which toxic wastes are being deposited. The conclusion is that the level of site investigation, operation and long term performance assessment proposed for the radwaste sites is many orders of magnitude greater than that required by the regulatory authorities for landfills where the operators responsibility for the safety of the site virtually disappears once the last load of waste is tipped and the disposal licence lapses. Furthermore, the research budget for radwaste exceeds that for landfill disposal by a similar amount even though the risk from radwaste can be shown to be many times less than that from toxic wastes. Since the same government department is in charge of radwaste and landfill disposal, it seems that dual standards are operating, and that either the radwaste managers are being singled out for unfair scrutiny, or that insufficient attention is being directed at the real threat to the environment from 'antediluvian and ramshackle' landfill practices.
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Labied, S., T. El ghailassi, A. Bouih, L. Moutei, Y. Benbrahim, T. Guedira y O. Benali. "Study of the effect of Kaolin in the mortar of cement matrices by confinement of ion exchange resins". MATEC Web of Conferences 149 (2018): 01056. http://dx.doi.org/10.1051/matecconf/201814901056.
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Radioactive waste arising as a result of nuclear activities should be safely managed from its generation to final disposal in an appropriate conditioned form to reduce the risk of radiation exposure of technical personnel and of the public and to limit contamination of the environment. The immobilization of low and intermediate level radioactive wastes in cementitious matrices is the most commonly used technique to produce inexpensive waste matrix that complies with regulatory requirements in order to protect humans and the environment against nuisance caused by ionizing radiation. Cement based materials are used in radioactive waste management to produce stable waste forms. This matrix constitutes the first build engineering barrier in disposal facilities. In this work, the kaolin is used to enhance the mechanical performance of the matrix of confinement of ion exchange resins by gradually replacing the sand in mortar with kaolin clay. The Kaolin clay sample was a special pure product, sourced from a foreign country. The maximum quantity of resins that can be incorporated into the mortar formulation without the packages losing their strength is 13.915% which results in a better mechanical strength at 6.7686 MPA compression with kaolin.
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Paunov, Petar y Ivaylo Naydenov. "Long-Term Radiotoxicity Evaluation of PWR Spent Uranium and MOX Fuel and Highly Active Waste". E3S Web of Conferences 207 (2020): 01024. http://dx.doi.org/10.1051/e3sconf/202020701024.
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One of the main concerns related to nuclear power production is the generation and accumulation of spent nuclear fuel. Currently most of the spent fuel is stored in interim storage facilities awaiting final disposal or reprocessing. The spent fuel is stored in isolation from the environment in protected facilities or specially designed containers. Nevertheless, spent fuel and highly active waste might get in the environment in case the protective barriers are compromised. In such a case, spent fuel may pose risk to the environment and human health. Those risks depend on the concentration of the given radionuclide and are measured by the value of potential danger. The potential danger is called also ’radiotoxicity’. The paper examines spent uranium and MOX fuels from a reference PWR, as well as the highly radioactive wastes of their reprocessing. The radiotoxicity of the four materials is examined and evaluated for a cooling time of 1000 years. The contribution of different radionuclides is assessed and the cases of reprocessing and no reprocessing of spent fuel have been compared.
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Kronberg, Magnus, Jan Gugala y Keijo Haapala. "State-of-the-art and proof-of-concept installations for repository concepts based in crystalline rock". Mineralogical Magazine 79, n.º 6 (noviembre de 2015): 1665–73. http://dx.doi.org/10.1180/minmag.2015.079.6.43.
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AbstractOver the last five decades private and national energy programmes worldwide have been producing a variety of radioactive wastes. One of the safest ways of disposing of this waste is to bury it deep underground in purpose-built geological disposal facilities. Currently, there is no operating geological repository in Europe for high-level waste but the goal of the IGD-TP is that the first repository shall be fully operational before the year 2025. Several studies and experiments are ongoing at various potential repository sites in Europe with the goal to establish general approaches that can be adapted for any country in need of a geological repository.The Swedish Nuclear Fuel and Waste Management Co (SKB) in Sweden and Posiva Oy in Finland are developing a method for geological disposal of high-level long-lived nuclear waste in crystalline rock, the KBS-3 method. KBS-3V (vertical) is both organizations reference design, but KBS-3H (horizontal) emplacement is also being researched as a potential alternative. Of high importance in the development is demonstrating the technical feasibilityin situof safe and reliable construction, manufacturing, disposal and sealing of such geological disposal facilities. Parts of these demonstrations are carried out under the framework of EurAtom/FP7 and one of these projects is the LUCOEX project where SKB is demonstrating horizontal emplacement, the Multi Purpose Test (MPT), and Posiva is demonstrating vertical buffer installation processes.The MPT includes the key components of the horizontal design and comprises all essential steps; manufacturing of the full-scale components, their assembly, installation in the drift and monitoring of the early buffer evolution. The MPT installation was successfully performed in late 2013. By combining the components, an initial verification of the design implementation has been achieved. At the same time, integrating the components has meant the recognition of some design weaknesses and the design will be updated accordingly.Posiva's KBS-3V buffer installation equipment that places buffer blocks with high precision in vertical deposition holes is currently being developed and will be tested during 2014 and 2015 in real underground conditions. The machine uses vacuum lifting tools for moving the buffer blocks and laser scanning technology to position both the machine and blocks. Functionality of the concept and equipment selected will be confirmed by the tests and the installation tests will provide important information about the suitability of the selected buffer dimensions and tolerances.
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VARI, ANNA y ZOLTAN FERENCZ. "RADIOACTIVE WASTE MANAGEMENT IN HUNGARY: CHANGING APPROACHES AND CONFLICTS". Journal of Environmental Assessment Policy and Management 09, n.º 02 (junio de 2007): 185–209. http://dx.doi.org/10.1142/s1464333207002767.
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One of the most interesting paradoxes of the application of nuclear energy in Hungary is that although the building, operation, and even the recent lifetime extension of the Paks nuclear power plant has not faced significant social opposition, attempts for siting radioactive waste disposal facilities have been accompanied by a number of social conflicts. The paper reviews the history of radioactive waste management in Hungary from the 1970s until recently. It is found that since the political transition of 1990, top-down technocratic approaches to facility siting have been replaced by the so-called "market approach", which put a strong emphasis on host community support. Most important elements of the latter approach include public information and the provision of generous financial compensation/incentives for host and neighbouring communities. However, analysis of recent Hungarian siting cases shows the weaknesses of the pure market approach, e.g., the lack of transparency and openness regarding national strategies, the lack of accountability, and the focus on financial incentives rather than sustainable development issues.
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Takiguchi, Katsuki. "Special Issue on Structural Engineering of Nuclear Related Facilities". Journal of Disaster Research 5, n.º 4 (1 de agosto de 2010): 339. http://dx.doi.org/10.20965/jdr.2010.p0339.
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Since it was first used, nuclear energy’s control has been an important issue. With the generation of electricity as a major nuclear energy application, the improvement of nuclear power generation technology has been required by society, including power plant design, construction, and maintenance and radioactive waste disposal. Nuclear facilities must also take into account disaster prevention, as in the case of earthquakes and terrorist attacks, particularly because of the extensive potential and actual range of effects. This has made nuclear energy issues important considerations in JDR editorial meetings. In the July 16, 2007, case of the Niigataken Chuetsu-oki Earthquake, quake ground motion equaled or exceeded that presumed in the design of the Tokyo Electric Power Company’s Kashiwazaki-Kariwa Nuclear Power Station, the world’s largest nuclear power station. Specific safety objectives for nuclear power plants include stopping the nuclear reaction, cooling the nuclear reactor, preventing radioactive material emission, and shielding surroundings from radiation - all of which were almost completely achieved in this case. Many problems were also revealed, however. JDR examined a special issue on Kashiwazaki-Kariwa Nuclear Power Station earthquake resistance at an editorial meeting but determined that such a topic remains premature. In its stead, we have planned a number featuring the structural engineering of nuclear related facilities as a first step in a series of special issues on nuclear energy. The papers for this number were submitted mainly by the presenters of 20th International Conference on Structural Mechanics in Reactor Technology, held in Espoo, Finland, in 2009 with the catch phrase “Challenges Facing Nuclear Renaissance.” We greatly appreciate the many contributions to this issue, and would like to thank the reviewers, without whose cooperation this number could not have been published. Please note that, independent of special numbers such as this one, JDR looks forward to receiving papers on a wide range of fields related to disaster.
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Tokarevsky, O. y I. Iarmosh. "Assessing Impact of Sorption in Geological Medium on Permissible Activity of Radioactive Waste in Near-Surface Disposal Facilities". Nuclear and Radiation Safety, n.º 3(75) (22 de agosto de 2017): 34–39. http://dx.doi.org/10.32918/nrs.2017.3(75).06.
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The paper considers the conservative scenario of potential exposure that envisages simultaneous destruction of barriers with simultaneous release of radionuclides by the example of Lot 3 near-surface radioactive waste disposal facility at the Vektor Industrial Complex located in the Chornobyl Exclusion Zone. A conceptual model that considers migration of radionuclides through the aeration zone and aquifer to the potable water well, as well as mixing of infiltration water containing radionuclides with ground water in case of reaching the aquifer, was developed to analyze the mentioned scenario. Permissible specific activity of radioactive waste in the facility is calculated under the assumption that radioactive waste contains only 90Sr radionuclide. Normalysa software is used for calculations.
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Al-Hadhrami, Ahmed y Andrew B. Lawson. "Bayesian hierarchical modeling of latent period switching in small-area putative health hazard studies". Statistical Methods in Medical Research 20, n.º 1 (26 de agosto de 2010): 5–28. http://dx.doi.org/10.1177/0962280210374256.
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In recent years, small area risk assessment modelling and data analysis around putative hazard sources has become a fundamental part of public health and environmental sciences. In this study, we address a fundamental problem in the analysis of such data, when intermittent operation of facilities could lead to evidence for latent periods of risk. This study examines the development of Bayesian models for the latent switching operating period of putative hazard sources such as nuclear processing plants and waste disposal incinerators. The developed methodology is applied in a simulation study as well as to a real data example.
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Liang, Suu-Yan, Wen-Sheng Lin, Chan-Po Chen, Chen-Wuing Liu y Chihhao Fan. "A Review of Geochemical Modeling for the Performance Assessment of Radioactive Waste Disposal in a Subsurface System". Applied Sciences 11, n.º 13 (24 de junio de 2021): 5879. http://dx.doi.org/10.3390/app11135879.
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Radionuclides are inorganic substances, and the solubility of inorganic substances is a major factor affecting the disposal of radioactive waste and the release of concentrations of radionuclides. The degree of solubility determines whether a nuclide source migrates to the far field of a radioactive waste disposal site. Therefore, the most effective method for retarding radionuclide migration is to reduce the radionuclide solubility in the aqueous geochemical environment of subsurface systems. In order to assess the performance of disposal facilities, thermodynamic data regarding nuclides in water–rock systems and minerals in geochemical environments are required; the results obtained from the analysis of these data can provide a strong scientific basis for maintaining safety performance to support nuclear waste management. The pH, Eh and time ranges in the environments of disposal sites cannot be controlled, in contrast to those under experimental conditions in laboratories. Using a hypothetical error mechanism for the safety assessment of disposal sites may engender incorrect assessment results. Studies have focused on radionuclide reactions in waste disposal, and have offered evidence suggesting that these reactions are mainly affected by the geochemical environment. However, studies have not examined the thermodynamics of chemical reactions or interactions between water and minerals, such as the surface complexation and adsorption of various nuclide-ion species. Simple coefficient models have usually been applied in order to obtain empirical formulas for deriving Kd to describe nuclide distributions in the solid or liquid phase in water–rock geochemical systems. Accordingly, this study reviewed previous research on the applications of geochemical models, including studies on the development of geochemical models, sources of thermodynamic databases (TDBs) and their applications in programs, the determination of the adequacy of TDBs in surface complexation models and case studies, and the selection and application of activity coefficient equations in geochemical models. In addition, the study conducted case studies and comparisons of the activity coefficients derived by different geochemical models. Three activity coefficient equations, namely the Davies, modified Debye–Hückel, and Pitzer equations, and four geochemical models, namely PHREEQC, MINEQL+, MINTEQA2, and EQ3/6, were used in the study. The results demonstrated that when the solution’s ionic strength was <0.5 m, the differences in the activity coefficients between the Davies and modified Debye–Hückel equations were <5%. The difference between the Pitzer and Davies equations, or between the Pitzer and modified Debye–Hückel equations in terms of the calculated activity coefficients was <8%. The effect of temperature on the activity coefficient slightly influenced the modeling outputs of the Davies and modified Debye–Hückel equations. In the future, the probability distribution and uncertainty of parameters of Kd and the equilibrium constant can be used in geochemical and reactive transport models to simulate the long-term safety of nuclear waste disposal sites. The findings of this study can provide a strong scientific basis for conducting safety assessments of nuclear waste disposal repositories and developing environmental management or remediation schemes to control sites marred by near-surface contamination.
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Batyaev, V. F., M. D. Karetnikov y S. V. Sklyarov. "Active Neutron Monitoring of Nuclear Fuel Cycle Fissile Materials". EPJ Web of Conferences 225 (2020): 06011. http://dx.doi.org/10.1051/epjconf/202022506011.
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A decommissioning of nuclear fuel cycle facilities is inseparable from the problems of radioactive waste disposal. One of these problems is the categorization of a waste according to the content of beta- and alpha-emitters. Beta-emitters can be identified by existing technologies; however, the trouble arises when detecting alpha-emitting elements, primarily the long-lived members of the actinium chain with the specific activity of kBq/kg when they are spread inside a structural material. The report considers an application of an active neutron method-a differential die-away technology for reliable control of small quantities of FM. The essence of this method consists in sounding the interrogated item by pulsed thermal neutrons and recording the induced fission neutrons. The ratio of the number of fission neutrons to the number of source neutrons gives the normalized number of fission neutrons that is linked to the FM mass in the interrogated object. The work presents the scheme and principle of operation of an experimental device, as well as the results of measurement of concrete structures that contain internal traces of fissile materials. Analysis of the results shows that the proposed method allows the detection of ~ 6 mg of fissile material per kg of concrete with possible localization (cartogram) of the contaminated area.
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Beer, Hans-Frieder. "Radioactive waste management at the Paul Scherrer Institute, the largest Swiss national research centre". Nuclear Technology and Radiation Protection 24, n.º 3 (2009): 212–18. http://dx.doi.org/10.2298/ntrp0903212b.
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This paper presents the current radioactive waste management practices at the Paul Scherrer Institute (PSI). The PSI contributes to waste related problems in two aspects, namely to the scientific basis of waste management and disposal, and to the practical treatment and storage of radioactive waste. In addition to the tasks of treating on-site generated waste, PSI manages the wastes from medicine, industry, and research throughout Switzerland on behalf of the government. Therefore the Dismantling and Waste Management Section is a part of the Logistics Department at PSI. Proved and accepted methods have to be developed for the safe conditioning and storage of radioactive waste. Various waste treatment facilities exist at PSI. The conditioning facility is dedicated to sorting, compaction by a 120 t press, solidification with special cement, and embedding in concrete. Specialized facilities were constructed for waste from the decommissioning of research reactors. Activated aluminum and its alloys were melted in crucibles and embedded in concrete in a concrete container. After dismantling the structural material of the reactors, it was embedded in concrete in the same manner. For the conditioning of activated reactor graphite, a dedicated method was developed. Graphite was crushed to replace sand in the grout, for embedding radioactive waste in concrete containers. For accelerator waste, a walk-in hot cell equipped with an electrically driven manipulator is available where the highly activated large components (targets, beam dump) can be cut into pieces and embedded in concrete in containers. To guarantee the fulfillment of the demands of the regulators, the Dismantling and Waste Management Section applies an accredited quality management system for the safe collection, conditioning, and storage of radioactive waste.
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Richardson, J. A. "United States high-level radioactive waste management programme: Current status and plans". Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 211, n.º 5 (1 de agosto de 1997): 381–92. http://dx.doi.org/10.1243/0957650971537286.
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Commercial reactor nuclear power generation in the United States is produced by 107 units and, during 1996, represented over 21 per cent of the nation's electricity generation in 34 of the 50 states and, through electric power wheeling, between states in most of the 48 contiguous states. Spent fuel is stored in fuel pools at 70 sites around the country and the projected rate of spent fuel production indicates that the current pool storage will be exceeded in the out years of 2000, 2010 and 2020 at 40, 67 and 69 of these sites respectively. The total accumulation projected by the end of 1996 at reactor sites is 33 700 metric tons of heavy metal (MTHM), with projections for increasing accumulations at annual rates of between 1800 and 2000 to produce an end of life for all commercial nuclear reactors of about 86 000 MTHM. There are presently eight facilities in six states with out-of-pool dry storage amounting to 1010 MTHM and this dry storage demand will increase. Based on all current commercial reactors achieving their 40 year licensed operation lifetimes, the dry storage needs will increase to 3128 MTHM at 28 sites and 20 states by 2000 and 11 307 MTHM at 58 sites in 32 states by 2010; the year 2010 is the present scheduled operation date for the federal mined geological disposal repository being characterized by the USDOE at Yucca Mountain, Nevada. The enabling statute for the federal high-level radioactive waste management programme is the 1982 Nuclear Waste Policy Act (NWPA) which charges the USDOE with the responsibility for the disposal of HLW and spent nuclear fuel. The Act also charges the utilities with the responsibility for managing their spent nuclear fuel until the USDOE can accept it into the federal waste management system. The funding for the federal programme is also stipulated by the Act with the creation of the Nuclear Waste Fund, through which the electric utilities entered into contract with the USDOE by payment of a fee of 1 mill per kilowatt hour sold and for which the USDOE would start collection of spent fuel from the reactor sites starting 31 January 1998.
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Metcalf, P. y D. Louvat. "International safety standards and supporting projects related to demonstrating the safety of radioactive waste disposal facilities". Radioprotection 44, n.º 5 (2009): 519–24. http://dx.doi.org/10.1051/radiopro/20095096.
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Stefanovic, Nebojsa, Natasa Danilovic-Hristic y Bosko Josimovic. "The spatial and urban planning concerns related to nuclear facilities locations: Case study of the Vinca Institute location". Nuclear Technology and Radiation Protection 32, n.º 1 (2017): 99–108. http://dx.doi.org/10.2298/ntrp1701099s.
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The spatial and urban planning is one of the key instruments for the planned formation and development of locations for nuclear facilities, especially in terms of meeting the strict spatial conditionality, as well as in terms of the formation of protection zones in their surroundings. This paper systemizes the international criteria and requirements for the locations of nuclear facilities and analyses the spatial distribution of nuclear facilities in the surrounding countries of the Republic of Serbia. The research was conducted on the example of the location of the Vinca Institute of Nuclear Sciences, within which the fulfilment of spatial requirements, treatment of the location in the existing spatial and urban plans and relationship between other functions in the surrounding area were analysed. The paper proves the starting hypothesis that the general requirements related to both the spatial development of nuclear facilities locations and the protection from radiation have not been met in the Vinca location and its surroundings. It was determined that the spatial and urban plans encompassing the area of Vinca do not contain sufficiently specific planning solutions and that, as such, they do not provide a sufficient planning basis for meeting the necessary requirements and obligations regarding the protection from radiation. The paper also gives recommendations for further spatial development and protection of the Vinca location and its surroundings. The research condcted in this paper indicates the importance and priority of further research so that the necessary planning solutions for further development of the complex in Vinca and for the formation of protection zones could be defined through creating a new planning documentation. In addition, the paper particularly highlights the need for conducting a research to identify a location for permanent disposal of radioactive waste. It also indicates the necessity of considering the aspects of environmental protection and protection from radiation in the national and international context.