Top PDF Disposal of High-Level Nuclear Waste in Deep Horizontal Drillholes

Disposal of High-Level Nuclear Waste in Deep Horizontal Drillholes

Disposal of High-Level Nuclear Waste in Deep Horizontal Drillholes

Abstract: Spent nuclear fuel and high-level radioactive waste can be disposed in deep horizontal 14.. drillholes in sedimentary, metamorphic, or igneous rocks.[r]

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Radionuclide migration in plutonic rocks: implications for high level nuclear waste disposal

Radionuclide migration in plutonic rocks: implications for high level nuclear waste disposal

Chapter 8: Simulation of Repository Processes II: The Interaction of Granite and Synroc doped with Mixed Fission Products 8.1 Introduction - Previous Work 8.2 Mixed Fission Products.. 8.[r]

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Radionuclide migration in plutonic rocks: implications for high level nuclear waste disposal

Radionuclide migration in plutonic rocks: implications for high level nuclear waste disposal

8.5 Conclusions The leach testing in deionised water of the Coles Bay Granite, Roxby Downs Granite and the Kambalda Granodiorite with Synroc doped with the mixed fission products under s[r]

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Radionuclide migration in plutonic rocks: implications for high level nuclear waste disposal

Radionuclide migration in plutonic rocks: implications for high level nuclear waste disposal

Interaction between the migrating ground waters and the rock has been influeneed by the presence offracture-infilling and other secondary minerals, As an analogue for the behaviour of th[r]

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Radionuclide migration in plutonic rocks: implications for high level nuclear waste disposal

Radionuclide migration in plutonic rocks: implications for high level nuclear waste disposal

Interaction between the migrating ground waters and the rock has been influeneed by the presence offracture·infilling and other secondary minerals, As an analogue for the behaviour o'f t[r]

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Canada's High-Level Nuclear Waste Disposal Concept: The Evaluation Process and a Review of Some Aspects of the Research Work

Canada's High-Level Nuclear Waste Disposal Concept: The Evaluation Process and a Review of Some Aspects of the Research Work

OCflce SAT - Subsurface Advisory Team (Environment Canada.) SRG - Scientific Review Group (FEARO) TAC - Technical AdvIsory Committee (AECI.) Figure 1: Evaluation of Canadian Nuclear Wast[r]

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High Level Nuclear Waste Repository Thermal Loading Analysis

High Level Nuclear Waste Repository Thermal Loading Analysis

Siting a second high level nuclear waste repository presents a considerable challenge due to the high economic, social, and political costs associated with the siting of a repository. The application of an alternative fuel cycle, such as the Advanced Fuel Cycle Initiative (AFCI), could serve to minimize the volume of SNF waste required for disposal in a geologic repository, as well as to remove the high heat radioisotopes from SNF to maximize the amount of waste that can be emplaced per unit area in the repository, therefore minimizing the repository footprint. For example, utilizing a full recycle nuclear waste management policy, as depicted in Figure 5-1, could serve to mitigate the need for a second repository, though the Yucca Mountain statutory limit would be required to be increased. 36 Thus it is recommended that additional research into alternative waste management strategies in conjunction with research into the area expansion of the Yucca Mountain repository footprint be performed.
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The Corrosion of Carbon Steel under Deep Geologic Nuclear Waste Disposal Conditions

The Corrosion of Carbon Steel under Deep Geologic Nuclear Waste Disposal Conditions

Iron is an allotropic metal which, depending on temperature, can exist in at least three different structures [11, 12]. Figure 1-7 shows that as liquid Fe metal is cooled it first forms a solid body- centered cubic (BCC) δ-phase, known as delta ferrite, followed by a face-centered cubic (FCC) γ- phase, known as austenite, before finally reverting back to a BCC structure, designated the α- phase. The α-phase, also known as ferrite, can exist in both a non-magnetic and a magnetic form above and below 768 °C, respectively. While the magnetic properties change at this temperature, the Fe structure remains unchanged based on X-ray studies [11]. At increased pressures, a third allotrope (ε-Fe) of hexagonal close-packed (HCP) structure is possible, Figure 1-8 [12]. The alloying elements within the steel, most importantly the C content, will determine the point at which these structural changes occur. Fe alloys are classified as either steels (<2.14 wt% C) or cast irons (>2.14 wt% C) [11]. The equilibrium phase diagram for the Fe-C system showing these distinctions is given in Figure 1-9. Carbon steel, or mild steel, is a Fe-C alloy with low levels of impurities such as Mn, S and Si, where C atoms are located interstitially within the octahedral holes of the BCC structure of the α-Fe [12]. Carbon steels can be classified into three major categories: low, medium, and high-carbon steel based on an increasing C content. Low- carbon steels are generally classified by a C content of less than 0.25% and are the most widely produced [13].
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The effect of organic retarders on grout thickening and setting during deep borehole disposal of high-level radioactive waste

The effect of organic retarders on grout thickening and setting during deep borehole disposal of high-level radioactive waste

Advantages associated with safety, cost, and ease of imple- mentation, and the ability to drill deeper larger diameter holes (Juhlin and Sandstedt, 1989; Beswick, 2008; Beswick and Forrest, 1982; Exxon Neftegas; Sakhalin-, 2013), means that the use of deep boreholes to dispose of high level radioactive wastes (HLW, including spent nuclear fuel (SF)) is now being increasingly seen as a viable alternative to emplacement in geologically shallow, mined repositories (Chapman and Gibb, 2003; Beswick et al., 2014). The disposal of wastes generated during the production of nuclear en- ergy is of significant importance to the overall nuclear fuel cycle and is currently receiving particular attention around the world. Even though considerable research has been performed in devel- oping waste repositories several hundreds of meters below ground, there is currently no operational facility to provide ultimate waste disposal. Therefore, the development of an alternative more ad- vantageous concept for the disposal of HLW is of particular interest to those involved in the nuclear fuel cycle.
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Characterisation of a high pH cement backfill for the geological disposal of nuclear waste : the Nirex Reference Vault Backfill

Characterisation of a high pH cement backfill for the geological disposal of nuclear waste : the Nirex Reference Vault Backfill

patent (Francis et al., 1997), and subsequently, several assessments of various aspects of this material (e.g. mineralogy, strength, or porosity, as described below), there has not been a comprehensive character- isation of NRVB, where all tests are performed on a consistent batch. Additionally, some of the raw materials used in early development of NRVB are no longer available due to changes in the powder suppliers (Radioactive Waste Management, 2016), therefore, materials to be used when a GDF is in operation may differ in composition and other key characteristics. It is important to understand how the chemical and physical properties of the back fi ll raw materials may a ff ect the short- and long-term performance of the backfill, to support development of GDF engineering and post-closure safety assessment. We here present a literature review of the published data on NRVB, even where datasets are incomplete, or details pertinent to the analysis of the data are ab- sent.
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Bio safety Knowledge, Waste Disposal Practices and
Identification of Parasites in Biomedical Wastes from
Healthcare Establishments in Lagos and Abuja, Nigeria

Bio safety Knowledge, Waste Disposal Practices and Identification of Parasites in Biomedical Wastes from Healthcare Establishments in Lagos and Abuja, Nigeria

Urine and stool waste samples were collected respectively from holding points in selected HCEs located in Lagos. The samples comprised of 56% stool and 44% urine samples. Fresh stool and urine samples were collected using clean universal sample bottles with tight fitting lids. After collection, the samples were transported in ice-pack to the laboratory for examination. Urine samples were transported to the laboratory and the samples maintained in a deep freezer at temperature of about -20oC before examination. Each sample bottle was labeled for type, age, sex and date of collection. The sample tube was half-filled and saline solution added. Centrifugation was carried out at 2000rpm for 2mins. The supernatant was decanted and sedi- ment was examined with 5% lugol iodine not to miss the tro- phozoites of Entamoeba and Giardia. Stool samples were vis- ually examined under the microscope to note the consistency, presence of abnormal features, whether they are watery, bloody or mucous. Stool samples were later processed through formol ether concentration techniques as described by Garcia [5] the observations from formol ether concentration technique were used for analyses.
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Analysis of the quality of environmental disclosures made by Australian resources sector companies

Analysis of the quality of environmental disclosures made by Australian resources sector companies

In this project, decision-usefulness theory was considered applicable based on the assumption that companies would not supply environmental disclosures of high quality if such disclosures were not deemed to be important in the decision-making process of users. A number of limitations have been acknowledged in some of the decision-usefulness studies (Chan and Milne, 1999; Rikhardsson and Holm, 2008; Reimsbach and Hahn, 2015) in relation to research design and method. For example, given the experimental setting of these studies, where students are used as a proxy for investors, the conclusions would be based on an over-simplified version of the decision-making process (Reimsbach and Hahn, 2013). Further, as Connelly et al. (2011, p. 54) indicated, users may not find sustainability related information useful if they do not know what to look for. In other words, why does that information need to be considered in decision-making? Therefore, it is suggested that simply giving out a list of information and asking users to choose from a set of possible decisions, based on the supplied information, does not adequately allow users to make an informed decision. Instead, it is imperative to provide the context in which the supplied information is produced and its possible implications in order to obtain more meaningful insights from the decision-makers. Therefore, in this project, a survey of investors was conducted, designed to seek their perceptions of the quality of a number of environmental disclosures within different contexts. The underlying assumption is that if investors deem such disclosures as useful, companies are expected to signal them via annual and/or sustainability reports. Therefore, decision-usefulness theory was deemed appropriate in this project in explaining the quality of environmental disclosures.
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Proposal for a Council Directive amending Directive 75/442/EEC on waste. Proposal for a Council Directive on hazardous waste. COM (88) 391 final, 5 August 1988

Proposal for a Council Directive amending Directive 75/442/EEC on waste. Proposal for a Council Directive on hazardous waste. COM (88) 391 final, 5 August 1988

- 2 - Whereas the tommission•s proposal takes as a base a high level of environmental protection with as much regard to the definition as to the disposal of hazardous waste; Whereas it i[r]

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The Community's research and development programme on radioactive waste management and storage  Shared cost action Annual progress report 1986

The Community's research and development programme on radioactive waste management and storage Shared cost action Annual progress report 1986

Progress of work and obtained results State of advancement The test disposal of high-level radioactive waste canisters in the Asse salt mine will be performed with a view to the planning[r]

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Waste Recycling: Utilization of canteen(kitchen) waste and garden waste in vermicomposting

Waste Recycling: Utilization of canteen(kitchen) waste and garden waste in vermicomposting

After the composting period the moisture content ,pH ,Electric conductivity, temperature P,K,Ca,Mg find out. The test carried out by using oven, pH meter, and electric conductivity meter temperature directly measure by using thermometer and nutrients find out by using photo-flame meter. Each treatment was carried out in triplication. Site selected for vermicomposting near to the jawahar education society and the waste collected from the jawahar education society like garden trimmed waste which is passing through the 25mm diameter. Canteen waste collected from the canteen waste in which waste food and waste water collected, and paper waste. Before sampling, the eventual leachate captured in a stainless bowl was returned to the vermicomposted material to achieve a closed loop. A sample of 200 g from every bowl was collected every month for 45,55,65,75 days. The earthworms were then sorted out and the resulting samples were dried at laboratory temperature and ground.
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THE FACTORS THAT AFFECTING ON SOLID WASTE GENERATION IN ZALINGY TOWN – CENTRAL DARFUR STATE – SUDAN 2015

THE FACTORS THAT AFFECTING ON SOLID WASTE GENERATION IN ZALINGY TOWN – CENTRAL DARFUR STATE – SUDAN 2015

Lack of advanced technology, facility for separation at source, strength of solid waste management policy and enforcement, environmental education and awareness and income status of individuals among others, are factors affecting solid waste scenario.(Abel 2009) showed that education, income and social status are important factors influencing per capita solid waste generation. . Age, location, occupation and amount charged for waste collection are determinant factors for using public waste collection services in Ibadan (Ajani, 2007). The quantity and categories of solid waste generation also varies with socio-economic groups in which the high and middle groups take the lion share (Sridhar et al., 1985).
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Assessment of Waste Management Practices among Residents of Owerri Municipal Imo State Nigeria

Assessment of Waste Management Practices among Residents of Owerri Municipal Imo State Nigeria

There are various methods of waste disposal including: land filling: which involves burying the waste in abandoned or unused quarries, mining voids or burrow pits and covering it with layers of soil; incineration: in- volves subjection of solid organic wastes to combustion at a very high temperature of about 10,000 so as to convert them into residue or gaseous products; open dumping: whereby dumping can be done on open land or sea; composting: this is an aerobic, biological process of degradation of biodegradable organic matter; hog feeding: this involves feeding animals like pigs with left over materials of waste; mechanical destructor: this in- volves the use of machines to destroy waste materials [3]. Recycling of waste which means taking waste mate- rials and transforming them into raw products, results in saving natural resources, saving energy, reducing dis- posal costs, reducing harmful emission to air and water, saving money and creating jobs [4].
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Dissolution of UK high-level waste glass under simulated hyperalkaline conditions of a colocated geological disposal facility

Dissolution of UK high-level waste glass under simulated hyperalkaline conditions of a colocated geological disposal facility

duration of the experiment; thus, it is not thermody- namically favorable for Si to be released into solution. Accordingly, the main process likely to occur during this regime is the incorporation of Ca onto the hydrated glass surface (Eqn. 5), thus the dissolution is still in the initial “incubation” regime. The low surface- area-to-volume ratio results in fewer sites for Ca incor- poration compared with high surface-area-to-volume ratios; thus, the Ca concentration becomes constant at high concentrations (680 mg/L, compared with 65 10 mg/L for high SA/V), inhibiting dissolution of Si and formation of C-S-H phases. This may explain why Mercado-Depierre et al. 11 did not observe an incu- bation regime in their dissolution of glass in Ca-rich solution – a SA/V ratio of 20 000/m was utilized, such that Ca removal from solution occurred rapidly due to the higher number of accommodating surface sites, and thus, Ca–Si “quasi”-equilibrium was attained on more rapid timescales. It may be hypothesized that should this low surface-area-to-volume ratio system be given more time to react the same dissolution processes as observed for high surface-area-to-volume ratios may occur.
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Assessment of the impact of selected changes in the deep geological repository model on its long-term safety

Assessment of the impact of selected changes in the deep geological repository model on its long-term safety

To evaluate the long-term safety of the deep geological repository, a model of the disposal system, geosphere and the initial model of the reference biosphere has been developed. Using the GoldSim simulation tool, the annual effective dose for individuals of different ages from critical exposure group was calculated. Within the analysis, the impact of changes in distribution coefficients for different soil types and relevant translocation factors expressing the rate of contaminant transition into environmental compartments was investigated, when ingestion is considered to the dominant exposure pathway. From the results we can see, that the properties of the first achieved part of the biosphere have a significant influence on the dose value. Subsequent changes in other contaminant spreading parameters have a negligible effect on the overall dose. The maximum dose value is in all cases lower than the recommended limit set by the ICRP. In all considered cases, same radionuclides affect annual effective dose. In the last years of the analysis the increase in dose is due to the contribution of specific radionuclides. Pb-210 accumulates in the soil at a later time of the analysis and from there passes into the plant leaves. The maximum far field dose from Ra-226 increases because of the greater amount of uranium in spent fuel. Ra-226 migrates appreciably from the repository system only as a result of the migration of Th-230, which is not at a high enough concentration to be solubility limited.
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waste minimization

waste minimization

On-site recycling Off-site recycling disposal disposal source source waste No waste minimisation With waste minimisation, recycling and treatment to treatment waste... Preferred hi[r]

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