Nuclear Waste Disposal

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Probabilistic modelling of calcium leaching in a tunnel for nuclear waste disposal

Probabilistic modelling of calcium leaching in a tunnel for nuclear waste disposal

Deep nuclear waste disposal facilities need to be studied over periods of one or more order of magnitude greater than those of classical civil engineering. This leads to consider some degradation phenomena that are most of the time not taken into account because of their slow kinetics. This is the case with calcium leaching for concrete structures exposed to water from the host rock in a deep underground disposal. Moreover, civil engineering constructions are naturally subjected to variability, from many origins: their dimensions, their construction processes, their exposure to several loadings... Among these variables, which influence the behaviour of the structure and, thus, its lifespan, some of them introduce a variability on the material characteristics, evolving with time and not necessary homogeneous in the whole structure, whereas some others create a variability on the loading itself, which the structure is subjected to.
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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

While electrochemical monitoring of steel coupons exposed to simulated groundwater solutions may provide some insight into the corrosion behaviour of steel waste containers (Chapters 4 and 5), there are limitations to the length of such experiments. As such, the experiments described in this chapter were designed to follow the corrosion process over an extended period of time, up to 30 months. The experiments were designed to mimic the conditions expected in a DGR environment, although the bentonite backfill material was not included. Experiments were conducted under anaerobic conditions in solutions which varied in [Cl - ] and pH and in a simulated groundwater solution for exposure periods up to 30 months. Specimens were exposed to an initial period of air exposure prior to emplacement in the solutions to simulate the initial state of the container when first emplaced. Samples removed from experiments were analyzed using techniques such as Raman spectroscopy, FTIR spectroscopy, scanning electron microscopy and focused ion beam milling.
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Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal

Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal

The presence of nitrates in the vicinity of waste packages may result in oxidising conditions favourable to the mobility of a series of radionuclides (Se, U, Tc, Pu, Np...)[7]. However, in the anoxic conditions prevailing in the cell, different phenomenon of redox reactions could lead to nitrates reduction and thus to reducing conditions favourable to the storage safety. Reduction of nitrate (NO 3 - ) may occur from surface catalysis provided by the different type of steels present in the

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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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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

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

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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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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Household medical waste disposal policy in Israel

Household medical waste disposal policy in Israel

hospitals, in the mail office and even in big supermar- kets. Additionally, enacting laws to allow organization to hold drug collection events, similar to the DEA collec- tion events held in the US, or collection of household medical waste from people's homes. (b) Individuals who pass away in retirement homes leave medications that are usually thrown to the garbage. It is important to es- tablish a mechanism to collect and transfer the non- expired medications to needy populations [41] and the expired ones to destruction. (c) It is worthy to examine laws for incentives for returning medications to HMO or private pharmacies, such as getting pay-back money or other rewards. (d) Similarly to Europe, it is advisable to promote regulations and procedures regarding special instructions and precautions for disposal that will appear on the outer packaging of medicinal product, in the pa- tient information leaflet or on the medication label. (e) Laws that will regulate the funding of programs for col- lection and destruction of medications, preferably fol- lowing the “polluters pays” principle, by which, pharmaceutical companies will pay for the collection, shipment and destruction of household medical waste.
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Optimal ways of disposal of highly radioactive waste

Optimal ways of disposal of highly radioactive waste

The fact is that the uncertainties respecting long-term isolation of the waste in crystalline rock using presently proposed repository concepts are very significant and that more reliable engineered barriers are required. The most important barrier that comes in focus is the canister. Steel canisters will have a negative chemical impact on smectitic clay buffer and do not qualify as well as those of copper. The iron/copper canister has weaknesses, however, primarily by the risk of failure by the very high swelling pressure exerted on it in combination with ten- sion caused by the upward expanding buffer around the upper part of the canister. An ideal solution would be to use the HIPOW type of copper canisters, which are pre- pared by high-temperature compaction of copper powder with spent fuel distributed in it. The technique has been tested on nearly full scale and it has been shown that the porosity of such copper is in fact lower than that of cast copper metal (Figure 12). Further refinement is required for implementation but the creators see this technique of preparing copper canisters as feasible [11].
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Oceanography related to deep sea waste disposal

Oceanography related to deep sea waste disposal

Detailed heat flow determinations Heat transfer experiments Long term soil mechanics experiment Detailed studies of local seismicity Small scale seismic profiling Detailed acoustic and s[r]

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Geological disposal of nuclear waste: A primer

Geological disposal of nuclear waste: A primer

levels of radioactivity for hundreds of thousands of years, geological disposal has been preferred from the outset. The first thoughtful scientific review by Earth scientists of what would be required was by John Bredehoeft and colleagues in 1978. This prescient paper recognized the importance of different waste types, the challenges of site characterization, the perturbations that the emplaced waste would impose on geological formations, and the time frames over which geological isolation would be required. Many ingenious, alternative ways of disposing of some, or all, of the nuclear waste inventory have been proposed, but geological disposal remains the only one that appears to offer safe, long-term disposal of all waste types. The report by the UK s Committee on Radi oactive Waste Management (CoRWM 2006) provides a comprehensive analysis of alternatives. Nuclear nations in western Europe and elsewhere had also begun to plan for geological disposal during the late 1970s and 1980s. Most countries have interacted through the International Atomic Energy Authority, which has established safety requirements for the disposal of radioactive waste (IAEA 2011a) and guidance on how geological disposal facilities should be developed (IAEA 2011b). A history of ten national programs was published recently by the Nuclear Waste Technical Review Board (2015) and, in part, is summarized in the article by Metlay (2016 this issue).
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Finnish Concept for Spent Nuclear Fuel Disposal

Finnish Concept for Spent Nuclear Fuel Disposal

The repository and its operation are designed in accordance with existing legislation and regulatory guides concerning the use of nuclear energy. An access tunnel and three shafts with lifts provide access routes to the surface. Apart from the underground rooms for disposal operation, such as disposal tunnels and deposition holes in the disposal panels, central tunnels and auxiliary and technical rooms in the controlled and uncontrolled area will be provided. The repository will be enlarged in stages as disposal progresses. The access tunnel is mainly used for the transfer of large material flows, such as blasted rock, backfill material and building materials. The repository and the encapsulation plant will be constructed in 2010s.
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DISPOSAL OF FOOD WASTE AT SOURCE-AN INNOVATIVE APPROACH

DISPOSAL OF FOOD WASTE AT SOURCE-AN INNOVATIVE APPROACH

Generally 70% waste produced in kitchen is biodegradable 7% plastics 10% combustible items and 3% inerts Accordingly the quantity of waste generated per household is 0.5 kg /day. It was thought to make equipment for a single house, but it may not be an economical solution, therefore we decided to make such equipment which can take care of 40-50 residences. Peoples are not interested to put their hands in waste even it is generated by themselves, showing the need to make the equipment user-friendly and atomized. In India the common practice in most of the cities is to throw the waste behind compound wall or to store it beside roads which creates unhygienic situations as it is spread by the domestic animals showing the need to dispose it off safely The report of the committee to “Evolve road map on
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Rock alteration in alkaline cement waters over 15 years and its relevance to the geological disposal of nuclear waste

Rock alteration in alkaline cement waters over 15 years and its relevance to the geological disposal of nuclear waste

The secondary solid phases produced during high pH rock alter- ation may affect radionuclide migration through the CDZ by chang- ing the sorption properties of the material. A key radionuclide of concern is U(VI) which is highly mobile and hazardous over the long timescales relevant to geological disposal (NDA, 2010c). As C–S–H has been found to be the predominant secondary phase pro- duced by high pH rock alteration and is also the most abundant phase in hardened cement paste (Taylor, 1990), which is used as an ILW wasteform, the interaction of U(VI) with these phases has been studied in some detail (Harfouche et al., 2006; Tits et al., 2011; Gaona et al., 2012; Atkins and Glasser, 1992). However, few experimental studies have looked at the interaction of U(VI) with secondary phases in-situ following high pH mineral/rock alteration and these have generally been limited to investigation after only several months of high pH reaction (e.g. Berry et al., 1999). Continued evolution of altered material over decades may further change surface properties and so affect U(VI) interactions. Therefore experimental investigation of these interactions with rock after extended periods of alteration could help fill this knowledge gap.
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Rock alteration in alkaline cement waters over 15 years and its relevance to the geological disposal of nuclear waste

Rock alteration in alkaline cement waters over 15 years and its relevance to the geological disposal of nuclear waste

The interaction of groundwater with cement in a geological disposal facility (GDF) for intermediate level radioactive waste will produce a high pH leachate plume. Such a plume may alter the physical and chem- ical properties of the GDF host rock. However, the geochemical and mineralogical processes which may occur in such systems over timescales relevant for geological disposal remain unclear. This study has extended the timescale for laboratory experiments and shown that, after 15 years two distinct phases of reaction may occur during alteration of a dolomite-rich rock at high pH. In these experiments the dis- solution of primary silicate minerals and the formation of secondary calcium silicate hydrate (C–S–H) phases containing varying amounts of aluminium and potassium (C–(A)–(K)–S–H) during the early stages of reaction (up to 15 months) have been superseded as the systems have evolved. After 15 years signif- icant dedolomitisation (MgCa(CO 3 ) 2 + 2OH ? Mg(OH) 2 + CaCO 3 + CO 3(aq) 2 ) has led to the formation of
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Regulated Waste Disposal Manual. Texas Tech University Health Sciences Center Regulated Waste Disposal Manual

Regulated Waste Disposal Manual. Texas Tech University Health Sciences Center Regulated Waste Disposal Manual

Procedure All special/infectious lab waste can be disposed of by incineration or by steam disinfection (refer to Appendix 2). Place all waste including sharps containers into biohazardous drums with red plastic liners. Make sure the liners are tied and lids are closed for weekly pickup by housekeeping personnel. Bio-Medical waste tubs may not exceed 50 pounds in weight. Problems with waste pick up should be directed to the Environmental Safety Manager in Safety Services.

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How to develop a waste management and disposal strategy

How to develop a waste management and disposal strategy

The return of products to the original manufacturer ‘product takeback’ to be disassembled is an important element of reverse logistics. Examples of this include the takeback of Kodak’s disposable camera; Canon’s toner cartridges and Xerox’s photocopy machines [12] Another example of recycling is that of ‘waste exchange’ where the firm producing the waste, who would normally have to pay to have it disposed of, sells or gives it away to another organisation, which subsequently uses it in their own production processes. Waste management, minimisation, energy efficiency, source reduction and waste exchange can be grouped under the heading of ‘eco-efficiency’. Eco-efficiency is a catch-all term that appears to have been adopted to express the application of the ‘produce more from less’ or ‘use less resources to produce the same amount’ philosophies. The UK Government’s Advisory
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Solid waste generation and disposal by Hotels in Coimbatore City

Solid waste generation and disposal by Hotels in Coimbatore City

It is inferred from Table 6 that the independent variables included in the model for all five zones in Coimbatore city have accounted for more than 50 per cent variation in the quantum of solid waste generated by the sample hotels. In East Zone, the co-efficient of multiple determinations R 2 indicates 58.31 per cent variations in quantity of solid waste generated by the hotels. Among the independent variables, the variable namely the number of customers per day was statistically significant at 5 per cent level. It means that with one per cent increase in this variable, solid waste could be generated by 0.3817 per cent. The other variables namely number of tables and number of employees were found to be insignificant. In the case of West Zone, all the independent variables included in the regression model jointly accounted for 65.10 per cent variation in the quantum of solid waste generated. Among the variables, the variable namely the number of customers per day and number of employees were found to be statistically significant. It indicates that an addition of one percentage to this variable could affect 0.3363 and 0.1210 per cent increase in quantum of solid waste generation.
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ELECTRONIC WASTE CONSCIOUSNESS AND PREVAILING DISPOSAL PRACTICES IN INDIA

ELECTRONIC WASTE CONSCIOUSNESS AND PREVAILING DISPOSAL PRACTICES IN INDIA

The main sources of electronic waste in India are the government, public and private (industrial) sectors, which account for almost 70 per cent of total waste generation. The contribution of individual households is relatively small at about 15 per cent; the rest being contributed by manufacturers. Though individual households are not large contributors to waste generated by computers, they consume large quantities of consumer durables and are, therefore, potential creators of waste. An Indian market Research Bureau (IMRB) survey of „E-waste generation at Source‟ in 2009 found that out of the total e-waste volume in India, televisions and desktops including servers comprised 68 per cent and 27 per cent respectively. Imports and mobile phones comprised of 2 per cent and 1 per cent respectively.
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