Disposal of the UK's legacy nuclear waste is the biggest challenge facing the industry at present. There is currently no long term storage facility in the UK and the inventory is continually growing. This project investigates the role that digital geoscientific data collection, analysis and modelling techniques play in the search for, and development of, a Geological Disposal Facility (GDF), critically analyses classical techniques and new, digital methodologies to assess what their impact would be on any site investigation. The Borrowdale Volcanic Group outcrop in Cumbria, NW England was chosen as it provides an analogue to a higher-strength crystalline basement setting for a GDF. Terrestrial lidar and photogrammetric surveys were conducted at four locations around the study area. These provided information on the fracture geostatistics which are the main fluid migration pathways in the subsurface in the BVG. The mechanics of deformation are identified by analysing the clustering of data points via digital stereonet analysis. The analysis shows the rocks sampled are highly fractured and their orientations and dips reflected the extensional tectonism experienced in the area. These are in the form of adjacent sets trending broadly NNE-SSW and NNW-SSE at very high angler dips (~70 degrees). A new workflow developed for this work demonstrates how a potential site's fracture statistics, and indeed the 3D geology, should be investigated as part of future GDF site investigations. Areas of complex geology such as the BVG present many difficulties in interpretation and analysis due to the poorly constrained polyphase nature of the deformation. These complexities make characterisation and modelling highly problematic, and as such, areas of simpler geology should be investigated first. Assessments which were based on early geological studies using traditional field data collection techniques underestimated the impact of heterogeneity on fluid flow migration modelling within the subsurface. This suggests that, should a GDF should be developed in such a geological setting, huge difficulties may be encountered. These will be associated with the development of performance assessments and safety cases which are typically based on geological models that should use such complex data. In addition to this, datasets collected using digital methods are a powerful visualisation tools for communication of complex geology, that can be utilised in stakeholder engagement activities that will form a key part of any GDF development process.

Neste trabalho, vidros contendo um resíduo industrial denominado lama vermelha, foram desenvolvidos e caracterizados. Foi utilizada a quantidade mínima de 60% em massa de lama vermelha na produção dos vidros para promover a utilização desse resíduo. De acordo com os resultados de difração de raios X obtidos, observa-se que é possível produzir materiais a partir da lama vermelha com fases amorfas consideráveis, embora fases cristalinas referentes ao Fe originário do resíduo estejam presentes. O material denominado 60L40S, o qual possui 60% em massa de lama vermelha na sua composição nominal, apresentou as melhores propriedades dentre as composições estudadas, porém apresentou também alta temperatura de fusão. Ajustes na composição desse material foram realizados buscando diminuir essa temperatura. Os resultados mostram que os ajustes foram satisfatórios no desempenho de diminuir a temperatura de fusão, porém perdas na propriedade química desse material foram observadas. Elementos comumente encontrados na composição química de rejeitos nucleares foram adicionados aos vidros produzidos neste trabalho visando estudar os efeitos dessa adição nas propriedades químicas e térmicas desses materiais. Foi observado que é possível adicionar até 15% em massa de elementos simuladores aos materiais produzidos e essa adição promove a diminuição da temperatura de fusão. Acima de 15% em massa os elementos adicionados se precipitam na estrutura do material. Foi observado que, embora haja perdas na durabilidade química do material 60L40S após a adição dos elementos simuladores, esse material, quando em contato com água, mantém os elementos simuladores confinados em sua estrutura. Esse resultado é promissor, pois sugere que o material 60L40S é capaz de imobilizar em sua estrutura elementos provenientes de rejeitos nucleares. / Glasses based on red mud, a residual material from bauxite processing, were developed and characterized in this work. In order to promote its use, a minimum 60 wt% of red mud was used in the production of the glasses. According to XRD results, materials containing considerable amorphous phases were produced when using red mud as raw material. These amorphous phases were observed even though crystalline phases associated to Fe coming from the red mud itself were present. The material denominated 60L40S, which has a nominal composition of 60 wt% red mud showed the best properties comparing with the others compositions studied. However, these materials presented a high melting temperature. Changes in the composition of this material were made with the objective of lowering this temperature. Results indicated that the changes made to the material were successful in the reduction of the melting temperature. However, a reduction in the chemical properties of the resulting material was observed. Elements usually found in the chemical composition of nuclear wastes were added to the glasses produced. It was done with the objective of determining the effect of these elements on the chemical and physical properties of the red mud based glasses obtained. It was found that it was possible to add up to 15 wt% of these elements to the materials produced. The addition of these simulants materials promoted a reduction in the melting temperature of the resulting material. Above 15 wt%, the added elements precipitate in the structure of the resulting material. Even though the reduction in the chemical durability of the 60L40S material when simulant elements were added, it was observed that this material contained the simulant elements confined in its structure when in contact with water. This is a promising result, since it indicates that the 60L40S has the potential to immobilize elements from nuclear wastes.

The aim of diploma thesis is to analyse the overall technical base and to monitor logistic processes which are from the very beginning associated with radioactive waste and spent nuclear fuel. The main emphasis is put on spent nuclear fuel from nuclear power plants. The current situation in this area is illustrated by an example of the Czech Republic and Sweden. The comparison of Czech and Swedish system leads to demonstration of strengths and weaknesses of the used methods.

Nuclear law in the Czech Republic Abstract Nuclear law can be defined as a set of legal rules designed to regulate legal or natural persons engaged in activities related to fissile materials, ionizing radiation, and radiation from natural sources of radiation, with the aim of ensuring the protection of persons, property, and the environment. The topic of the thesis Nuclear law in the Czech Republic is the legal regulation of peaceful use of nuclear energy and ionizing radiation in the context of Czech legislation within the framework of public law, including its links and connections to the legal regulation of this issue at the international (European, global) level. After a brief introduction of nuclear law and its basic terminology, the thesis presents in a comprehensive summary the legal regulation at the international, European and national level, together with the legal principles that are manifested within the legal norms of nuclear law. Within the framework of the Czech legal framework, the main focus is on Act No. 263/2016 Coll., the Atomic Act, and its relation to individual areas of nuclear law. In terms of institutional arrangements for the administration of the use of nuclear energy in the Czech Republic, the institutions with significant competencies within the framework of nuclear law are...

The Nuclear Waste Fund constitutes a financial system that finances future costs of the management of spent nuclear fuel as well as decommissioning of nuclear power plants. The fund invests its capital under strict rules which are stipulated in the investment policy established by the board. The policy stipulates that the fund can only invest according to certain allocation limits, and restricts it to invest solely in nominal and inflation-linked bonds issued by the Swedish state as well as treasury securities. A norm portfolio is built to compare the performance of the NWF’s investments. On average, the NWF has outperformed the norm portfolio on recent years, but it may not always have been optimal. Recent studies suggest that allocation limits should be revised over time as the return and risk parameters may change over time. This study focused on simulating three different portfolios where the allocation limits and investment options were extended to see if these extensions would outperform the norm portfolio while maintaining a set risk limit. Portfolio A consisted of OMRX REAL and OMRX TBOND indexes, Portfolio B consisted of OMRX REAL, OMRX TBOND and S&P Sweden 1+ Year Investment Grade Corporate Bond Indexes, and Portfolio C consisted of OMXR REAL, OMRX TBOND and OMXSPI indexes. The return of each portfolio for different weight distributions of the assets were simulated in MATLAB, and polynomial regression models were built in order to optimize the return as a function of the assets’ weights using a Lagrange Multiplier approach for each portfolio. The results depicted that the maximal returns of Portfolios A, B and C were 4.00%, 4.13% and 7.93% respectively, outperforming the norm portfolio’s average return of 3.69% over the time period 2009-2016.

It is a generally agreed internationally that high level nuclear wastes containing long-lived radioactive wastes should be disposed in deep and stable geological formations that are 500-1000 m below ground level. Deep geological disposal is based on the concept of multiple barriers to prevent deep ground-waters, present in almost all rock formations, from rapidly leaching the wastes and transporting radioactivity away from the repository. The multiple barrier system comprises of ‘engineered barriers’ that are constructed in the repository and ‘natural barriers’ in the surrounding geological environment. The engineered barrier components comprise of the vitrified solid waste, canister (to contain the vitrified waste), and a buffer or backfill material (clay or cement) that fills the annular space between the canister and the walls of the hole drilled in the floor of host-rock. The natural barrier is provided by the rocks and soils between the repository and earth’s surface. The canisters containing the hig level waste (HLW) upon placement in DGR need protection against tectonic activities and chemical attack by dissolved elements and from microbes. Densely compacted bentonite is identified suitable for this purpose owing to its large swell potential, low permeability, sufficient bearing capacity and high cation adsorption capacity. In the deep geological repository (DGR) for disposal of high level nuclear wastes, iodine-129 is one of the significant nuclides, owing to its long half-life (half life = 16 million years) and tendency to easily migrate out of the geological repository into the biosphere caused by its high solubility and poor sorption onto most geologic media. Bentonite buffer by virtue of negatively charged basal surface has negligible affinity for retention of iodide anions. Attempts have been made to improve the iodide retention capacity of bentonite by treating the clay with cationic polymers, this however occurs at the cost of reduced swelling ability of bentonite clay. The compacted bentonite employed in deep geological repositories must possess large swell potential to enable it to close fissures and cracks that form on drying of the expansive clay by the heat arising from the high level nuclear waste and thereby close pathways for migration of radionuclides (from breached canister) to the geo-environment. Therefore, it becomes important to identify an additive that enhances the iodide retention ability of the mix without significantly impairing its swelling ability. Based on the strong affinity of silver for iodide ions, the feasibility of mixing silver-kaolinite (termed AgK) clay with bentonite to improve the latter’s iodide sorption capacity and the impact of mixing AgK clay with bentonite on swelling ability of the mix forms one of the the focus of this thesis. Silver-kaolinite clay was prepared by heating 80% kaolinite + 20% silver nitrate mix at 400°C for 30 min, followed by washing (to remove unreacted silver nitrate) and oven-drying the resultant AgK clay. Physical mixing of AgK and bentonite was considered a viable proposition as small additions (10% to 20% on dry mass basis) besides imparting iodide sorption ability was expected to have minor influence on the swelling ability of the mix. As organo-bentonites are known to retain iodide ions, it was considered relevant to compare the iodide removal behaviour of AgK and organo¬bentonite clay. Hexadecylpyridinium-bentonite (termed as HDPy+B) is the organo¬bentonite examined in this thesis and is prepared by treating bentonite with hexadecylpyridinium chloride mono hydrate salt (C21H38ClN.H2O; molecular weight = 358.01). The hexadecylpyridinium chloride mono hydrate salt is a cationic quaternary ammonium compound and has been used by earlier researchers to prepare organo-bentonite for removal of iodide ions from aqueous solutions. The impact of mixing AgK and HDPy+B clays on the iodide retention and swelling behaviour of bentonite is also considered in the thesis. The mass-balance calculations, XRD analysis, X-ray photon emission survey spectrum and EPMA tests performed on kaolinite-silver nitrate mix/AgK/kaolinite specimen indicated that silver occurs as uniform coatings of AgO/Ag2O on kaolinite surface of the AgK specimen. The AgK clay has strong affinity for iodide ions reflected by the large distribution coefficients (Kd) values of 1367 and 293 mL/g at initial iodide concentrations of 750 mg/L and 1000 mg/L. Further, the sorption process was rapid, unaffected by the presence of co-ions, elevated temperature of sorption and was practically irreversible at range of pH conditions. The iodide retention by AgK is attributed to occurrence of hydrolysis and exchange reactions. On contacting the AgK with water, the AgO species hydrolyze to form AgOH; iodide ions are retained by replacing the hydroxyl group of AgOH leading to formation of AgI phase. The adsorption of HDPy+Cl- ions by bentonite occurs by replacement of the native exchangeable cations by HDPy+ ions and adsorption by van der Waals interactions between the organic cations and the clay surface. The adsorbed cationic polymer neutralize the negative charge of the clay surface. Zeta potential measurements of HDPy+B specimen indicated that adsorption of cationic polymer transforms the negatively charged clay particles into positively charged particles that favour anion adsorption. Sorption of iodide ions by HDPy+B specimen exhibits two distinct segments: 1) the iodide sorption increased rapidly at lower iodide concentration (91 mg/L to 475 mg/L) and are retained by Coulombic adsorption to the cationic groups contained in the loops and tails of the adsorbed polymer (primary adsorption sites) and 2) the relatively slower adsorption at higher iodide concentrations (larger than 475 mg/L) is attributed to exchange with chloride ions attached to HDPy+Cl-ion pair (secondary adsorption sites). The Kd values for iodide adsorption vary from 15 mL/g to 184 mL/g at initial iodide concentrations of 91 mg/L to 996 mg/L respectively. Comparing the iodide removal efficiencies of AgK and HDPy+B specimens revealed that the AgK clay exhibited larger iodide removal; further while the iodide removal by AgK specimen was almost instantaneous (complete in < 5 min), iodide removal by HDPy+B specimen was a slow process (18-24 h is needed to attain equilibrium). Likewise, the iodide retention capacity of the 50%B-50%HDPy+B mix (B = bentonite) is substantially smaller than of the 90%B-10%AgK and 80%B¬20%AgK mixes. Cation exchange capacity (CEC) measurements brought out that mixing AgK with bentonite besides imparting an iodide retention capacity essentially retains the large cation exchange capacity of the expansive clay. On the other hand mixing HDPy+B with bentonite imparts a smaller iodide retention capacity to the mix and leads to a notable reduction in the CEC of the expansive clay. Results of oedometer swell tests brought out that dilution of bentonite with 10% and 20% AgK specimen does not impact its swell potential and leads to some (10%) reduction in swell pressure, while dilution with 50% HDPy+B clay leads to notable (58%) reduction in swell potential and swell pressure (21%) underlining the superiority of AgK specimen as additive to bentonite in deep geological repositories. The swell pressure of the compacted 50%B-50%HDPy+B mix is 21% lower than that of the compacted bentonite specimen. Comparatively, dilution of bentonite with 10% and 20% AgK specimen induces 8-10% lower swell pressure in comparison to the undiluted counterpart. Swell pressure results of compacted 80%B-20%HDPy+B mix is not considered as this mix was unable to retain iodide ions. Superposing the field 129I concentration levels on I removal efficiency indicate that use of 90%B-10%AgK mix would suffice to provide 100% iodide removal efficiency and ensure that the swelling characteristics of bentonite is least affected by dilution.

This dissertation has three aims: 1. To evaluate several ethical theories about responsibility towards future generations. 2. To construct a theory about responsibility towards future generations. 3. To carry out an ethical evaluation of different nuclear waste management methods. Five theories are evaluated with the help of evaluative criteria, primarily: A theory must provide future generations with some independent moral status. A theory should acknowledge moral pluralism. A theory should provide some normative claims about real-world problems. Derek Parfit’s theory provides future generations with full moral status. But it is incompatible with moral pluralism, and does not provide reasonable normative claims about real-world problems. Brian Barry’s theory provides such claims and a useful idea about risk management, but it does not provide an argument why future generations ought to exist. Avner de-Shalit’s theory explains why they ought to exist; however, his theory can not easily explain why we ought to care for other people than those in our own community. Emmanuel Agius’ theory gives an ontological explanation for mankind’s unity, but reduces conflicts of interests to a common good. Finally, Hans Jonas’ theory shifts the focus from the situation of future generations to the preconditions of human life generally. However, his theory presupposes a specific ontology, which might be unable to motivate people to act. The concluding chapters describe a narrative theory of responsibility. It claims that we should comprehend ourselves as parts of the common story of mankind and that we ought to provide future generations with equal opportunities. This implies that we should avoid transferring risks and focus on reducing the long-term risks associated with the nuclear waste.

Legal regulation of a deep geological repository of nuclear waste Abstract The topic of the thesis is the legal regulation of a deep geological repository of nuclear waste in the legal system of the Czech Republic. The thesis aims to summarize the administrative law aspects of preparation, construction, operation and termination of operation regarding the deep geological repository, while simultaneously analyzing legislation regulating the deep geological repository. The structure of the thesis corresponds with this aim, and reflects the phases of preparation and existence of the repository. First part of the thesis, following the introduction, defines the principal legal terms in nuclear waste handling and its disposal. The second part is dedicated to the legislation regarding the repository, including international and European legislation as well as national legislation. In this part, the thesis briefly characterizes the new Atomic Act. The chapter about the national legislation also contains a characteristic of Nuclear Law and mutual relations between regulations regarding the repository. The third part contains institutional and financial aspects regarding the repository. A brief analysis of subsidies provided to regions according to the Atomic Act is included in this part. The fourth part summarizes...

Long lived radioactive species such as ¹²⁹I⁻ and ⁹⁹TcO₄⁻ are formed as by-products of nuclear fission. These species have extremely long half-lives (1.5 million and 211,000 years respectively), are biologically assimilating and due to their anionic nature, can move freely within a geosphere. Historical disposal methods for active species are no longer considered acceptable to the general public and other ways in which to treat the waste are being explored. One remove and concentrate method to remove radioactive species from the biosphere is using alkaline-resistant materials which trap active species that can be encapsulated in a high pH concrete matrix. Layered hydroxides and layered double salts which consist of positively charged layers between which exchangeable anions and water molecules lie are good candidates for these materials due to the basic conditions in which they form. The synthesis, anion exchange properties and stability of copper, lanthanum, nickel and zinc hydroxysalts have been investigated. The structures consist of layers of edge-sharing metal hydroxide octahedra together with an interlayer space containing the anion and in some cases water molecules. Products were characterised by powder X-ray diffraction and vibrational spectroscopy to confirm the identity of structure of the material formed and the anion incorporated. Only Cu2(OH)3(NO3), Cu2(OH)3(OAc).H2O, Ni2(OH)3(NO3) and Zn5(OH)3(NO3).2H2O consistently exhibited exchange capabilities with iodide as the target anion. In terms of exchange rate and efficiency, copper hydroxyacetate is a more suitable precursor as equilibrium is achieved in 10 mins; whereas other LHS containing nitrate as the occupying require longer than 1 day to reach equilibrium. Cu2(OH)3(Ac).H2O has been shown to easily exchange acetate for monovalent anions X- (X = Ha-, NO3-, ClO4-, IO4-, SbO3-, OH-). Exchange reactions with ReO4- (used as a surrogate to TcO4-) and trigonal pyramidal monovalent anions (such as IO3-) were unsuccessful. Exposure to divalent anions (CO32-, Cr2O42-, SeO3-) resulted in no interaction whereas exposure to trivalent PO43- forms Cu3(PO4)2. Quantitative analysis has shown that, contrary to XRPD and FTIR data, full exchange of acetate for an equimolar amount of iodide within a Cu2(OH)3+ framework does not occur with 100% efficiency. Activity counting, gravimetric analysis and ion specific probe analysis suggested that only ~92-93% exchange occurs. The stability of TcO4- and I- analogues with respect to pH has been investigated. Activity counting has shown that even in pH 9.5 solution, 57-73% of 125I- and 99TcO4- immobilised with a Cu2(OH)3+ framework is leached into solution after 16 days. Exposure of Cu2(OH)3I to high carbonate, nitrate and chloride environments shows a progressive loss of iodide into solution as the anionic radius of the incoming anion decreases and the concentration of the incoming anion increases. In the case of chloride and nitrate incoming anions, only a 2:1 chloride to iodide ratio is need for full exchange whereas a ratio of 10:1 nitrate to iodide is required. In situ ion exchange experiments at Diamond allowed the exchange of the hydroxyacetate material to be investigated in flow experiments showing similar facile exchange as demonstrated under batch conditions. Rietveld refinements on deuterated samples of halide analogues of the materials have allowed accurate structure determinations for the first time (Cu2(OD)3Cl - a = 5.726Å, b = 6.125 Å, c = 5.634 Å, β = 93.100°, Cu2(OD)3Br - a = 6.085 Å, b = 6.144 Å, c = 5.650 Å, β = 93.593°, Cu2(OD)3I - a = 6.587 Å, b = 6.179 Å, c = 5.680 Å, β = 95.044°). As the size of the halide increases, the hydroxide coordination alters reflecting to changing sigma/pi donor capability of the halide.

<p>Water and vapour flows from land to sea and the atmosphere are important for water resources, coastal ecosystems and climate. This thesis investigates possible methods for modelling these flows under often encountered unmonitored hydrological conditions and data limitations. Two contrasting types of drainage basin and associated data limitation/availability cases are considered: the Swedish unmonitored near-coastal catchment areas Forsmark and Simpevarp, for which detailed spatial but not much temporal variability data is available; and the much larger Aral Sea Drainage Basin (ASDB), for which spatial hydrological information is limited, while there is relatively well-known temporal change occurring in the Aral Sea itself and in the land and water use of the region over the last 50 years.</p><p>The hydrologic modelling for the Forsmark and Simpevarp catchment areas showed that the relatively large focused stream flows, and the mean values and total sums of the diffuse small stream-groundwater flow fields in between the large stream flows from land to sea are largely constrained by the catchment hydrological balances and relatively robust and certain to estimate. The ASDB hydrologic modelling indicated an evapotranspiration return flow to the atmosphere from the irrigation water input on irrigated land that is much higher than previous estimates in atmospheric modelling, implying possible considerably larger than previously estimated non-local water and climate effects of the world’s irrigated areas. The more detailed groundwater-seawater dynamics modelling carried out for the coastal parts of the ASDB showed that regional topography and bathymetry largely influence coastal water fluxes during sea level lowering, with the Aral Sea shrinkage decreasing the seawater intrusion risk into the coastal groundwater considerably more for steeper than for flatter coastal topography parts of the region.</p>