With its continuous proton beam of world-leading power (1.4 MW), the HIPA facility at the Paul Scherrer Institute (PSI) represents one major asset in the line-up of Swiss large-scale research infrastructures. A recent Swiss Research Infrastructures Roadmap Application from PSI and the University of Zurich (UZ) for 2025-28 named Isotope and Muon Production with Advanced Cyclotron and Target...
The Euratom Treaty provides the legal basis for “promoting and facilitating nuclear research in the Member States and for complementing it by carrying out a Community research and training programme” [1]. The Treaty also established the Joint Research Centre (JRC), which is part of the European Commission. The EURATOM Research and Training (R&T) Programme defines the objectives and priorities...
The nuclear propulsion in application for space probes is developing constantly during last sixty years. At the beginning of those times the world superpowers were working also on nuclear jet propulsion for airplanes, where the heat from combustion of chemical fuel was substituted by the heat generated by nuclear reactors. Since the risk related with crash of airplane having nuclear reactor...
In contrast to the strongly shielded 4 f electrons of the lanthanides, 5 f electrons of particularly the early actinides are found to participate in bonding, e.g. to organic ligands. Reactivity and complexation strength of such bonds are the most influenced by donor properties of the ligand and the electronic situation of the actinide metal center. Furthermore, coinciding properties of...
The United Kingdom has one of the largest and most diverse nuclear waste inventories in the world arising from Magnox, AGR, PWR and prototype reactors. In part, this reflects the country’s long history of reactor development and operation, but the issue has been compounded by frequent changes in government policy. Proposals for disposal of low (LLW) and intermediate level (ILW) waste...
Due to the “German Energiewende”, all nuclear power plants (NPPs) in Germany will have been shut down by the end of 2022. Consequently, a safe, economical, and efficient dismantling of the NPPs will be an important challenge for the next decades. This includes to progress with methods for optimal planning and implementation of decommissioning.
Several studies have been conducted to develop a...
N-donor and O-donor ligands form strong, ninefold coordinated complexes with trivalent actinide and lanthanide ions. These excellent coordination properties make them suitable for the application as extractants and are interesting systems to study from a fundamental scientific perspective. Extraction studies have shown that N-donor ligands (e.g. nPr-BTP) are suitable for the selective...
Trivalent actinides generally exhibit ninefold coordination in solution. nPr-BTP, a tridentate nitrogen donor ligand, is known to form ninefold coordinated 1:3 complexes, [An(nPr-BTP)$_3$]$^{3+}$ (An = U, Pu, Am, Cm) in solution.
We report the first Cm(III) complex with tenfold coordination in solution [Cm(nPr-BTP)$_3$(NO$_3$)]$^{2+}$. This species was identified using time-resolved laser...
Concepts for the safe disposal of high-level radioactive waste in deep geological formations to ensure isolation from the biosphere are based on a multi-barrier system. Cementitious materials are one component of the geotechnical barrier, used as backfill material, for borehole sealing and to enforce the mechanical stability of tunnels. Calcium silicate hydrate (C-S-H), the principal binding...
All isotopes of the elements with atomic numbers 114 and above as well as many of the longer-lived isotopes of lighter superheavy elements are only accessible in fusion reactions with actinide targets. Accordingly, the production of actinide targets is an important topic in the field of SHE research, especially with new accelerator facilities coming online that deliver ever more intense...
As studies on the retention of radionuclides in natural systems over geological times are not feasible, it is common practice to resort to natural analogues. The coprecipitated actinides and homologues of the equivalent oxidation state in secondary mineral phases are a good approximation to estimate the radionuclide retention potential of such minerals.
Fracture fillings formed within...
Already in the frame of the first scientific project sponsored by the IAEA with the title “Factors controlling the distribution of fission products in the biosphere” in the early 1960ies of the last century, air filters and lung autopsy samples from people, who had been living in Vienna, Austria, were collected and investigated with regard to short-lived fission products from the nuclear...
Radionuclide speciation inside long-term radioactive waste repositories needs to be understood in order to ensure effective containment of the waste. Organic ligands originating from the degradation of organic components inside such a repository can possibly affect the mobility of radionuclides in solution. The present study focuses on nitrilotriacetic acid, NTA, as a model molecule and...
The batch sorption method of measuring radionuclide distribution between the crushed, sieved solid phase and liquid phase is commonly used for obtaining sorption coefficients Rd/Kd. These are often crucial input parameters used in reactive transport models for estimating a possible future radionuclide release from a radioactive waste repository [1]. Therefore, it is extremely important to...
This contribution provides an overview of a current research network funded by the German Federal Ministry of Education and Research (BMBF), entitled “Fundamental investigations of actinide immobilization by incorporation into solid phases relevant for final disposal” – AcE. The AcE project aims at understanding the incorporation and immobilization of actinides (An) in crystalline,...
The decommissioning of nuclear facilities will produce all levels of radioactive waste, including intermediate- and high-level waste that is not allowed to be disposed of in low- and intermediate-level radioactive waste repositories. Therefore, it is necessary to find infill materials used in a deep geological repository that will make it safe for the environment for a long period of time. The...
Cement-based materials are used as engineering barriers for low-level and intermediate-level radwaste and in high-level radwaste disposal as facilities or buffer materials. To evaluate the long-term safety of radioactive waste repositories, it is necessary to describe the behavior of stored radionuclides that will be present, such as europium used as an analog of trivalent actinoids. The...
Abstract
By its geographical position, Algeria in general and its Northern part in particular is not far from any radioactive contamination originating from nearby countries, especially industrial ones.
The activity concentrations of natural radionuclides (namely 210Pb and 7Be) were measured by direct counting gamma spectrometry of particulate matter filters collected at two different...
Overall goal of this project is to contribute to the knowledge of the heaviest actinoids. The research was carried out in two main directions: development of a method for radiochemical separation of actinoid series by liquid chromatography, including a model for determining separation parameters in non-equilibrium processes at one-atom-at-a time level (JINR Dubna), and novel methods for An(II)...
To elucidate the impact of humic acids (HA) on chemical affinity of Co(II) to inorganic sorbents experiments on statics of sorption Co (II) by the Thermoxide T35 (composition ZrO2-K2Ni [Fe (CN)6]) in the chloride-acetate solution are carried out. The dependance of the Co (II) sorption (S) as a function of contacting time, the dependance of distribution coefficient (Kd) on the pH, the...
Actinides are known to form nanoparticles (NP), which were shown to enhance radionuclide transport in the environment. Understanding these processes on the molecular level is therefore of particular interest.
Previous results showed a strong and unusual influence of the background electrolyte on Th sorption on the mica (001) basal plane based on surface x-ray diffraction (SXD) data. Uptake...
High-level radioactive waste (HLW) and spent nuclear fuel (SNF) are planned to be disposed of in many countries in deep-lying geological multi-barrier systems. Groundwater intrusion into deep geological repositories represents a considerable risk of long-lived radionuclides being released from the deposited HLW and SNF. Therefore, the risk assessment of such a scenario plays an integral role...
Introduction
Evaporation of tail solutions from spent nuclear fuel reprocessing is a required activity before high-level waste (HLW) solidification. Evaporation of HLW according to the traditional flow sheets of the 2nd generation reprocessing plants is complicated by an increase of the sediment-forming fission products amount due to a 100-fold increase in SNF burnup, as well as the presence...
Calcite is a common mineral in the environment, comprising approximately 4% of the earth's crust. The surface reactions of calcite play an important role in many geological and environmental systems, including the production of oil and gas, the geological storage of nuclear waste and CO2 etc. For example, the sorption of Ni-63 on calcite affects significantly its mobility and...
Introduction
When dissolving highly burnt spent nuclear fuel (SNF) with obtaining of solutions containing heavy met-als (HM) more than 300 g/L, there is a high probability of secondary precipitation, the composition of precipitants depends on the degree of nuclear fuel burnup and the conditions of its dissolution. When a zirconium molybdate precipitate is formed, a certain amount of plutonium...
To ensure a reliable and long-term safety assessment of high-level radioactive waste disposal, it is essential to study the physico-chemical properties of the radionuclides within spent nuclear fuel as well as their transport behavior expected under conditions of the near- and far-field of a nuclear waste repository. Among the radionuclide inventory, long-lived mobile fission products are of...
Ductile and corrosion resistant cast iron is investigated as a potential container material to store high-level nuclear waste (HLW) in deep geological repositories (DGR) in claystone bedrock. The dynamic corrosion process is dependent on the conditions present in the DGR which are influenced and/or controlled by geochemical parameters (e.g., redox potential, pH, presence of and ionic...
Cement-based materials are used for waste conditioning and as technical barriers in potential nuclear waste repositories. In order to adjust the physico-chemical and mechanical properties of concretes, several additives are added to the cement. Various polycarboxylates with phosphonic acid groups, of which 2-Phosphonobutane-1,2,4-tricarboxylic acid, PBTC, is the most prominent representative,...
Radionuclide speciation inside long-term radioactive waste repositories needs to be understood in order to ensure effective containment of the waste. Organic ligands originating from the degradation of organic components inside such a repository can possibly affect the mobility of radionuclides in solution. The present study focuses on nitrilotriacetic acid, NTA, as a model molecule and...
The decommissioning NPP A1 project is reaching preparation stage of dismantling the reactor KS 150. Graphite reflector shielding, is notable part of reactor internals which must be dismantled, managed and treated.
Radiological characterizations were performed in order to determine 19 limited radionuclides and 36-Cl for LLW repository. Material characterisation was conducted by means of EDS –...
Safety assessment of deep geological repository (DGR) of radioactive waste considers safety functions of all the barriers, including the host rock. In case of Czech DGR the host rock is considered to be crystalline rock, as granite or migmatite. Migration within such a rock is driven mainly by advection in the rock fracture which can be coated with secondary minerals, as calcite or...
Superplasticizers are organic cement additives often used in construction as they improve the properties of concrete. The engineered barriers in repositories for radioactive waste often include cementitious materials. Superplasticizers and their radiolytic and hydrolytic breakdown products and how they might affect the transport properties of radionuclides represent a concern in the long-term...
MSO (Molten Salt Oxidation) is a technology of flame-less oxidation in molten salts. This technology is mainly used to reduce the volume of hazardous solid and liquid wastes and allows the processing of loose materials, semi-liquid suspensions or liquids over a wide range of viscosity. Combustible wastes are fed through the dosing system into the reactor together with air or oxygen. During the...
The batch sorption method of measuring radionuclide distribution between the crushed, sieved solid phase and liquid phase is commonly used for obtaining sorption coefficients Rd/Kd. These are often crucial input parameters used in reactive transport models for estimating a possible future radionuclide release from a radioactive waste repository [1]. Therefore, it is extremely important to...
This contribution provides an overview of a current research network funded by the German Federal Ministry of Education and Research (BMBF), entitled “Fundamental investigations of actinide immobilization by incorporation into solid phases relevant for final disposal” – AcE. The AcE project aims at understanding the incorporation and immobilization of actinides (An) in crystalline,...
Stability & Physico-Chemical Characterisation of Reconditioned Waste Form Relevant to Radioactive Wastes
Gianni F. Vettese1*, Taavi Vierinen1, Jaana Laatikainen-Luntama2, Suvi Lanninmaki2, Markku Leivo2, Emmi Myllykylä2, Matti Nieminen2, Tandre Oey2, Tapio Vehmas2 & Gareth T. W. Law1
1The University of Helsinki, Radiochemistry Unit, Helsinki, Finland
2VTT Technical Research Centre of...
When nuclear facilities, all types of radioactive waste are generated, including intermediate and highly active radioactive waste, which cannot be disposed of in current radioactive waste repositories in the Czech Republic. Therefore, it is necessary to find filling materials used in deep repositories that are environmentally safe for a long time. The aim of the ALMARA project is to study and...
The decommissioning of nuclear facilities will produce all levels of radioactive waste, including intermediate- and high-level waste that is not allowed to be disposed of in low- and intermediate-level radioactive waste repositories. Therefore, it is necessary to find infill materials used in a deep geological repository that will make it safe for the environment for a long period of time. The...
Radioactive waste contains large amount of radionuclides. A radioactive isotopes of caesium (137Cs, half-life time 30 years) and strontium (90Sr, half-life time 28 years) belong to the main fission products existing in the radioactive wastes produced in nuclear power. The ion exchange technology is one of the most commonly used methods for safe treatment of radionuclide waste. Zeolites are...
Cement-based materials are used as engineering barriers for low-level and intermediate-level radwaste and in high-level radwaste disposal as facilities or buffer materials. To evaluate the long-term safety of radioactive waste repositories, it is necessary to describe the behavior of stored radionuclides that will be present, such as europium used as an analog of trivalent actinoids. The...
Geopolymers are promising materials applicable in nuclear industry. They have been tested for various applications like nuclear waste immobilisation, as a construction material, for concrete cracks reparation, etc. We have developed a synthetic route for production of versatile geopolymer material with application in a passive system of GEN IV reactor safety. Such material contains a...
Project introduction
The aim of the ALMARA project is the optimization of infill matrixes for disposal of intermediate and high level wastes from nuclear power plant decommissioning, which fulfil requirements that ensure long term safety of deep geological repository over long term period. The project is also focused on radionuclide interaction and migration with/in the matrix materials...
Introduction
Cements and concretes have been widely used in intermediate/low level waste (I/LLW) management in Czech Republic, being used namely as solidification material. Moreover, cement materials are con-sidered also for disposal of high level waste (HLW) in deep geology repository (DGR), hereby being considered both for solidification and construction materials. 14C was chosen as a...
Metal oxalates are salts of very low solubility allowing an easy precipitation of metal ions from the acidic aqueous solutions into crystalline material. Due to this property, oxalates have an important role in the technology of lanthanides and actinides. It is namely the separation of actinides from the spent nuclear fuel that is its application of interest. 4f-lanthanides are often used as...
A variety of different polymer micelles are applied in the clinic as nano-carriers for chemotherapy. For a safe and effective application, it is imperative to know how they behave in vivo. Here, we present a chelator-free method for radiolabeling of polymer micelles to enable in vivo biodistribution studies. The radiolabeling method is very simple and is achieved by just adding the...
With increased number of nuclear facilities to be decommissioned, radiological characterization of various radioactive waste generated during decommissioning and operation of nuclear facilities is needed for estimation of the total inventory of radioactivity and its variation with time. Among them, determination of hard-to-measure radionuclides is the main challenge. 93Mo is a long-lived (4000...
The interrelationship of NF-κB and related signaling pathways involving NF-κB-related effector genes in adaptive radioresistance has attracted significant current interest toward the overall quest of developing more effective radiotherapeutic agents. Compelling evidence suggests that radiotherapy triggers several signaling pathways including NF-κB and related signaling vectors causing...
The radiological characterization process conducted during the lifecycle of a nuclear facility is paramount in all operative phases of decommissioning, waste management, and site environmental monitoring to enhance safety of workers and public and mitigate the environmental footprint of nuclear technology. Most of radiocesium contamination can be easily detected like 134Cs and 137Cs, and...
Radioisotope 68Ga is used for radiopharmaceuticals synthesis word wide and its application is increasing every year. 68Ge/68Ga generator are the main source of 68Ga for radiolabeled radiopharmaceuticals products such as 68Ga-DOTATOC and 68Ga-PSMA. The price of the generator is quite expensive and due to decaying of 68Ge it is necessary to buy a new one nearly every half year. Another...
Turnaround time and performances of standard analytical protocols may not be compatible with the objectives (contributing to knowledge of the radiological state, detecting an abnormal rise in radioactivity as early as possible…) and the levels of radioactivity present in the environment. Research and expertise programs, implemented to explain or predict radioactivity transfers between the...
The Superheavy Element Factory in Dubna offers unique prospects regarding future chemistry experiments with superheavy elements. The very first chemistry experiment at the Superheavy Element Factory will focus on the chemical characterization of elements copernicium (Z=112) and flerovium (Z=114) in their respective elemental state, employing online gas adsorption thermochromatography. Further...
During the last years, an increased effort was put into the measurement of decay data with high precision, with the ultimate goal of confirming the existent nuclear values and/or lowering their uncertainties. Precise nuclear data is extremely important in the description of galactic events, in the nuclear dating of samples, as well in the evaluation of the toxicity of nuclear waste....
As part of a long-term vision to deploy fusion technology in a scalable path to practical fusion energy, SHINE Technologies has ventured to produce lutetium-177. While a one-of-kind Mo-99 production plant is being constructed, SHINE’s Therapeutics division is currently manufacturing small quantities of 177LuCl3 to support clinical studies for cancer radioligand therapy. SHINE expects a...
The knowledge of complexation reactions of early actinides with nitrogen donor ligands serves not only as fundamental research in this underrepresented field of chemistry but also contributes to a deeper understanding of their reactivity and coordination chemistry. In contrast to the lanthanides, with the dominating oxidation state of + III, actinides, especially the early actinides up to...
Neutron-induced fission of $^{\text{235}}$U leads to a variety of radionuclides. With such targets being hosted in the inner shielding shell of the Swiss Spallation Neutron Source SINQ at the Paul Scherrer Institute, the produced radionuclides can be readily transported to the radiochemical laboratory by the SINQ gas-jet installation. The transport of the resulting fission products occurs...
Phosphate species from natural (e.g. phosphate mineral like apatite) as well anthropogenic (e.g. fertilizers) sources are ubiquitous in the environment [1]. Phosphoric acid is also present in the PUREX process as ultimate degradation product of tributylphosphate [2]. Phosphate species are expected to strongly interact with plutonium ions, plutonium being one of the main environmental...
When on April 26, 1986 the reactor of the Chernobyl nuclear power plant exploded, nuclear fuel was in part released as microscopic solid particles. Structurally intact hot particles pose a risk to humans mainly by the (unlikely) path of inhalation. However, over the decades, weathering may lead to considerable release of radionuclides that subsequently can enter the human food chain. Since hot...
Human nuclear activities including nuclear weapons tests and nuclear accidents have released large amounts of radioactive substances to the environment. Due to the high volatility of iodine and high fission yield of radioactive iodine (129I, 131I), the released radioactive iodine has been dispersed and deposited in a large area. The long-lived iodine-129 is therefore can be used as an ideal...
Iodine is an extremely volatile element naturally present under various organic or inorganic forms. These physico-chemical characteristics complicate its extraction and quantification. Among the 37 iodine isotopes, 127I is the only stable one and 129I is the radioisotope with the longest half-life (16.1 x 106 y). 129I is chronically and regulatory released by fuel reprocessing plants e.g....
Activities related to nuclear energy are at the origin of a dissemination of actinides in the environment. The migration of actinides in the environment is strongly dependent on their speciation and consequently on the pH, the ionic strength, the redox potential but also on the presence of ligands which can promote their mobility. The An(V) ions are, in general, highly soluble leading to a...
Uranium materials are strictly controlled by the international nuclear safeguards system. However, if such materials get out of regulatory control and subsequently seized, a comprehensive measurement is eventually required to assess the posed hazard, intended use and possible origin. Such nuclear forensic analysis focuses on the analysis of these intercepted nuclear or other radioactive...
The interactions of long-lived actinides, such as the transuranium element neptunium, with corrosion products in the near-field of a repository are important processes that have to be considered when assessing the safety of a nuclear waste repository. As a main corrosion product of the zircaloy cladding material of spent nuclear fuel rods, zirconia (ZrO$_{2}$) constitutes a first possible...
Diversification of energy resources in order to tackle climate change and increase energy efficiency triggers a need to deploy more nuclear reactors worldwide, as a stable source of both electricity and heat. The leaching of radioactive elements to the surface waters and groundwaters due to the extraction of uranium as a key component of the nuclear fuel cycle from natural deposits causes an...
Globally, it is estimated that more than two billion people suffer from micronutrient deficiencies. Nutrient-rich foods are at the center of creating healthy and sustainable diets, but supplementation approaches based only on the amount of nutrients fail to consider the bioavailability and thus the uptake potential of these nutrients. Therefore, food matrix-based approaches are essential to...
Radionuclides ingested with food may accumulate in the human body and pose a potential health risk. Radium is a naturally occurring radionuclide, which may be present in drinking water and in certain foods in larger quantities up to ca. 10 Bq kg-1 [1]. Daily consumption of only a few Brazil nuts, which can have activity concentrations of > 200 Bq kg-1 caused by radium [2], may lead to an...
Tc-99 is one of the most important isotopes likely to be disposed of in the proposed UK Geological Disposal Facility for higher-activity radioactive wastes, due to its long half-life, high fission yield and ability to migrate through the geosphere as the pertechnetate ion. However, much of the technetium is likely to be in the lower oxidation state of Tc(IV) due to the low Eh in the near...
ABSTRACT
The desorption of uranium from microplastic surfaces has been investigated as a function of pH in aqueous solutions under ambient conditions. In addition, the effect of complexing ligands (e.g. EDTA, NTA, Citrate) on the desorption from plastic surfaces (including the plastic containment surface) has been studied. The evaluation of the experimental data indicate that the solution pH...
ABSTRACT
The paper describes an alternative approach for the determination of uranium, radium-226 and potassium levels in Brazil nuts. Potassium analysis was performed by a NaI detector using 1-gram of nut’s ashes, radium analysis was carried out by radon emanation measurements after EDTA-mediated ash dissolution, and uranium levels were determined by alpha spectroscopy after acidic...
Krško Nuclear Power Plant (KNPP) is located in south – eastern part of Slovenia, on the left bank of the Sava River. Emissions of the operational Pressurized Water Reactor (PWR) are mainly 14C and 3H. The dam for the Brežice Hydroelectric Power Plant (BHPP) constructed few kilometres downstream has caused changes in the local climate parameters and hydrology around KNPP. The simultaneous...
Radionuclide migration is one of the key problems for the long-term safety of nuclear waste repositories. One possible mechanism to retard or prevent the migration of radionuclides from the repository to the biosphere is the adsorption onto mineral surfaces of the surrounding host rock. Clay rock formations such as the Opalinus Clay are being considered for potential sites for nuclear waste...
Domestication of dogs and cats took place thousands of years ago, altering the behavior and physiology of animals. Since then, the number of pets has increased year after year, reaching nowadays 471 million dogs and 373 million cats in the world. On average, half of a pet's cost of living is related to food, mainly dry kibble. The existence of exclusive pet foods is relatively recent. The...
Sugarcane has been a versatile crop in Brazil and an integral part of its economy by providing key components such as sugar, ethanol and energy. It is the number one source of renewable energy, accounting for 17% of total energy consumption. Sugar is the country´s fourth largest export commodity. Brazil is the world’s largest sugar producer with 34.65 million tons in 2021, maintaining its...
The products of radiolysis and hydrolysis of polyacrylonitrile (PAN) in strongly alkaline conditions were studied using several methods — HRMS, FT-IR and LCMS analysis, combinable HPLC with UV / VIS and refractometry. The studied conditions correspond to the environment formed by cementitious materials utilized as the engineering barrier in the disposals of radioactive waste. Degradation...
Chemical decontamination of nuclear facilities generates large volumes of low-level radioactive waste. Following worldwide efforts to reduce spent chemical reagents and radioactive waste volumes, new methods of regeneration and reuse of spent decontamination solutions are studied. This work focuses on the usage of ionic liquids (ILs) as an organic phase in solvent extraction of strontium from...
Diglycolamides are frequently used as extraction agents in many fields of nuclear and separation chemistry including nuclear waste management, nuclear fuel reprocessing, radioanalytical chemistry, radioecology or nuclear medicine. They are tridentate ligands with extraction abilities to extract trivalent ions, mainly lanthanides and actinides [1].
This ability can be beneficial in separation...
Targeted alpha particle therapy (TAT), which uses radionuclides emitting alpha particles is one of the promising possibilities for the treatment of a broad range of malignancies. A short range of alpha particles in soft tissues (approx. 50-100 μm) and high linear energy transfer (LET) allows to destroy tumor cells effectively. Precise targeting by appropriate carrier should ensure efficient...
The interaction of highly mobile radioactive elements in the spent fuel with the different technical and geological barriers of a nuclear waste repository needs quantification and mechanistic understanding to allow a reliable safety assessment.
One of the most concerning mobile fission products is Tc-99. It is a long-lived radionuclide (half-life of 0.213 million years) that is expected to...
Specific and unique equipment – decontamination loop - for the practical training of the students in the field of decontamination was devised and designed at the Department of Nuclear Chemistry, CTU in Prague, and it was manufactured by Wood Nuclear Slovakia s.r.o.
The decontamination loop is a modular system intended for study of various decontamination methods and procedures. For this...
To enhance the therapeutic efficacy of radioimmunotherapy of cancer, several pretargeting strategies have been developed. In pretargeted radioimmunotherapy, the tumour is pretargeted with a modified monoclonal antibody that has affinity for both, tumour antigen and radiolabeled carrier. A big challenge in cancer treatment is the elimination of occult disseminated tumour cells, in this context...
Short-lived, very low-level radioactive wastes (VLLW) will be stored in near surface repositories in many countries, including Finland, Sweden and the UK. Very low-level radioactive wastes may be produced whilst operating or decommissioning a nuclear power plant, as medical waste or as naturally occurring radioactive materials. Here, most radionuclides have half-lives less than 30 years and...
The paper describes the influence of various organic solvents on the performance of a newly designed scintillation cocktail. The work mainly focuses on the sample load capacity of the scintillation cocktail in connection with the solvent component to be able to accept the largest possible volume of different types of samples, especially aqueous ones. Previous research has dealt with the ideal...
In case radionuclides (RN) enter the food chain and are incorporated by humans, they pose a possible health risk due to their radio- and chemotoxicity. In case of such incorporation, HEDP (1-Hydroxyethylidene-1,1-diphosphonic acid; etidronic acid) and DTPA (diethylenetriaminepentaacetic acid; pentetic acid) are common decorporation agents for uranium and transuranium RN, respectively....
Lots of reports about inhalation risk and external exposure caused by negative ion technology products which include toiletry, wristbands, clothing, and bed mattresses. Negative ion technology can involve the use of minerals that contain a naturally occurring source of radiation such as thorium or uranium. Hassan et al. investigated thirteen NORM-added negative-ion products in terms of organ...
In case radionuclides (RN) enter the food chain and are incorporated by humans, they pose a possible health risk due to their radio- and chemotoxicity. To precisely assess the health risk after oral incorporation of RN with food and beverages and to apply effective decontamination methods, it is mandatory to understand the processes of RN biokinetics on both cellular and molecular scale....
Ra-223 dichloride injection is a new type of alpha-emitting therapeutic radiopharmaceutical. To accurately measure the radioactivity of Ra-223 is very important for drug dose control and assessment of various potential contamination events. Gamma spectrometry, with the advantage of simple sample pretreatment and high accuracy, is the first choice for Ra-223 activity measurement. The most...
The conversion of soluble U(VI) to insoluble U(IV) is an economic strategy to efficiently remove U(VI) from radioactive wastewater by photoreduction. However, high photogenerated electron-hole recombination rate and low sunlight utilization are still huge challenges. Here, we designed a carbon nitride-based heterojunction composite material for photocatalytic reduction of U(VI) from aqueous...
ABSTRACT
The paper describes an alternative approach for the determination of uranium, radium-226 and potassium levels in Brazil nuts. Potassium analysis was performed by a NaI detector using 1-gram of nut’s ashes, radium analysis was carried out by radon emanation measurements after EDTA-mediated ash dissolution, and uranium levels were determined by alpha spectroscopy after acidic...
Radionuclides with high radiotoxicity and long half-life derived from nuclear industry activities would inevitably be introduced into the soil or groundwater. In order to propose a safe and efficient method to control the migration of radionuclides, it is of great significance to understand the environmental behavior of nuclides. The laboratory experiments and field studies have proven that...
Molybdenum-93 (T½ = (4.0±0.8)·103 years) is significant long-lived radionuclide contained in the treatment of nuclear waste. 93Mo is formed when a molybdenum rich material is exposed to thermal radiation, especially by neutron capture by 92Mo. Molybdenum occurs as an impurity e.g., in steels in the core area, in the coolant, etc.
Several studies were published with procedures of separation of...
ABSTRACT
Τhe separation and determination of uranium in calcareous samples (e.g. calcite, phosphogypsum and phosphate rock) has been investigated by means of alpha-spectroscopy after dissolution of the samples by nitrilotriacetic solution (NTA), uranium separation by cation-exchange and electrodeposition on stainless steel planchets. Method recovery as well as uranium analysis and isotopic...
Krško Nuclear Power Plant (KNPP) is located in south – eastern part of Slovenia, on the left bank of the Sava River. Emissions of the operational Pressurized Water Reactor (PWR) are mainly 14C and 3H. The dam for the Brežice Hydroelectric Power Plant (BHPP) constructed few kilometres downstream has caused changes in the local climate parameters and hydrology around KNPP. The simultaneous...
In this study, we present a novel approach for C-14 analses of iron material.
C-14 contamination of iron materail could happen in nuclear reactors, where the neutron flux could produce significant amount of C-14 atoms inside the iron based construction elements (vessel wall, tubes, etc). If those elements are going to be disposed in waste, than the C-14 concentration should be measured,...
ABSTRACT
The desorption of uranium from microplastic surfaces has been investigated as a function of pH in aqueous solutions under ambient conditions. In addition, the effect of complexing ligands (e.g. EDTA, NTA, Citrate) on the desorption from plastic surfaces (including the plastic containment surface) has been studied. The evaluation of the experimental data indicate that the solution pH...
The Federal Ministry of Climate Action, Environment, Energy, Mobility, Innovation and Technology funded a monitoring project of the current status of the activity concentration in Austrian groundwater. Measurements of uranium-isotopes (U-238, U-235 and U-234) were part of this project.
The uranium isotopes concentration was determined using two different analytical methods - inductively...
The presence of colloids in groundwater can enhance radionuclides transport by loading on colloid to co-transport. The mechanism of co-transport is difficult to be fully revealed based on macroscopic experimental observations because the co-transport process cannot be monitored in situ. Hence a reliable model of colloid and nuclide co-transport is needed. Considering that colloid transport...
Below ground level at Prague Castle there is several remainders of ancient buildings and structures which have been of interest of intense archaeological research since thirties of the 20th century. One of them, part of the so-called Small Excavations of the Third Courtyard is the Romanesque corridor. As most of these underground structures, it is not accessible to public. The passage was part...
Uranium mineralization hosted in sedimentary rocks is exposed in the roadcut. The sediments are of lakustrine origin with a high proportion of organic matter and enriched in uranium and several other potentially hazardous elements. The most remarkable are two mineralized uranium-rich sulphide-bearing bitumen (thucholite) veins with locally high contents of U (up to the order of wt.%). The...
The first Accelerator Mass Spectrometry (AMS) laboratory in the Czech Republic has recently been established within a consortium of Nuclear Physics Institute (NPI) of the Czech Academy of Sciences (CAS), Faculty of Nuclear Sciences and Physical Engineering of the Czech Technical University in Prague (CTU in Prague – FNSPE) and the Institute of Archaeology of the Czech Academy of Sciences,...
Radionuclides ingested with food may accumulate in the human body and pose a potential health risk. Radium is a naturally occurring radionuclide, which may be present in drinking water and in certain foods in larger quantities up to ca. 10 Bq kg-1 [1]. Daily consumption of only a few Brazil nuts, which can have activity concentrations of > 200 Bq kg-1 caused by radium [2], may lead to an...
The analysis of illicit drugs composition is required for effective actions of Law Enforcement Agencies. Determination of major as well as trace elements provides additional parameters that could help in identification of drugs origin. Heroin, cocaine and methamphetamine samples were assayed by instrumental neutron activation analysis (INAA) for determination of mass fractions of several...
The assay of in-situ terrestrial cosmogenic nuclides (TCN) $^{10}$Be and $^{26}$Al is central to a geo-archaeological project aimed at determining the age of cultural Layer VII. representing a possible Early to Middle Pleistocene (Lower Palaeolithic) hominin occupation at Korolevo, Transcarpathia, western Ukraine. The cobbles (quartz, quartzite and sandstone) from the Layer VII. fluvial...
Domestication of dogs and cats took place thousands of years ago, altering the behavior and physiology of animals. Since then, the number of pets has increased year after year, reaching nowadays 471 million dogs and 373 million cats in the world. On average, half of a pet's cost of living is related to food, mainly dry kibble. The existence of exclusive pet foods is relatively recent. The...
Sugarcane has been a versatile crop in Brazil and an integral part of its economy by providing key components such as sugar, ethanol and energy. It is the number one source of renewable energy, accounting for 17% of total energy consumption. Sugar is the country´s fourth largest export commodity. Brazil is the world’s largest sugar producer with 34.65 million tons in 2021, maintaining its...
Tritium and radioactive carbon generated by the operation of nuclear facilities are radionuclides with half-life of 12.3 and 5730 years, respectively, so if leaked, it will have a significant long-term impact on the environment and humans, so continuous monitoring is required.
In the case of radioactive carbon dioxide, it is fixed in living organisms through respiration of animal and plant or...
Fragments of archaeological pottery are one of the most common artefacts excavated in archaeological sites. However, radiocarbon dating of these artefacts nor their total lipid extracts have not brought reliable radiocarbon results due to wide spectrum of carbonaceous compounds from various reservoirs which contributed to the overall lipid composition. The only possibility is to use a...
Carcinogenity of residential radon (222Rn) is already scientifically discredited. Positive correlation between radon and lung cancer is based on LNT (Linear-no-threshold-theory) only. No correlation here, when assumption-free statistics applied. On the other hand, radon is successfully used in balneology due to its strong hormetic effects.
In radon balneotherapy, in some cases, the natural...
Radon-222 is a radioactive noble gas omnipresent in the environment. Being part of the U-238/Ra-226 decay chain, it has been found to considerably contribute to the radiation dose to the public. Exposure to Rn-222 at home and workplace has been extensively monitored and specific guidelines exist to mitigate exposure. Rn-222 has also gained considerable attention in particle physics research,...
The importance of the uranium speciation study, specifically in the alkaline environment of cement-based materials, stems from the conditions that can be expected in low and intermediate level waste repositories and also deep geological repositories for spent nuclear fuel, in their section for the storage of high-level decommissioning waste. In addition to its common construction function,...
Introduction
Nuclear energy is a green and renewable energy. Uranium, as an important resource for nuclear energy, exists in seawater at a concentration of 3.3 μg/L, forming highly stable Ca-UO2-CO3 and Mg-UO2-CO3 complex. Though dilute, this amounts to an estimated 4.5 billion tons of uranium, which is approximately 1000 times more than that is available from conventional sources such as...
The Monitoring of natural radionuclides in groundwater samples has been carried out in various projects in Austria over the last 25 years. A large project monitoring groundwater samples from all over Austria took place in 2008 and 2009. Building on this, a follow-up project was launched in 2021, funded by the Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and...
Extraction chromatography is widely used in radioanalytical methods for the separation of actinides. The most commonly applied extractants for the separation of tetravalent actinides are quaternary amines (e.g., in TEVA resin), tetra- and hexavalent actinides are often separated with trialkyl phosphonates (e.g., in UTEVA resin), and tri-, tetra- and hexavalent ones can be separated using...
In routine radiochemical analyzes of water, especially drinking water, in recent years we have analyzed more than 4,000 water samples for uranium 238U, 235U and 234U isotope contents by ICP/SFMS method in the ALS Scandinavia AB laboratory, Luleå, Sweden and the Central Analytical Laboratory of ÚJV Řež, a.s., Husinec – Řež, in the Czech Republic. By statistical processing of an extensive set of...
Since the introduction of the first commercial 68Ge/68Ga generator about 20 years ago, interest in 68Ga-labelled radiopharmaceuticals is steadily increasing. Currently, over 400 clinical studies including 68Ga are being executed. Additionally, several PET imaging agents were approved for clinical use by the FDA, the latest being a new prostate-specific imaging agent, potentially leading to a...
Natural uranium (U) in deep groundwater has been extensively studied in connection to the search for suitable locations for final disposal of spent nuclear fuel (SNF). The U removal process depends on environmental and geochemical conditions and is often associated with fractionation of the main ‘stable’ isotopes, 238U and 235U (denoted as δ238U), during reduction of hexavalent (U(VI)) to...
The A-CINCH (“Augmented Cooperation in education and training In Nuclear and radioCHemistry”) project is the latest project in the series of CINCH projects and it is corroborating and extending previous achievements. For such purpose, A-CINCH augments CINCH teaching tools developed in the three previous CINCH projects – CINCH, CINCH II and MEET-CINCH – the CINCH project series...
The cold neutron beam at MLZ offers unique conditions for nuclear analytical chemistry. The analytical facility accommodates several instruments being under development or recently upgraded. This paper summarizes the progress, and the possibilities these instruments offer.
The focusing guide is being replaced with a truly-curved elliptical guide ensuring a more homogeneous beam with a smaller...
Nuclear and radiochemistry contains key knowledge and techniques needed by a modern society in order to address societal challenges including the energy sector, medical treatment and diagnosis, material sciences and dating. In order to maintain a high level of expertise, continued education and training is required on all levels using current digital media and attractive, efficient teaching...
Recently, the NAA instrument has been fully integrated into the MLZ user system. The FRM II reactor features various short and long high-flux irradiation positions in a well-thermalized neutron field in the range of 10$^{13}$–10$^{14}$ cm$^{–2}$s$^{–1}$ with a thermal-to-epithermal ratio up to 12,000. The counting of the irradiated samples take place in a near laboratory of the Radiochemie...
In the last decades Massive Open Online Courses (MOOCS) have emerged and continued to grow, gaining recognition worldwide. MOOCs have the unique merit to enable to reach the widest number of users worldwide and offer them high-quality e-learning materials. However, even if completely free and always online, a MOOC could remain a treasure in the hands of few, especially when dealing with unique...
The growth in demand for quality beef has stimulated the production of animals with superior genetics. Genetic breedings gave rise to cuts of meat with high added value. Cattle breed certification programs have been created in Brazil to assist in the transparency of the production chain and attest to specific quality attributes of certain breeds. However, this mechanism is not enough to...
In the recent years the loss of expertise in the nuclear- and radio-chemistry (NRC) is becoming an issue of concern in many aspects. Although this discipline is essential in many fields, few engaging curricula, few career prospects, along with a misperception of this subject, is causing a serious lack of NRC expertise in many parts of the world.
In the attempt to contribute to limiting this...
Vehicle crimes are often associated with the production of glass fragments. Shards found on the crime scene and microfragments attached on suspect clothing are traces available for Law Enforcement Agencies. The refractive index is often used as a parameter for glass profiling. As an additional characterization, chemical composition of glass fragments was studied by instrumental neutron...
Engineered biopolymers have received a great deal of interest for environmental remediation of radionuclides in recent years. Composites derived from alginate, chitin or activated biochars
exhibit promising uptake capacities for common and problematic radionuclides such as strontium, cesium and uranium due to a wide range of surface functionality, extensive multiscale porosity, and excellent...
Copper at low levels is generally considered an essential element. It can be determined by neutron activation analysis (NAA) via 63Cu(n,γ)64Cu and 65Cu(n,γ)66Cu reactions. The positron-emitting nuclide 64Cu (half-life=12.7 h) is not commonly used because of interferences. The short-lived 66Cu (half-life=5.09 min) can possibly be used in instrumental NAA (INAA). However, it is seldom done in...
The management of radioactive waste requires an accurate description of source terms
and their behavior in natural or engineered barriers. Many radioactive waste involve organic
contaminants, either included in the source term (e.g. 14C bearing lixiviates of graphite waste)
or released simultaneously with radionuclides (e.g. degradation products of plastics or
adjuvents in cementitious...
In the framework of Collaborative Materials Exercises (CMX) organized by the Nuclear Forensics International Technical Working Group (ITWG) we received 4 radioactive samples S1 – S4 of unknown origin in two different physical forms (2 powders, 2 metal pieces), which contained unknown content of uranium with unknown enrichment and were asked to answer the following questions:
1) Do samples...
To evaluate the long-term safety of low/intermediate level radioactive waste repositories and future deep geological repositories for spent nuclear fuel, it is necessary to investigate the behaviour of radionuclides that will be present, such as uranium or lead. Radionuclide migration is affected by interactions with engineering barriers of the repositories, which may also include sorption of...
Accelerator mass spectrometry (AMS) is a very sensitive analytical method for determination of ultra-trace concentrations of long-lived radionuclides in environmental samples. Plutonium isotopes Pu-239, 240 are anthropogenic alpha emitters with a half-life of 24 and 64 thousand years, a commonly monitored in the environment due to plutonium radiotoxicity. In practice, AMS measurement of...
Zirconia (ZrO2) doped with lanthanides or actinides has been extensively studied for several tailored applications, such as for the immobilization of actinides present in high-level radioactive waste streams (HLW) or as inert matrix fuel for the incineration of e.g. waste plutonium. Doped zirconia matrices have been reported to have a very high radiation tolerance, however, inconsistencies...
Multiple strategies have been developed to separate lanthanides (Ln) and actinides (An) from Spent Nuclear Fuel (SNF) and PUREX raffinate through solvent extraction. Current research is focusing on the development of new ligands to separate Am(III) from Cm(III) and other fission Ln(III). Diglycolamides (DGA) such as N,N,N′,N′‐tetra-n-octyl diglycolamide (TODGA) are promising extractants for...
Radiocarbon analyzed in isotopic archives such as tree rings and marine sediments have been used for tracing past as well as recent climate changes caused by Sun-Earth orbital parameters, solar activity cycles and by increases of green-house gases in the atmosphere. The most visible past climate cycles were represented by Milankovitch cycles, as documented by observed O-18 and Be-10 variations...
An innovative-SANEX process for the selective separation of the trivalent actinides americium and curium from a simulated PUREX raffinate solution was successfully demonstrated on the laboratory scale using a 16-stage 1 cm annular centrifugal contactor setup. The solvent was composed of 0.2 mol L−1 N,N,N',N'-tetra-n-octyl-diglycolamide (TODGA) and...
E. Macerata1, F. Galluccio1, A. Ossola1, E. Mossini1, M. Giola1, P. Weßling2, C. Adam3, A. Geist3, P. J. Panak2, W. Panzeri5, M.C. Gullo6, A. Casnati6, A. Mele4,5, M. Mariani1
1 Department of Energy, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan, Italy
2 Ruprecht-Karls-Universität Heidelberg, Institut für Physikalische Chemie, Im Neuenheimer Feld 253, 69120 Heidelberg,...
The European Union has a long-term objective to reduce greenhouse gas emissions causing global warming. In 2005, the so-called Kyoto Protocol entered into force, which introduces a system of emission allowance (EUA) that creates gradually increasing financial pressure on companies emitting CO2. This agreement distinguishes between carbon, which comes mainly from the combustion of fossil fuels...
The measurement of alpha and beta radioactivity is something common in several fields (i.e. environmental monitoring, medicine, research…) although there is still a necessity for more environmentally respectful methods with a low generation of residues and new strategies for complex scenarios, like continuous monitoring or fast methods for the analysis of difficult to measure radionuclides...
Radionuclides released from nuclear accidents can be widely distributed and even enter the human food chain. If ingested, they interact with the fluids from the digestive system and can cause necrosis or carcinogenesis of human cells. To remove these radionuclides, decorporation agents are used. Clinical approved decorporation agents like ethylenediaminetetraacetic acid (EDTA) or...
The assessment of the sample radioactivity content through global or screening parameters is of interest since it permits to obtain valuable information about the presence of radionuclides in samples. This strategy has the advantage that avoids the use of laborious selective procedures for each radionuclide which are usually long and complex, leading to the generation of more information in...
Ionizing radiation in the molten salt reactor environment will drive chemical changes in the composition of the salt and induce additional pathways for corrosive degradation of reactor components. Although the products of radiolysis are largely expected to recombine in the high-temperature molten salts, even a small mechanistic leakage out of the recombination cycle will result in substantial...
The americium isotope Am-241 is formed during the storage of plutonium via beta-decay of Pu-241 with a half-life of 14.33 years. Due to its accumulation in existing stocks of civil separated plutonium in Europe, and its relatively high specific power of 0.114 W/g, Am-241 has been proposed for use in radioisotope power systems (RPS) and is under consideration by the European Space Agency (ESA)...
Introduction
Amidinate ligands have attracted considerable attention in the field of coordination chemistry over the last decades as versatile soft N-donor ligands to stabilize the transition metal complexes in various oxidation states. The additional advantages of employing amidinates over other ligand systems are their high modularity and easy access to a variety of analogs by...
Combined external beam radiotherapy and chemotherapy are known to have much more favourable disease outcome due to synergistic working, e.g., DNA repair inhibition by drugs making ionizing radiation more potent. However, anti-tumour drugs are known to cause severe adverse effects since they attack healthy fast dividing cells besides cancer cells. To minimize the systemic toxicity of such...
In preparation of gas phase chemical experiments with element 115, we studied the chemical behavior of single short-lived bismuth atoms in rare gases (helium and argon) and in oxygen atmosphere. For that purpose, we performed off-line isothermal gas chromatography experiments at room temperature. The short-lived volatile Rn-219 precursor, provided from an Ac-227-source, was transported into...
In the past, the effects of high dose rate of low-LET radiation on the radiation-chemical yields of liquid chemical dosimeters have been systematically studied only for the case of microsecond-length pulses that delivered high peak doses (> 100 Gy). In this study, yields of four different chemical dosimeters were determined at very high dose rates (~1012 Gy/s) but at low peak doses...
Understanding of fundamental aspects of metal behavior is a key component of controlling the separation and purification process. This knowledge is based on speciation and oxidation state information leading to numerical thermodynamic parameters [1-3]. Surprisingly, there are still chemical systems with unknown stability constants of metals in the generic mineral acids. However, this situation...
Presently transportation is responsible for nearly a third of greenhouse gas emissions worldwide and is one of the major contributing factors to global warming. [1] Renewable energy sources in combination with electrochemical devices for energy storage have partially been able to mitigate these problems. It is conceivable to replace traditional combustion engines with environmentally friendly...
The determination of the enthalpy of adsorption of an analyte on a defined stationary surface is one of the most important methods for the determination of chemical properties of superheavy elements (SHEs). Isothermal gas-adsorption chromatography setups have been used in various experiments to chemically study compounds of rutherfordium (Rf, Z=104), dubnium (Db, Z=105), seaborgium (Sg,...
The use of MOx with high plutonium contents as a fast reactor fuel is under consideration to help manage plutonium inventory. These plutonium contents are above those typically reprocessing and posse a number of challenges. Increased plutonium content makes the fuel dissolve more slowly and leads to an increase in plutonium-rich residues. Increasing the dissolver cycle time to allow for the...
Bismuth-213 (213Bi) is an alpha-emitting radioisotope with large potential in nuclear medicine for cancer treatment. Several clinical trials of 213Bi-based radiopharmaceuticals have provided evidence for its therapeutic efficacy. 213Bi is produced from the relatively long-lived parent nuclide actinium-225 (225Ac) and then separated in a radionuclide generator. The patient dose of 213Bi is...
The reprocessing of spent nuclear fuel is currently moving towards advanced cycles that contemplate the recycling of minor actinides (MAs: Am, Cm, Np), as a strategy to minimise the radiotoxicity of the waste that must be stored [1]. One of the constraining points for the development of extraction processes from the point of view of safety is their resistance to the highly radioactive field...
With recent advances in the use of novel radiolanthanides for targeted Auger electron therapy, the request for precise and controlled dosimetry has increased in importance. So far, no experimental data for the energy and branching ratios of Auger electrons have been reported for Auger-electron-emitting lanthanides. One of the main challenges related to such measurements is the production of a...
Lead-bismuth eutectic (LBE) is a eutectic alloy composed of 44.5 at% Pb and 55.5 at% Bi. It is of particular interest as a possible coolant for the Generation IV nuclear reactors and accelerator-driven systems (ADS) given its good thermophysical properties (low melting point, low vapor pressure, and good thermal conductivity) and inertness towards reactions with water and air. However, the...
The main objective is to develop a new production route for high specific activity molybdenum-99 based on the irradiation of molybdenum nanoparticles. In order to achieve this, molybdenum nanoparticles have been produced by spark ablation.
The spark ablation technology provides an easy method to produce nanoparticles with controlled size. It consists of a gas phase physical process in which...
The Thermal Oxide Reprocessing Plant (THORP) at Sellafield has reached its end-of-life and is about to be decommissioned. One of the first steps to reducing the hazards associated with the plant is Post-Operational Clean Out (POCO). As part of this process, a large amount of radioactive metallic waste is required to be managed through the waste hierarchy, with one of the key stages being...
Cancer is a disease that still kills nearly 10 million people every year [1] despite the countless existing treatments. The amount of novel therapies is growing every day and targeted alpha therapy is one of them. Herein, the patient is treated with a radiopharmaceutical that binds to the cancer cell and emits ionizing radiation to induce cell damage. Since alpha radiation has a very short...
In radiochemistry, liquid extraction is widely used to concentration and separation of elements. Often, upon contact of two immiscible liquids, interfacial formations (cruds) are formed in the area of the interface, which reduce the rate of extraction, worsen the separation of the emulsion, and complicate the process. Sometimes a precipitate is formed that disrupts the operation of the...
By definition a cumulative production cross section of a radionuclide includes formation via direct nuclear reactions and formation via radioactive decay of the precursor nuclide (considering isomeric transition too). In literature different definitions of the cumulative cross sections exist.
The solution of the coupled differential equation describing the radioactive growth and decay for a...
Introduction
Radioembolization is a specific type of internal radiotherapy used to treat primary or metastatic hepatic tumors. The basis of this therapy is the intra-arterial insertion of microspheres containing beta radioactive yttrium in the vicinity of the tumor tissue. The aim of the work was carried out physical and biological experiments performed to determine radiometric parameters and...
As a part of a project aiming at the post-fabrication modification of 3D-printed objects by radiation processing, we are currently investigating the formation of gold nanoparticles by irradiating poly(hydroxyethyl methacrylate) (PHEMA)-based hydrogels, swollen with aqueous Au(III) solutions.
The radiolytic behavior of PHEMA has apparently not been deeply investigated nor reported in the...
The ability to work remotely has been critical for the past two years due to the pandemic. Many students were hindered in developing their experimental skills due to restricted access to campus and laboratories. A partial remedy to such situations can be to provide remote access to physical laboratories. This enables a student to perform real experiments without being physically present. In...
Initially, the catalyst was modified in an oxygen medium under the influence of surface radiation. The conversion processes were compared on the surface of compacted and unmodified catalysts, in the range ∆T = 380 ÷ 420oC, the yield of gaseous and liquid products from the conversion of hexane in a mini-flow reactor was studied. The output of the products was monitored with IR and UV...
⁹⁹Tc (T1/2 = 2.1·10⁵ y) is an abundant product of the nuclear fuel cycle which is lying at the low-mass peak in the ²³⁵U fission fragment spectrum. ⁹⁹Tc accounts for 6.1% of the fission product mass in (²³⁵U-enriched) nuclear fuels following burn-up in a reactor. In the environment, Tc also occurs due to nuclear bombs atmospheric testing and nuclear medicine. Tc is taken up by several plant...
The natural organic matter present in uranium deposits (coal, amber-like fossil resins, bitumen) plays an important role in the transport, accumulation and mineralization of uranium in sediments, and it is also a sensitive marker allowing characterization of the depositional and diagenetic history of sedimentary formations. The energy transferred by ionizing radiation to organic matter can...
Background: To enhance the therapeutic efficacy of radioimmunotherapy of cancer, several pretargeting strategies have been developed. In pretargeted radioimmunotherapy, the tumour is pretargeted with a modified monoclonal antibody that has affinity for both, tumour antigen and radiolabeled carrier. A big challenge in cancer treatment is the elimination of occult disseminated tumour cells,...
Specific and unique equipment – decontamination loop - for the practical training of the students in the field of decontamination was devised and designed at the Department of Nuclear Chemistry, CTU in Prague, and it was manufactured by Wood Nuclear Slovakia s.r.o.
The decontamination loop is a modular system intended for study of various decontamination methods and procedures. For this...
Abstract
The sorption of ultra-trace levels of polonium by Luffa Cylindrica biochar fibers has been investigated in de-ionized water and seawater samples prior and after surface modification (Ag-coating) of the adsorbent. The effect of pH on the sorption efficiency (Kd values) indicated that pH, which governs the solution chemistry of Po(IV), affects to a large degree the adsorption...
Chemical decontamination of nuclear facilities generates large volumes of low-level radioactive waste. Following worldwide efforts to reduce spent chemical reagents and radioactive waste volumes, new methods of regeneration and reuse of spent decontamination solutions are studied. This work focuses on the usage of ionic liquids (ILs) as an organic phase in solvent extraction of strontium from...
Targeted alpha particle therapy (TAT), which uses radionuclides emitting alpha particles is one of the promising possibilities for the treatment of a broad range of malignancies. A short range of alpha particles in soft tissues (approx. 50-100 μm) and high linear energy transfer (LET) allows to destroy tumor cells effectively. Precise targeting by appropriate carrier should ensure efficient...
One of the strategic aims of the FNSPE is the education of experts for the Czech nuclear industry and research and for the state authorities which are dedicated to the peaceful employment of nuclear energy. By creating the new all-faculty specialized programme “Decommissioning of Nuclear Facilities” FNSPE flexibly react to the needs of the labour market in which a critical shortage of experts...
Isotopes of molybdenum, the fission products arising from 235U fission, represent one of the contaminants in liquid radioactive waste generated in the nuclear fuel cycle. With regard to the half-life of 93Mo, this isotope becomes important for safety assessment for disposal sites in long term of deposition of radioactive wastes. Conventional processes for its separation are mostly based on...
Photodynamic therapy (PDT) is a clinical treatment that uses light to activate a photosensitizer which produces reactive oxygen species (ROS) able to destroy tumor cells. Photosensitizers are nontoxic in dark until they are activated by a specific wavelength of light and then generate different ROS, such as singlet oxygen 1O2, superoxide anion (·O2-) and hydroxyl radicals(·OH), which are quite...
Diglycolamides are frequently used as extraction agents in many fields of nuclear and separation chemistry including nuclear waste management, nuclear fuel reprocessing, radioanalytical chemistry, radioecology or nuclear medicine. They are tridentate ligands with extraction abilities to extract trivalent ions, mainly lanthanides and actinides [1].
This ability can be beneficial in separation...
Terbium-161 is one of the perspective radionuclides with a potential use in nuclear medicine thanks to its ideal energy of beta radiation (E$_\beta$$_{max}$ = 593 keV) and half-life (6,9 d). In addition, terbium-161 emits a significant amount of conversion and Auger electrons, which increases its potential therapeutic efficacy. Terbium-161 can be prepared as no carrier added by neutron...
Radiation- and photo-chemical synthesis is a promising tool for large-scale preparation of nanocrystalline powder scintillators. Our studies to date include many scintillating material groups: simple oxides (Al2O3, ZnO, ZrO2, HfO2) or multicomponent oxides, namely garnets (YAG, LuAG, GGAG, etc.). Photochemical method also allows the preparation of non-oxidic materials, for example sulfides...
In the context of spent nuclear fuel (SNF) disposition, a deep geological repository (DGR) based on a multi barrier concept is considered in many countries as the safest and most sustainable disposal option. The licensing of such a DGR is challenging and demands amongst others, safety assessments considering time frames of up to one million years. Moreover, a profound understanding of the...
Increased reactivity of radiation-damaged quartz in the alkaline pore water of concrete and its role in radionuclide transport is a subject that is becoming increasingly important as nuclear power plants (NPPs) around the world reach end-of-life. Quartz contributes more than half the weight of most concretes and up to 40 % of the total radioactive waste volume associated with the dismantling...
To improve the efficiency of nuclear reactors by extending the fuel cycle, burnable neutron absorbers, such as Gd2O3, have been extensively added in the PWR and BWR fuels to control the reactivity due to their large neutron absorption cross-section. Doped fuels must be safely stored after their life cycle in a deep geological repository, therefore their behaviour in case of canister failure...
Presence of uranium in both natural and anthropogenic waters creates demand for the new ways of systematic monitoring of its concentration. New analytical electrode based on powdered graphene and modified with specifically designed zeolite sorbent and similar to well-known and widely used graphite paste electrode, [1], has been tested for the ability to analyze the uranium content in aqueous...
Uranium Nitride (UN) is a potential candidate for the advanced technology fuels (ATF) concept, as it has numerous benefits compared to conventional uranium oxide (UO2) used today. Namely, higher thermal conductivity and uranium density. UN main drawback is its poor corrosion resistance in oxidizing environments. Doping of UN with oxide scale forming elements such as chromium could improve the...
Tritium is a radioactive beta emission isotope of hydrogen with a mass of 3.0 and is mainly present as tritiated water(HTO) in wastewater discharged from nuclear facilities.
However, since HTO and H2O have very similar physical and chemical properties, it is very difficult to separate a trace amount of HTO mixed in a large amount of water (H2O). There is a commercialized isotope exchange and...
Just in Western Europe, more than 160 nuclear facilities should be closed by 2025. This process requires the management of all the elements with a potential content of radioactivity, in order to determine if there are long live radionuclides present and need to be stored in a deep geological repository, if short live radionuclides are present and need to be temporary stored for its decay or if...
Extraction properties and radiation stability of two systems with hydrophobic extractants (CyMe4-BTBP or CyMe4 BTPhen) and three systems with hydrophilic masking agents ((SO3H)2-BTP, (SO3H)2-BTBP or (SO3H)2 BTPhen) were studied throughout the GENIORS project.
The study of extraction systems containing CyMe4-BTBP or CyMe4-BTPhen dissolved in fluorinated BK-1 diluent revealed that the...
Composite sorbents based on nanoparticles of NiO, NiO-TiO2 and ZrO2-TiO2 were chosen for treatment of spent decontamination solutions based on citric acid. Active oxidic materials were prepared by photoinduced synthesis (NiO, NiO-TiO2) or hydrolytic method (ZrO2-TiO2). Weight distribution ratios for radionuclides 241Am, 60Co, 137Cs a 90Sr/90Y and others were investigated in the course of the...
In case radionuclides (RN) enter the food chain and are incorporated by humans, they pose a possible health risk due to their radio- and chemotoxicity. Therefore, it is necessary to know the biokinetic processes as well as the speciation of the RN after ingestion in order to develop and improve specific methods for their decorporation. When RN are ingested orally, they first come into contact...
The work deals with a complex topic of liquid-liquid extraction of Mo and W from the Sg point of view, which puts emphasis on extraction rate and efficiency. The topic can be divided into three main areas of focus: exploring the possibility of employing industrial grade extraction agent Cyanex 600 for extraction of group 6 elements from nitric acid solutions, suggesting the extraction...
In case radionuclides (RN) enter the food chain and are incorporated by humans, they pose a possible health risk due to their radio- and chemotoxicity. When RN incorporation occurs, decorporation agents (DA) play a critical role in health maintenance and reduction of toxicological damage. Since excretory organs are highly exposed to incorporated RN, we performed in vitro cell culture...
Hydrogen isotopes are studied in many research areas to clarify fundamental and applied aspects of their physicochemical behavior. Besides deuterium, the isotope tritium has become the focus of current investigations. One important application is the separation of hydrogen isotopes. Currently available methods have low separation efficiency and high energy consumption. Therefore, approaches to...
Natural radionuclides can be concentrated in coal ash and slag. When such a waste is deposited in the environment, it is normally inhabited by different animals and plants. Earthworms are one of the most exposed as they live in close contact with such a waste throughout their entire life. Po-210 and Pb-210 represent one of the most radiotoxic radionuclides, especially when ingested. Within...
The understanding of the formation of the elements has been an intriguing topic within the last decades. It is now approved that the heaviest naturally occurring elements on earth, the actinides, are produced in the astrophysical r-process. However, the exact site of this process is still disputed. Recently, the amount of interstellar $^{244}$Pu (T$_{1/2}$ = 80.6 Ma) in various geological...
Radionuclides may have damaging consequences for ecosystems and may present variable threats for biota, if released from repository or mining areas. In soils, bioavailable radionuclides may affect adversely to microbiological activity and vitality, cause changes in community structure and inhibit the growth of microorganisms. On the other hand, soil microbiota can modify soil chemical...
The effect of unmodified and functionalized Spirulina platensis biomass silver nanoparticles on rats during prolonged oral administration was assessed. Silver nanoparticles were characterized by using transmission electron microscopy, while their uptake by the biomass was confirmed using scanning electron microscopy and energy dispersive analysis. The content of silver in the different organs...
As part of the space experiment “Test”, a roll of cotton cloth fixed on the outer surface of the International Space Station for more than 10 years was delivered to the Earth in September 2019. The elemental composition of two fragments of the cloth, contaminated and clean, was determined using instrumental neutron activation analysis at the IBR-2 reactor. Along with 19 elements (Mg, Al, Cl,...
National Research Tomsk Polytechnic University (TPU), together with an industrial partner (BEBIG), start produced yttrium microspheres at its research nuclear reactor this fall. This radiopharmaceutical is intended for the treatment of liver cancer in inoperable patients and, unlike analogs, it destroys the tumor in a targeted manner without affecting healthy organs and tissues.
Irradiation...
Among the modern analytical methods, laser spectroscopy, Instrumental Neutron Activation (INAA), and mass spectrometry analysis are the leading techniques for the detection of trace amounts of different isotopes in complex matrices providing the breadth of information about the elemental and isotope composition [1-10].
We report on chemiluminescence of plutonium, uranium, and samarium in...
There was studied the conversion of cellulose into liquid and gaseous products in the high-temperature range under the influence of ionizing radiation. There was found that at high temperatures, the yield of gaseous products prevails at the values of the absorbed dose D≤10 kGy, and at higher doses, the yield of liquid and solid phase products prevails. This is due to the processes of...
RADIOLYTIC PRODUCT DISTRIBUTION IN SELF-IRRADIATED AND GAMMA IRRADIATION SOLID STATE $CA^{14}CO_{3}$: NEW DATA
Abstract.
Both auto-radiolysis and gamma irradiation induce transformations in solid powdered $Ca^{14}CO_{3}$. Liquid chromatography followed by liquid scintillation counting were used to identify eight compounds after aqueous dissolution of the irradiated samples. The...
