Long-term Storage Facility Research Articles

Understanding post-irradiation creep behavior of M5Framatome zirconium alloy

After in reactor use, the nuclear fuel assembly of pressurized water reactors is stored in water and is eventually transported, in a dry cask, to a long-term storage facility or to a reprocessing plant. During transportation in dry environment the fuel rod temperature and internal pressure both increase. This leads to simultaneous creep deformation and annealing of the cladding tubes made of M5Framatome11M5 and M5Framatome are trademarks or registered trademarks of Framatome or its affiliates, in the USA or other countries. zirconium alloy. This study shows that post-irradiation creep, or heat treatment, leads to the recovery of the radiation induced hardening and also to the recovery of the uniform elongation because of <a>-loop annealing. On the other hand, it is shown that cladding tubes made of M5Framatome alloy exhibit low post-irradiation creep rates, especially at low applied stress. This strain rate is significantly lower than for the unirradiated material and similar to the as-irradiated material, despite the significant <a> loop annealing. The low creep rates are mainly attributed to the Nb-rich nano-precipitates that act as dispersed strengthening particles. These nano-precipitates appear under irradiation and are stable at temperatures up to 450 °C explaining their strengthening effect even after significant annealing.

A Blueprint for a Contemporary Storage Element, building a new WLCG storage system with widely available hardware and software components: Ceph, XRootD, and Prometheus

When a new long-term storage facility was needed at the Lancaster WLCG Tier-2 Site, an architecture was chosen involving CephFS as a failure-tolerant back-end volume, and load-balanced XRootD as an endpoint exposing the volume via the HTTPS/DAVS protocols increasingly favoured by the WLCG and other users. This allows operations to continue in the face of disc/node failures with minimal management, and enables good utilization of network connectivity for remote access. We deployed a Prometheus/Loki/Grafana monitoring/alerting stack for timely detection and resolution of failures in such a production environment. Some custom scripts were required to adapt the off-the-shelf functional components with monitoring. With such a monitoring system in place, failures such as disc defects, data corruption and resource exhaustion in long-running processes can be anticipated, and their management planned. We describe the hardware platform and our requirements on it, and detail the software architecture from initial design, through adaptations to face challenges encountered during production, to present condition. Developments and contributions to related projects that help to fully exploit our design decisions are described. We include performance metrics of the system, the lessons learned during production, and our future plans.

Determination of &lt;sup&gt;90&lt;/sup&gt;sr in natural waters and water from observing wells at radioactive waste long-term storage and final disposal facilities

The optimal conditions for pre-concentration of 90Sr from natural water samples by a T-3K carbonate-containing zirconium dioxide were determined. A method for determination of 90Sr in natural water samples was developed using the T-3K sorbent; the method provides as low detection limits as 0.03 Bq/L for 1L water samples and 0.02 Bq/L for 2L water samples. The method was tested on monitoring of 90Sr in natural water bodies at Sverdlovsk and Chelyabinsk regions as well as in waters of control and observation wells on the territory of a radioactive waste long-term storage facility. It was shown that the developed method can be used without control of strontium chemical yield in case of natural water samples containing up to 76 mg/L of Ca and 5.2 mmol/L of hardness salts taking into account the average strontium chemical yields of 91 ± 1% for 1L water samples and 81 ± 2%, for 2L water samples. In case of water samples with a higher hardness, the dependences of strontium yield on Ca concentration or hardness presented in this paper may be used for evaluation of strontium yield.

Determination of 90Sr in Natural Reservoirs and Waters of Control and Observation Wells of Long-Term Storage and Disposal Facilities of Radioactive Waste

Determination of 90Sr in Natural Reservoirs and Waters of Control and Observation Wells of Long-Term Storage and Disposal Facilities of Radioactive Waste

Silica gel free region and rare earth metal extraction correlations in reprocessing bauxite residue

The solid waste, bauxite residue, is the main sustainable development challenge for the alumina industry as large volumes of the material must be maintained indefinitely in long-term storage facilities unless complete site remediation can be achieved. Efforts in bauxite residue reutilization have recently shifted from its use as an additive in cement and ceramics manufacturing to development of processes for the extraction and production of metals and metal compound products. A hydrometallurgical approach is considered here and factors such as reaction temperature, time and acid concentration were examined to systematically characterize the leaching behavior of critical rare earth elements and how they correlate among each other and with major elements in the bauxite residue. The study showed that, within the reaction time, low temperature and low acid concentrations primarily caused release of Al, Si and a minority of La, while a majority of Fe coupled with Ce, Sc or V dissolved when higher temperatures and acid concentrations were applied. The statistical significance of the correlations was confirmed by analysis of correlation coefficients among elemental concentrations in leachates using machine learning mathematical models. Management of silica gel formation is a challenge in the hydrometallurgical treatment of bauxite residue, therefore, the silica gel free formation region was identified. Based on the stability field of silica gel formation, a stepwise acid leaching process for bauxite residue is proposed to facilitate downstream processing of the critical metals.

The history of seed banking and the hazards of backup.

Seeds and other plant materials in seed and gene bank collections are rarely considered adequately conserved today unless genetically identical duplicate samples have been created and safely stored elsewhere. This paper explores the history of seed banking to understand how, why and with what consequences copying collections came to occupy this central place. It highlights a shift in the guiding metaphor for long-term preservation of seed collections, from banking to backup. To understand the causes and consequences of this shift in metaphor, the paper traces the intertwined histories of the central long-term seed storage facility of the United States (opened in 1958) and the international seed conservation system into which that facility was integrated in the 1970s. This account reveals how changing conceptions of security, linked to changing economic, political and technological circumstances, transformed both the guiding metaphors and the practices of seed conservation in these institutions. Early instantiations of long-term cold storage facilities vested security in robust infrastructures and the capacities of professional staff; between the 1960s and 1990s, this configuration gave way to one in which security was situated in copies rather than capacities. This observation ultimately raises questions about the security promised and achieved through present-day infrastructures for crop genetic resources conservation.

A study on texture stability and the biaxial creep behavior of as-hydrided CWSR Zircaloy-4 cladding at the effective stresses from 55 MPa to 65 MPa and temperatures from 300 °C to 400 °C

The creep rupture of high burnup used nuclear fuel (> 45 GWD/MTU) cladding is regarded as one of the failure mechanisms during long-term dry storage. A high amount of zirconium hydride in the cladding matrix would degrade the mechanical properties of the cladding especially leading to delayed hydride cracking. To better understand the influence of zirconium hydride on the biaxial thermal creep performance and the crystalline texture stability of Zircaloy-4 cladding, the pressurized tube technique is applied to test the durability of the as-hydrided material. Tests were performed on as-received Zircaloy-4 tubular specimens as well as-hydrided ones with targeted 300 wt parts per million (wppm) or 750 wppm hydrogen. The biaxial creep experiments were conducted at temperatures from 300 °C to 400 °C and at equivalent stresses at mid-wall from 55 MPa to 65 MPa. The hydridation process prior to creep tests induces the formation of FCC δ-hydride platelets along the circumferential direction of the tube. This alignment and phase structure of hydride show no significant change after biaxial creep tests. The creep strain-rate negatively depends on the hydrogen content. The synchrotron wide-angle X-ray diffraction (WAXD) technique and electron backscatter diffraction (EBSD) analysis were applied for the study of the crystallographic orientation relationship. zirconium-to-hydride grain orientation follows Shoji–Nishiyama crystallographic relationship. This relationship is stable before and after creep deformation. These results of creep performance and texture stability of Zircaloy-4 claddings can help support the design basis of interim and long-term dry storage facilities.

Hybrid Energy System Model in Matlab/Simulink Based on Solar Energy, Lithium-Ion Battery and Hydrogen

In this work, a model of an energy system based on photovoltaics as the main energy source and a hybrid energy storage consisting of a short-term lithium-ion battery and hydrogen as the long-term storage facility is presented. The electrical and the heat energy circuits and resulting flows have been modelled. Therefore, the waste heat produced by the electrolyser and the fuel cell have been considered and a heat pump was considered to cover the residual heat demand. The model is designed for the analysis of a whole year energy flow by using a time series of loads, weather and heat profile as input. This paper provides the main set of equations to derive the component properties and describes the implementation into MATLAB/Simulink. The novel model was created for an energy flow simulation over one year. The results of the simulation have been verified by comparing them with well-established simulation results from HOMER Energy. It turns out that the novel model is well suited for the analysis of the dynamic system behaviour. Moreover, different characteristics to achieve an energy balance, an ideal dimensioning for the particular use case and further research possibilities of hydrogen use in the residential sector are covered by the novel model.

Indigenous Seeds, Seed Selection and Seed Bank for Sustainable Agriculture

Indigenous seeds are grown by the farmers over the years with a strong influence from local natural factors. Such seeds have a higher level of intrapopulation variations and the capacity of buffering the adverse factors. Understanding indigenous seeds along with their diversity are useful to diversify their uses, to assess conservation status, to know the factors making farming areas red zone, and to improve their performance. Selection is the simplest and most common method for the improvement of crop varieties. The variation must be created and maintained to impose selection. Different types of selection can be considered depending on the mode of reproduction of crops. Response to selection and correlated response are estimated to make the selection process more effective. Many different selection approaches can target either developing monomorphic or polymorphic varieties. There are five selection units and can be applied in five crop stages. Farmers’ criteria need to be considered during selection process. Based on the genotypic classes, there are three types of selection namely stabilizing selection, directional selection, and disruptive selection. The most simple and common selection methods are pure lines, mass selection, and class-bulking selection. Orthodox seeds in short, medium, and long-term storage facilities are conserved as a seed bank. Major types are household seed banks, community seed banks, national seeds, natural seed banks, and global seed banks. A seed bank is for assuring the availability of crop diversity for research, study, and production. The common works in seed banks are diversity collection, regeneration, characterization, multiplication, and distribution along with online database management.

FROM NATURAL GAS TO GREEN HYDROGEN

Since hydrogen usually exists on Earth as part of a compound, it has to be synthesized in specific processes in order to be used as a product or energy source. This can be achieved by different technical methods, and various primary energy sources, – both fossil and renewable fuels, in solid, liquid or gaseous form, – can be used in these technical production processes. Hydrogen has only a very low volumetric energy density, which means that it has to be compressed for storage and transportation purposes. The most important commercial storage method, – especially for end users, – is the storage of hydrogen as a compressed gas. A higher storage density can be achieved by hydrogen liquefaction. Novel materials-based storage media (metal hydrides, liquids or sorbents) are still at the research and development stage. The storage of hydrogen (for example, to compression or liquefaction) requires energy; work is, in present, on more efficient storage methods. Unlike electricity, hydrogen can be successfully stored in large amounts for extended periods of time. For example, in long-term underground storage facilities hydrogen can play an important role as a buffer store for electricity from surplus provided by renewable energies. At present, pure hydrogen is generally transported by lorry in pressurize gas containers, and in some cases also in cryogenic liquid tanks. Moreover, local/regional hydrogen pipeline networks are available in some locations. Another solution for storage and transportation are Liquid Organic Hydrogen Carriers (LOHC) that can use long pipe networks and ships. In the near future, the natural gas supply infrastructure or oil (transportation pipelines and underground storage facilities) could also be used, in specific conditions, for the storage and transportation of pure or blended hydrogen with methane. This could be essential for transition because most important primary energy source for hydrogen production currently is natural gas, at 71%, followed by oil, coal and electricity (as a secondary energy resource). Steam reforming (from natural gas) is the most commonly used method for hydrogen production. In this new light, the article explores the trend and prospects for hydrogen, presented in the literature, as a source of energy competing with gas and oil resources in the global energy system of the future.

Summary and analysis of Russian and international requirements for the safe management of very low level radioactive waste and production waste containing very low active radionuclides

This article gives an overview of Russian legislation and international recommendations on the safe management regulation of the accumulated very low level radioactive waste (RW), provides the comparison of Russian and international criteria for RW attribution to this or that class and also the existing radiation safety requirements. This article also deals with the difficulties in management of production waste containing radionuclides. Criteria and standards were selected from international (ICRP and IAEA publications) and Russian (Federal Law on Management of Radioactive Waste, Government Decree on Radioactive Waste Classification, The Basic Sanitary Rules of Radiation Safety) documents for comparative analysis. International and Russian criteria for the radioactive materials attribution to RW and production waste containing radionuclides were compared during the analysis. A number of radionuclides for which it is necessary to establish such criteria have been identified. It was found that Russian classification of radioactive materials is generally consistent with IAEA classification. Practices of managing production waste containing radionuclides (protection from contact with the environment, the placement in the long-term storage facilities or disposal) depend on the period of potential hazard of radionuclides. The management of production waste containing radionuclides requires a separate system which should be developed in accordance with the RW management system.

Double-pathway arsenic removal and immobilization from high arsenic-bearing wastewater by using nature pyrite as in situ Fe and S donator

Nonferrous smelting wastewaters containing high levels of arsenic and sulfuric acid threaten human health and ecological environments due to insufficient disposal technologies and/or possible leakages during transportation to long-term storage facilities. Chemical precipitation is one important route for arsenic removal and immobilization via the formation of arsenic-stabilized minerals. In this study, we propose a new strategy for the treatment of wastewaters containing high levels of arsenic using pyrite as an in situ S and Fe source to prepare environmentally friendly scorodite and As2S3 precipitates. Dissolved pyrite release (S-II) and Fe (II) ions in highly acidic wastewater, both of which drive arsenic precipitation. Sulfide ions readily react with As(III) to generate the stable As2S3 while Fe(II)/As(III) were oxidized to Fe(III)/As(V) by H2O2. The reaction between Fe(III) and As(V) took place on the pyrite surface as a nucleation site to form amorphous ferric arsenate that ultimately transformed into crystalline scorodite. Sulfide ions were oxidized to H2SO4 that further promoted pyrite dissolution. Up to 99.4% of arsenic was successfully removed from copper smelting wastewaters with an initial arsenic concentration of 11200 mg/L. The concentration of leached As from the As-bearing precipitate was 1.78 mg/L under optimized conditions, which were: a 1.4 FeS2/As molar ratio, an initial solution pH of 2, an H2O2/As molar ratio of 1%, a reaction temperature of 90 °C, and a reaction time of 12 h. In summary, a prospective process successfully shows arsenic removal and immobilization from smelting wastewater, and further demonstrates the potential for the efficient and affordable disposal of wastewater.

A fuzzy chance-constrained programming model for integrated planning of the wheat supply chain considering wheat quality and sleep period: a case study

Wheat is a staple food in many countries, and as a result, the first most cultivated crop worldwide. Since wheat is a vital product in terms of food security, and its supply chain needs to be studied and planned carefully. This paper proposes a mixed-integer linear programming model for integrated planning of imported and domestically-produced wheat that addresses supplier selection, order planning, transportation, storage, and distribution problems at the same time. Specifically, this model focuses on the wheat quality and wheat sleep period. Moreover, differentiation of long-term and short-term storage facilities and consideration of intra-layer flows between storage facilities are other characteristics of this model. A fuzzy chance-constrained programming approach is employed to cope with the uncertainties associated with domestic supply, demand, and global wheat prices. Applicability and advantages of the developed model are demonstrated using real data from the wheat supply chain of Iran. Results show that the current status of the wheat supply chain of Iran is far from being optimal, and there are many opportunities for improvement.

ASSESSMNET OF INTEGRITY OF PROTECTIVE BARRIERS OF LONG-TERM STORAGE FACILITY OF BN -350 REACTOR FACILITY

One of the ways of long-term handling spent nuclear fuel is storage of spent nuclear fuel in containers. For the purpose of complex radiological assessment and to make long-term prediction estimates of radiological situation possible at the territory of spent nuclear fuel storage facility the control over emanation of radioactive gases into atmosphere should be provided. Gaseous wastes are one a kind of radioactive wastes resulting from operation of nuclear energy and industry facilities. And increase in their concentration in the air indicate radioactive wastes from nuclear power plants or medical institutions, nuclear accidents and explosions and also of radiation accidents, that can include seal failure of spent nuclear fuel storage containers. Gaseous radioactive wastes include gases, containing 41Ar, 135Xe, 85Kr, 131I, 3Н, 14С and other radionuclides, that can often be formed and enter air environment in amounts, exceeding the levels determined by the norms of radiation safety. This paper provides results of researches of volumetric activity of gases in the air at the territory of spent nuclear fuel long-term storage facility of BN-350 reactor facility.

The Sandy Desilication Product Process Concept

Reactive silica is the most detrimental impurity in bauxite. When bauxite is contacted with Bayer liquor, reactive silica dissolves and then precipitates as a sodium aluminum silicate known as the desilication product (DSP), which is discarded along with the bauxite residue and maintained in long-term storage facilities. DSP recycling using bauxite residue lime sinter-leach is prohibitively expensive due to the high energy requirement for heating as well as high investment costs. In the sandy desilication product process, DSP is coarsened by controlling the desilication conditions, which enables the DSP fraction of the residue to be concentrated by physical separations. The DSP concentrate can then be recycled by sinter-leaching, whereby sodium and aluminum are returned to the Bayer process, reducing the burden associated with bauxite residue and facilitating total residue treatment options. Results are presented herein demonstrating DSP particle enlargement by seeding the reaction and controlling the supersaturation.

An assessment of absorbed dose and radiation hazard index from soil around repository facility at Bukit Kledang, Perak, Malaysia

The process of natural decay of radionuclides that emit gamma rays can infect humans and other living things. In this study, soil samples were taken at various locations which have been identified around the Long Term Storage Facility (LTSF) in Bukit Kledang, Perak. In addition, the respective dose rates in the sampling sites were measured at 5cm and 1m above the ground using a survey meter with Geiger Muller (GM) detector. Soil samples were taken using a hand Auger and then brought back to the laboratory for sample prepreparation process. The measuring of radioactivity concentration in soil samples were carried out using gamma spectrometer counting system equipped with HPGe detector. The obtained results show, the radioactivity concentration ranged from 11.98 – 29.93 Bq/kg for Radium-226 (226Ra), 20.97 – 41.45 Bq/kg for Thorium-232 (232Th) and 5.73 – 59.41 Bq/kg for Potassium-40 (40K), with mean values of 20.83 ± 5.88 Bq/kg, 32.87 ± 5.88 Bq/kg and 21.50 ± 2.79 Bq/kg, respectively. To assess the radiological hazards of natural radioactivity, radium equivalent activity (Raeq), the rate of absorption dose (D), the annual effective dose and external hazard index (Hex) was calculated and compared to the world average values.

Antineutrino Monitoring of Spent Nuclear Fuel

Military and civilian applications of nuclear energy have left a significant amount of spent nuclear fuel over the past 70 years. Currently, in many countries world wide, the use of nuclear energy is on the rise. Therefore, the management of highly radioactive nuclear waste is a pressing issue. In this letter, we explore antineutrino detectors as a tool for monitoring and safeguarding nuclear waste material. We compute the flux and spectrum of antineutrinos emitted by spent nuclear fuel elements as a function of time, and we illustrate the usefulness of antineutrino detectors in several benchmark scenarios. In particular, we demonstrate how a measurement of the antineutrino flux can help to re-verify the contents of a dry storage cask in case the monitoring chain by conventional means gets disrupted. We then comment on the usefulness of antineutrino detectors at long-term storage facilities such as Yucca mountain. Finally, we put forward antineutrino detection as a tool in locating underground "hot spots" in contaminated areas such as the Hanford site in Washington state.

Analysis of Available Vessels and Storage Capacities in Case of Large Oil Spill in European Union with Particular Reference to Republic of Croatia

Considering the constant growth of maritime transport and the role of the European Union in the international seaborne trade, it is important to determine the readiness of the EU in case of marine pollution. This paper summarizes the data regarding the number of the vessels ready for the response, and immediate and long-term storage facilities for the oily waste collected after an operation on the European Union territory. The aim of the study is to show the current available operational capacities in each Member State, as well as to determine the strength and capacity of five European regions for a prompt and efficient response to an oil spill. This paper seeks to highlight the importance of practical details that should be accessible and well prepared when an oil spill occurs. Based on the analysis of secondary data, it was found out that the Mediterranean area has the largest number of vessels ready for response in case of oil pollution, while the largest storage capacity for oily waste on shore is in the Baltic region. Particular reference is given to the Republic of Croatia which currently has nine available response vessels with the total storage capacity on board of 49.7 m3.

Monitoring of spent nuclear fuel with antineutrino detectors

We put forward the possibility of employing antineutrino detectors in order to control the amounts of spent nuclear fuel in repositories or, alternatively, to precisely localize the underground sources of nuclear material. For instance, we discuss the applicability in determining a possible leakage of stored nuclear material which would aid in preventing environmental problems. The long-term storage facilities are also addressed.

The awareness and perception about the Ethical concerns related to the Biobanks among Medical and Dental practitioners- A questionnaire based study

Background: The term Biobank has been used in different ways but one way is to define it as an organized collection of human biological material and associated information stored for one or more research purposes. By definition, Biobank is a long-term storage and conservation facility for biological specimens, to support future scientific investigation. The aim of this study is to assess the awareness and perception of Biobanks, their existence, aims and objectives and the ethical concerns related to them, among the clinicians pertaining to both medical and dental specialties. Methods: A questionnaire comprising of 31 questions of which few are purely awareness and rest are perception based is framed. The questions which were framed for the questionnaire, have few of them given direct responses as YES, NO, DON'T KNOW and the remaining of them have been graded into LIKERT'S SCALE, ranging from 1 to 5. Statistical analysis: After obtaining the response, the answers were plotted in MS-Excel sheet and analysed statistically for the Percentages, Frequencies, Chi-square and degree of Association (p>0.05= No Association) between the two fraternities responses by using SPSS 22.0 version software. The p value was set at 0.05 Result: There was found a level of association between both the groups for certain sensitive questions relating to privacy of information and ownership claims. Conclusion: It can be concluded that the willingness to participate in sample donation, motivation for sample donation are in agreement with each other, which is worth being further investigated. DOI: 10.21276/AABS.1400