From initial treatment design to final disposal of chelating agents: a review of corrosion and degradation mechanisms

In this review, we discuss how chelating agents and their products can cause corrosion and how it goes through the oilfield cycle including thermal, photo, and biodegradation.

Pemberdayaan Masyarakat Melalui Pemanfaatan Sampah Anorganik Menjadi Produk Kerajinan yang Bernilai Ekonomis

Inorganic waste is a type of waste that is difficult to decompose naturally by microorganisms. Inorganic waste processing is carried out by collecting, disposing and transporting it to the final disposal site (TPA). There needs to be an effort to utilize inorganic waste, especially plastics, into useful products. People in Limbungan Village, Rumbai Pesisir District, Pekanbaru City already have a waste bank, but the benefits have not been felt by the community because inorganic waste is still being disposed of. There is a need for efforts to socialize and educate the public to process inorganic waste into handicraft products that have economic value. The method is carried out by educating the public about waste processing in general and demonstrating the use of plastic waste into handicraft products. After the counseling was carried out, the community had knowledge about waste management in general and skills in processing plastic waste into handicraft products such as bags, candy containers that were suitable for use and worthy of sale

Material and Energy Recovery from the Final Disposal of Organic Waste

While receiving nearly 10,000 times the energy that we presently need from the Sun, almost 600 EJ/a, developed and developing countries continue to mostly use fossil fuels even though the technologies available and the adaptation of individual and collective behaviours could make it possible to use only solar energy [...]

PROJETO DE REATOR ANAERÓBIO DE FLUXO ASCENDENTE (RAFA) PARA TRATAMENTO DE VINHAÇA

Brazil is the largest sugar and alcohol producer in the world, consequently, it is also a major vinasse producer, which is a problem, as it has a high potential for pollution, severely impacting the soil and water, despite being used in fertigation of cane fields. When treated in anaerobic conditions, however, it can produce energy and be used as a biofertilizer for the soil. This treatment can be performed by an Upflow Anaerobic Sludge Blanket (UASB), considered efficient by the literature. Based on this, this article tries to gather equations and collect data, reviewing the scientific literature with the objective of designing an UASB for the treatment of vinasse, exposing an alternative of suitable final disposal for this by-product. The results show good opportunities, with a great potential for reducing BOD and COD and producing biogas, electricity and biofertilizer, in addition to providing a compilation of equations and important data for future calculations.

Assistance in Processing Household Plastic Waste into Ecobricks at Medas Harmony Housing, West Lombok

Household waste contributes to the volume of waste. In general, household waste is easily biodegradable and difficult to decompose. Household products that are hard to decompose are generally plastic and plastic bottles predominantly. The difficulty of decomposing household plastic waste requires serious handling, so it is necessary to provide assistance for processing plastic waste into useful creations. One of them becomes ecobric. There are two methods of this activity, namely direct counseling and training. The results obtained after the community service activities were completed was that they were able to improve community skills in processing plastic waste into ecobrics. Furthermore, ecobrics are created into potted plants and other forms of creation. In addition, after this activity is carried out, it can reduce the movement of plastic waste to the final disposal site (TPA), so that the community hopes that this activity will continue to be transmitted to other places to create a clean and free environment from plastic waste.

On the temperature in a final disposal site for high-level radioactive waste

The Site Selection Act stipulates a precautionary temperature limit of 100 ∘C on the outer surface of the containers with high-level radioactive waste (HLRW) in the final disposal site. This precautionary temperature limit should be applied in preliminary safety analyses provided that the maximum physically possible temperatures in the respective host rocks have not yet been determined due to pending research. Increasing temperatures in the deep geological underground, caused by the heat generation of the HLRW, can trigger thermal, hydraulic, mechanical, chemical and biological processes (THMCB) in the respective host rocks of a final disposal site and thus endanger safety. Furthermore, high temperatures may hamper the feasibility to retrieve and recover HLRW from a final disposal site. Such processes are described in detail in databases for features, events and processes (FEP) databases. Single components or barriers of a final disposal facility may require specific design temperatures for the preservation of their features once a concept for long-term safety of a final disposal site is established; however, the interactions of all relevant processes of a concept for a final disposal site must be considered when a specific temperature limit for the outer surface of the containers is derived. This temperature limit may vary for particular safety and final disposal concepts in the host rock: salt, clay and crystalline rock. The conclusion is that temperature limits regarding the outer surface of the containers should be derived specifically for each safety and disposal concept and should be supported by a solid safety analysis. Temperature limits without reference to specific safety concepts or the particular design of the final disposal site likely narrow down the possibilities for optimisation and could adversely affect the site selection process in finding the best suitable site.

International safeguards for the final disposal of spent nuclear fuel – why, what and how

The objectives of international safeguards are the timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons (or for other purposes), and deterrence of such diversion by the risk of early detection for states with comprehensive safeguards agreements with the International Atomic Energy Agency (IAEA). Following these objectives, several studies have focused on the developments of concepts and methods for safeguarding final disposal facilities as well as on identifying the most feasible technologies that could potentially be deployed for verifying final disposal programmes (IAEA, 1998, 2010, 2018). These activities were coordinated through Member State Safeguards Support Programmes, including the joint tasks on the development of “Safeguards for Geological Repositories” (SAGOR, 1994–2004) and on the “Application of Safeguards to Geological Repositories” (ASTOR, 2005–2017). SAGOR performed a diversion path analysis for spent fuel disposal facilities, determined safeguards technical objectives and identified potential safeguards measures to meet those objectives. ASTOR supported the IAEA in assessing how safeguards measures could be effectively implemented and provided recommendations with respect to developing such measures. Specific verification technologies were developed under other Member State Support Programme tasks. A summary report on the progress and status of safeguards for spent fuel encapsulation plants and geological repositories was completed by ASTOR in 2017. ASTOR also identified areas and actions that need to be accomplished to support safeguards implementation in final disposal facilities, such as (1) establish performance requirements for the design of safeguards technologies relevant to geological disposal of spent fuel, (2) determine specific information needs of states and operators regarding safeguards implementation for geological disposal of spent fuel and develop appropriate guidance, (3) determine specific information needs of IAEA inspectors and analysts and develop a guidance document that provides recommendations for implementing safeguards for a geological repository system under the state-level concept and (4) develop and test appropriate safeguards equipment (IAEA, 2017; Moran et al., 2018). While several measures and technologies related to verifying the geological disposal of spent fuel have been used by the IAEA at other facilities or are in development or testing, other technologies still need to be developed and tested. In addition, ASTOR identified the need for approaches to how information about disposed spent fuel and high-level nuclear waste should be managed, handled, organized, archived, read, interpreted and secured for the long term (for centuries after repository closure and beyond), including an international standard for states and facility operators on information management, data-retention methods and timescales for preserving safeguards data for geological repositories. The presentation will introduce the objectives of international nuclear material safeguards for the final disposal of spent nuclear fuel, highlight the current status of developments and discussions in terms of approaches and technologies for safeguarding geological repositories, and give an outlook on implementing safeguards for final disposal in Germany.

Structural integrity investigations of spent nuclear fuel with finite element modeling

Radioactive waste in Switzerland will be disposed of in a deep geological repository (DGR). Responsible for the planning and preparation of realization of this task is National Cooperative for the Disposal of Radioactive Waste (Nagra). Spent fuel assemblies (SFA) constitute the main high-level waste (HLW) stream that will be disposed in the DGR. Prior to final disposal they will be transferred or transported to an encapsulation plant, where they will be loaded into final disposal canisters. To ensure that the structural integrity of SFAs is not compromised during handling and transportation, it is desirable to characterize the expected mechanical parameters of SFAs after long-term interim storage. Experimental research activities performed at the JRC Karlsruhe include safety aspects of radioactive waste management, encompassing also spent fuel storage and spent fuel/HLW disposal activities. Nagra and JRC have established a collaboration to jointly study relevant properties and behaviours of spent fuel rods, with the support of the Gösgen nuclear power plant and of Framatome, and in collaboration with other partners in Europe and internationally. As part of this collaboration, 3-point bending and impact tests were performed at the hot-cell facilities of JRC Karlsruhe, to determine the mechanical response of spent fuel rodlets under quasi-static and dynamic loads. The structural integrity of fuel rods was also evaluated under different handling scenarios using finite element (FE) analysis. Starting with the construction of a static 3D FE model of a Pressurized Water Reactor (PWR) nuclear fuel rodlet in ANSYS Mechanical, Nagra has developed a series of FE models over the years. Mechanical properties of the original rodlet model were derived through an extensive validation process, using experimental data from the 3-point bending tests. To evaluate the mechanical response of an SFA in different loading scenarios, this model was expanded using 1D beam modeling approach. The development of the simplified 1D models is shown in this presentation. In particular, the effect of the contact formulation between the spacer grid and the rods is discussed. Finally, preliminary results of the bending response of a 15×15 PWR SFA sub-model are presented.

Management of high-level radioactive waste in Germany: roads from storage towards disposal – need and options for action

The road towards final disposal of high-level radioactive waste (HAW) produced in Germany requires extensive and foresighted management. To date, HAW has been stored in dual-purpose casks inside 15 interim storage facilities. Finally, it is disposed of in a deep geological repository. A site-selection process for this repository, taking into account the whole national territory, started in 2017. The road from interim storage to final disposal is not yet planned in detail: neither temporally nor spatially nor technically. Important parameters are still unknown. The last operating licenses of the existing interim storage facilities, originally built to last for up to 40 years, will end in 2047, and a concept for prolonged interim storage does not exist. The dates for the decision on the repository site and the start of its operation are plagued by uncertainties, as well as the development of safety concepts for different potential host rocks or knowledge on the long-time behavior of disused fuel assemblies during dry interim storage. According to the German site-selection law (Deutscher Bundestag, 2017) the siting decision for the final repository is planned to be made in 2031; Thomauske and Kudla (2016) drew up timelines for the site-selection process to end between 2059 and 2096. The research project WERA – Management of high-level radioactive waste in Germany: Roads from storage towards disposal – addressed these uncertainties through the development of different design options for the four main steps of the German road to disposal and of a variety of scenarios combining these steps, covering a broad range of potential future designs of the road to disposal. These scenarios have been analyzed in detail. Need for technical and political action along the road to final disposal has been identified. Options for action were named, and their preconditions and consequences were listed. The design options and the scenarios derived form the basis of societal discourse on the disposal of high-level radioactive waste. Thus, the research project WERA contributes toward the politically and societally active integration of the different disposal steps (interim storage, receiving storage facility, waste conditioning, and final disposal).