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[en] Degraded landscapes adjacent to gold tailing storage facilities (TSFs) typically suffer from loss of ecosystem function as a result of seepage pollution. Restoration of these areas has become a primary concern in the fields of environmental science and management within recent decades. To assess the extent of land degradation, detailed monitoring of pollution took place over a period of 4 years on farmland adjacent to a gold TSF in South Africa. The Landscape Function Analysis (LFA) monitoring procedure was developed by David Tongway for the Australian rangelands, and has been utilised in this investigation to assess the impact of seepage pollution on the soil within the aforementioned farmland area. This paper indicated that the LFA procedure could not accurately present landscape stability and ecosystem functionality at the seepage-polluted sites within the short monitoring period presented in this study. It was established that no adverse effects on the natural vegetation were apparent, other than encroachment by Seriphium plumosum, which affected the grazing quality of the area but contributed significantly to the LFA values.
[en] When radiopharmaceuticals are procured, it is tempting to select based on the cost of the product. In the case of Lutetium-177 for radiopharmaceutical therapy, this may have considerable practical consequences. The radionuclide can be produced using a direct (NCA Lu-177) or an indirect method (CA Lu-177), yielding products with different specific activities and different levels of contamination with Lu-177m, which has a half-life of 160 days. We asked ourselves what the implications for waste management would be if we switched from NCA to CA Lu-177. Data from 73 Lu-177 therapy doses prepared and dispensed in our hospital were reviewed. Doses were individually prepared, starting with approximately 7.4 GBq Lu-177. The activity of waste from the radiosynthesis procedure (production waste, P) and from dispensing and administration of the patient dose (dispensing waste, D) were calculated. These values were used to estimate potential levels of Lu-177m in waste. Waste P contained an average of 885 ± 336 MBq and waste D 183 ± 106 MBq Lu-177. Assuming that 0.05 kBq Lu-177m is present per 1 MBq CA Lu-177 (Bakker et al, 2006), the waste contents of the longer-living isotope would be 44 kBq and 9 kBq respectively (Table 1). In South Africa, radioactive substances with activities less than 100 Bq/g and total activity less than 4 kBq can be disposed as normal waste. On the day of synthesis and administration, all our production waste would have exceeded the 4 kBq limit, while only 10 lots of dispensing waste would fall below that level. In our worst-case scenario, even if a facility were to receive a ready-to-use Lu-177 radiopharmaceutical containing Lu-177m, waste from dispensing may have to be stored almost 2 years before disposal. In this study we only considered waste and we excluded patient excreta. For radiosynthesis and therapy, other aspects of the radionuclide, like the effect of low specific activity, should also be carefully considered. In conclusion, the decision regarding Lu-177 procurement should not be based on cost only. If long-living contaminants are likely in a radiopharmaceutical product, waste management and storage facilities will be an important consideration. (author)
[en] Nuclear Engineering Seibersdorf Ltd. (NES) performed decommissioning of an old waste storage facility, the so called 'bunker', which was commissioned in 1968 and used until 1978 for the storage of radioactive waste from medical, industrial and research activities, as well as from the operation of the Austrian research reactor ASTRA. Due to the layout of the bunker the initial decommissioning plan was to decontaminate the inner walls of the caverns and afterwards perform clearance measurements on the standing structure. However, throughout the first phase of decommissioning it turned out, that contaminations penetrated deeper into the concrete structure as initially anticipated, which made an adoption of the decommissioning strategy necessary. By changing the workflow and to remove non-contaminated parts of the structure first, also the strategy for the clearance measurements had to be adapted. The selective decommissioning strategy and the demand that measurements shall be performed by an accredited body, required to set up an adequate communication structure to keep the workflow going. Moreover, a fast communication between NES, the competent authority and the authority's (external) experts was necessary to receive clearance licenses on time, and to prevent backlog of dismantled material. The paper reports on the initial and the adapted decommissioning strategy and the challenges within the changed approach. Applied decontamination and decommissioning methods and the implemented radiation protection measures will be discussed. Furthermore, information on the methodologies for clearance measurements, the collaboration of the accredited body with the decommissioning team, as well as on the communication between NES and the competent authority will be given. Finally, a balance of radioactive waste vs. conventionally disposed waste will be shown. (authors)
[en] The main function of the Transfer Channel-interim Storage for Spent Fuel (TC-ISFSF) is to store the Nuclear Fuel from RSG GAS. Currently TC-ISFSF save spent fuel as much as 245 pieces. Therefore, all equipment systems must operate at safe operating limits. Especially the power supply system, air system, cooling system, and others. To maintain this condition requires effective maintenance, especially the availability of tools, materials, spare parts, and professional human resources in the field. Since most TC-ISFSF equipment is over 25 years of age, its performance will decrease as a result of the aging process. Therefore, the optimization of the operation should be done so that the result is still in operating condition but still consider the condition of the safe equipment. By optimizing the operation of TC-ISFSF facilities, it is expected that the management and storage of spent nuclear fuel will temporarily continue to sustain and ultimately support the safe use of nuclear technology. (author)
[en] According to the Swiss waste management policy, spent nuclear fuel is planned to be disposed in a deep underground repository. Prior to final disposal, spent nuclear fuel is stored at reactor sites and in a centralized dry storage facility. Since the operation dates of the final repository are unknown, extended periods of interim storage have to be considered. A research program to investigate the fuel rod integrity during long-term dry storage has recently been launched at Paul Scherrer Institute. In the context of the project, fuel rod performance simulations will be carried out with the code Falcon. Until now, an extensive literature survey concerning current trends in dry storage modelling has been written and first developments of Falcon's capabilities towards dry storage modeling have been made. In this work, Falcon has been modified by implementing a long-term cladding creep model. The original and upgraded versions of Falcon have been used to simulate a demonstration case consisting of the base irradiation, wet storage, drying and dry storage. Results obtained with both versions have shown an important difference in the cladding hoop creep which justifies implementation of the new creep model.
[en] This paper describes a preliminary study of the use of hydrogen peroxide as a biocide in wet storage facilities for aluminum-clad spent fuel elements. Aluminum Alloy AA6061 specimens were tested in 0.001 M chloride solution with addition of either 0.0015M or 0,0030M hydrogen peroxide. Immersion tests as well as anodic polarization tests were carried out in order to study the AA6061 behavior in hydrogen peroxide in the presence of diluted chloride solution. The results show that a concentration of 0.0015M hydrogen peroxide solution would be safe to use in a storage site even in the presence of 0.001M chloride, since it does not cause any damage different from that caused by the chloride. (author)
[en] TC-ISSF is a storage installation in wet storage type (wet storage). Conductivity, pH, temperature and level of pond water are important monitoring parameters related to safety aspects of TC-ISSF operation. Pool water management undertaken to ensure the operating conditions of TC-ISSF meet the requirements for normal operation listed in the Safety Analysis Report (SAR) and is one of the surveillance requirements of TC-/ISSF facilities. The pool water management activities are conducted through daily monitoring with recording of operating parameters in including conductivity, pH, temperature, and water level of the pond and the quality control of the make up water that is filled into the pond. Currently the TC-ISSF stores 245 bundles of BBNB, while the capacity of TC-ISSF is 1458 bundles. The result of monitoring obtained maximum conductivity value is 1.53 μS/cm, in accordance with the requirement of normal operating limit conditions which set the conductivity value should not be more than 15 μS/cm. The pH value of pond water ranges from 5.73 to 6.39, in accordance with the requirements of normal operating limits of 5.5-7.5. Water temperature of ponds average 27.15 °C with a maximum value of 28.04 °C, in accordance with the requirements of the normal operating limit conditions of a maximum of 35 °C. Pond water depth ranges from 6.23 - 6.38 m, in accordance with the requirements of the normal operating limit condition with a minimum water level of 3.6 From the surface of BBNB (water level 5,96 m). The control of the demineralized water quality that is filled into the pond (make up water) is done by maintaining the lowest possible conductivity that is reached at an average of 0.6 μS/cm and in the pH range of 5.5-7. The purpose of this activity is to obtain operating data of interim storage for nuclear spent fuel and ensure the parameters of the operation in accordance with the conditions boundary conditions for normal operation as one of the aspects of safety of TC-ISSF operation. The results of this evaluation are also useful as one of the important data to assess the aging of storage facilities while temporary nuclear fuel. (author)
[en] The French natural gas transmission network offers several entry and exit points (cross-border interconnections, LNG terminals, underground storage facilities), giving its users a choice between various supply combinations. Since 1 November 2018, the TRF has become the new contractual framework for the French transmission network. It is built to a model that combines judicious investments in terms of infrastructure with contractual mechanisms which facilitate the management of the network's residual bottlenecks. A balanced supply management is required for the smooth running of the gas system in winter. The French operators, GRTgaz and Terega, must ensure the safety, efficiency and balance coverage of their networks at all times. In accordance with their obligations, the GRTgaz and Terega networks must have the necessary infrastructures to assure continuity in the transportation of gas, including in the event of a so-called P2 cold peak. In this context, GRTgaz and Terega produce an annual Winter Outlook in order to verify compliance with these obligations and share their analysis of the coming winter with the market. The Winter Outlook is an exercise that makes it possible to assess the balance coverage for the French zone and downstream of the network bottlenecks for different gas demand scenarios and supply schemes. The Winter Outlook 2019-2020 is the 2. edition to be published that incorporates the provisions made as part of the creation of the TRF on 1 November 2018.
[en] The Department of Energy (DOE) is planning for future large-scale transport of commercial Spent Nuclear Fuel (SNF) and High-Level Radioactive Waste (HLW) to eventual disposal and/or storage facilities. Various options for procuring transportation services are being evaluated. To inform this work, a review of past comments received on DOE transportation acquisition activities in the early 1990's through 2016 was conducted. Through the course of data collection, staff analyzed comments submitted from ten DOE initiatives from DoE's Office of Civilian Radioactive Waste Management (OCRWM) and DoE's Office of Nuclear Energy (DOE-NE). This paper summarizes and outlines key themes arising from these comments. Past issues identified by a wide variety of commenters (nuclear industry and cask vendors, nuclear utilities and purchasers, states, Tribes, local governments, rail carriers, nongovernmental organizations, trade organizations, engineering firms, and members of the public) were examined. These issues concerned DoE's activities to make maximum use of the private sector to transport and store SNF and HLW. The key themes analyzed include: Uniqueness of the Shipping Campaign, Views on Privatization, Industry Risk and Privatization, Unclear Roles and Responsibilities, and Responsibilities Recommended for DOE to Maintain. This paper concludes by discussing lessons that can be learned from analyzing these public comments and what that may mean moving forward in the U.S. radioactive waste management program. (authors)
[en] The French natural gas transmission network offers several entry and exit points (cross-border interconnections, LNG terminals, underground storage facilities), giving its users a choice between various supply combinations. Since 1 November 2018, the TRF has become the contractual framework for the French transmission network. It is built to a model that combines judicious investments in terms of infrastructure with contractual mechanisms which facilitate the management of the network's residual bottlenecks. A balanced supply management is required for the smooth running of the gas system in winter. The French operators, GRTgaz and Terega, must ensure the safety, efficiency and balance coverage of their networks at all times. In accordance with their obligations, the GRTgaz and Terega networks must have the necessary infrastructures to assure continuity in the transportation of gas, including in the event of a so-called P2 cold peak. In this context, in accordance with the Energy Code, art. L141-10, GRTgaz and Terega produce an annual Winter Outlook in order to verify compliance with these obligations and share their analysis of the coming winter with the market. The Winter Outlook is an exercise that makes it possible to assess the balance coverage for the French zone and downstream of the network bottlenecks for different gas demand scenarios and supply schemes. The Winter Outlook 2020-2021 is the 3. edition to be published that incorporates the provisions made as part of the creation of the TRF on 1 November 2018.