Results 1 - 10 of 625
Results 1 - 10 of 625. Search took: 0.029 seconds
|Sort by: date | relevance|
[en] The objective of the safety assessment was to evaluate the level of robustness and sufficiency of safety margins during exposure to extreme natural conditions (considering the facts of the accident at Fukushima Daiichi NPP), loss of power, loss of ultimate heat sink, and if the event has escalated into a severe accident. A detailed deterministic evaluation was performed to identify the level of defence in depth and the capability to fulfil the fundamental safety functions during the specific initiating events and design extension conditions regardless of extremely low probability of their occurrence. The evaluation was performed for all reactor (and spent fuel pool) operating modes and states, including the case if all site units were affected. The assessment confirmed for the majority of emergency scenarios that sufficient margins exist and barriers are robust enough to provide defence in depth both in the area of design and in the area of personnel, administrative and technical provisions for accident management. In spite of considerable robustness of barriers, it was concluded based on results of assessment that opportunities for further safety improvements exist with respect to highly improbable beyond design basis situations. The measures for safety improvements were included in the Post-Fukushima National Action Plan.
[en] In the last decades the use of satellite images and remote sensing for agricultural activities has increased to encompass factors such as plant growth or biomass. However, satellite images may not be available for all regions or during all seasons (cloud cover) and precision agriculture requires smaller resolutions for mapping small elements as for example trees or smaller crops. The application of multispectral cameras mounted on UAVs (Unmanned Aerial Vehicles) is therefore a new and fast developing market and methodology. In order to explore its opportunities a training course on the use of UAVs and multispectral camera systems in agriculture was organized for the staff of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture in Vienna, Seibersdorf from 23-27 September 2019. The course was led by Mr Erik de Badts (Micasense) but included several guest lecturers from different companies and research facilities. In total six staff members from the SWMCN laboratory and section participated. The course provided insights into the different UAVs available, camera systems, software and data processing programmes. IAEA staff learnt how to plan a UAV survey and process acquired data.
[en] The Federal Office for the Safety of Nuclear Waste Management (BfE) is the competent licensing authority for interim storage of spent nuclear fuel (SNF) and high-level radioactive waste (HLW) in Germany. The concept of dry interim storage comprises dual purpose casks (DPC) equipped with a double barrier lid system with permanent monitoring of its leak-tightness. Existing storage licences in Germany are limited to 40 years. Due to the time needed for site selection, licensing procedure, construction and commissioning of a deep geological repository (DGR), a prolongation of the interim storage period will be necessary to bridge the gap until final disposal. To demonstrate if safety requirements could be fulfilled by the transport and storage cask beyond the initially licensed 40 years additional research is required. Research towards material degradation e.g. ageing of cask materials or internals, fuel assembly behaviour and behaviour of storage facility buildings and operational equipment is the basis for the safety of prolonged SNF storage. To identify potential fields of further interest it is also necessary to acquire additional data for the above mentioned research. As interim storage facilities are a key step towards the final disposal, it is also necessary to conduct research towards the impact of prolonged interim storage on the final disposal, especially due to the increasing relevance of ageing effects like material degradation. This includes foremost data acquisition and storage as a prerequisite to enable a safety based choice of actions. Furthermore, as Germany is phasing out of nuclear energy, the knowledge management in the nuclear field gains enormous importance especially with regard to human resources. The BfE as licensing authority has initiated several research projects to cover the foresaid topics to be presented in this article. (author)
[en] The paper presents the main Russian concepts and projects in the field of spent nuclear fuel and high level liquid waste reprocessing. A new concept of partition was proposed to minimize waste requiring deep geological disposal. The key problems and tasks of the concept are discussed. (author)
[en] National decisions about the management of spent nuclear fuel have global consequences for safety, security, and nonproliferation. For the past four years, the Nuclear Threat Initiative (NTI) has been catalyzing a spent fuel management partnership in the Pacific Rim – East Asia, the United States and Canada – a region with more than 230 power reactors and 170,000+ tons of spent fuel as of 2018. In the last year, the Partnership has created three expert working groups to address specific technical and societal challenges identified by the participants in previous workshops. These are: (1) underground research facility research and development; (2) long-term monitored dry cask storage; and (3) technical and non-technical aspects of repository siting. The working groups will meet several times a year to fulfill their objectives and identify additional topics that would benefit from collaborative research and development. The paper: surveys the status of nuclear power generation, spent fuel accumulation and spent fuel disposal plans in the Pacific Rim; describes the security and nonproliferation implications of accumulating spent fuel stockpiles; details the efforts that led to the development of a Pacific Rim Spent Fuel Management Partnership and subsequent working groups; and discusses the research agendas of each working group. It is hoped that this Partnership will help provide solutions to practical problems faced by waste managers and can serve as a template for future similar cooperation in other parts of the world. (author)
[en] For the disposal, intermediate storage and transport of spent nuclear fuel a number of properties of each fuel assembly must be determined, both for operational and safeguards needs. Important examples of these parameters are decay power, multiplicity, burn-up (BU), initial enrichment (IE), cooling time (CT), completeness of fuel assemblies, weight, amount of fissile material and nuclide inventory. This is done through a combination of known fuel history, measurements and codes. In addition, the status of the fuel assemblies is necessary to characterize. Failed or damaged fuels must be identified prior to final disposal in order to treat them appropriately, as are other mechanical and chemical issues that may affect the handling in the system. The uncertainties of these determinations are crucial in the use of the parameters, and are judged to be fairly large at present. Particularly the uncertainly of the decay power has a direct relationship to the cost of any repository due to temperature requirements in the systems. These cost savings are potentially very high, in the order of billions of Euros. A thorough understanding of these issues also opens ways to optimize the facilities, for example economically and environmentally. Due to the large amount of fuel assemblies to be measured, high through-put and robustness of the methods and instruments are paramount, as is the capacity to make fast decisions made on the measurement results and codes. The status and future needs of development of instruments, basic fuel data and cross sections, and codes is discussed in the paper, and how this is done in various collaborations world-wide. Potential problems, such as errors in fuel data, uncertainties in basic nuclear data, uncertainty propagation, conflicting methods and results etc., is illustrated and discussed. An international effort to blindly test the capacity to calculate decay power on fuel history, led by SKB and in collaboration with NEA/OECD – with more than 25 participating organizations and groups, using most of the internationally available codes, is described. (author)
[en] Thirty years of watching attempts at implementation of a U.S. national strategy for high level waste management embodied in the Nuclear Waste Policy Act and its Amendments (of 1982 and 1987) from many vantage points have led to strong personal views on what has gone wrong with U.S. strategies. Instead of a repository open in 1998, the U.S. is still probably at least two decades away from opening a repository. My vantage points include management of the Los Alamos National Laboratory research programs for Yucca Mountain, years on the staff of the U.S. Senate, Commissioner of the Nuclear Regulatory Commission, and Assistant Secretary responsible for implementation of these strategies. In the talk, the stark differences between the path followed so far by the U.S. and the path recommended by the U.S. President's Blue Ribbon Commission on America's Nuclear Future will be discussed. (author)
[en] The NEOLANT group of companies offers comprehensive engineering and IT support for power generation industries, particularly in the nuclear and fossil fuel sectors. PIM technologies are among the IT solutions NEOLANT develops and implements in support of the life cycle management of power generation facilities. Modern engineering information technologies enable efficient change management and nuclear power unit configuration management, on the basis of a solution developed by NEOLANT NPP Units Decommissioning Database information system, which uses 3D engineering information models of nuclear power units (Figure V-1). The information system concept includes a nuclear power unit information model in form of an engineering data management system (Figure V2.) to collect and store engineering information and documents and interfaces on the basis of a 3D plant model (e.g. of a nuclear power plant, the Joint Institute for Nuclear Research, any other nuclear facility) to search for information and to display it
[en] The Chernobyl nuclear power plant accident resulted in an increase of radioactive contamination at a global level. Interim International Radionuclide Action Levels for Food (IRALF) were introduced in 1985. To avoid undesirable exposure to the public, Pakistan imposed maximum radionuclide contamination levels on food items. Measurements of various radionuclides in various imported and exported food items were carried out at an environmental laboratory with modern counting systems capable of detecting low levels of radionuclides. Since 1956, Pakistan has been benefiting from the use of nuclear related technologies for the advancement of agriculture, engineering, biology, and medicine. The Pakistan Atomic Energy Commission (PAEC) was established as a research institution and government authority focused on peaceful uses of nuclear technology. In 2001, the Pakistan Nuclear Regulatory Authority (PNRA) was established as an independent body for the regulation of nuclear safety, radiation protection, transport and waste safety in the country. The PAEC is responsible for design preparation and proper operational functions of commercial nuclear power plants. The safety regulations and protection of nuclear power facilities are managed by PNRA. Pakistan is in the process of building power plants with a capacity of ∼8800 MW by 2030. Under this policy, the Karachi Nuclear Power Plant (KANUPP) and Chashma Nuclear Power Plant (CHASHNUPP) have been expanded under PAEC and PNRA programmes. The Nuclear Institute for Food and Agriculture (NIFA) in Peshawar is a research institute under the PAEC and conducts research and development in the nuclear sciences related to food irradiation, crop production and protection, soil fertility, water management and conservation and adding value to food resources. In addition, the Food and Environmental Section at NIFA is working to assess radioactive contamination in water, soil and agricultural produce, and plan strategies in case of a nuclear accident. The Fukushima Daiichi accident in March 2011 did not directly affect land in Pakistan. However, Pakistan is designing strategies to deal with contaminated territory as part of emergency preparedness and planning. (author)
[en] This paper presents the results of TRANSURANUS code testing for modelling the Behaviour of WWER nuclear fuel in LOCA accident conditions. The code was tested using data of the IAEA Coordinated Research Project Fuel Modelling in Accident Conditions (FUMAC). Fuel pins of Westinghouse and TVEL design are currently relevant for Ukrainian NPPs. Fuel from both vendors is presented in the FUMAC project. A part of the experimental data (MTA-EK data, IFA 650.10, IFA 650.11 and Studsvik 192&198) was simulated at SSTC NRS. Some of these data sets and KIT QUENCH-L1 set were calculated by other teams using the TRANSURANUS code (INRNE, Bulgaria; JRC, Germany). TRANSURANUS code demonstrated good capabilities for predicting the Behaviour of nuclear fuel rod cladding. The predicted cladding geometry and time of burst for both general types of cladding (Westinghouse and TVEL) show good correlations with the experimental data for such regimes. In addition, experimental data of the FUMAC project contained the results of post irradiation measurements after operation in a commercial reactor. These data were used to test TRANSURANUS code capabilities for modelling the fuel rod Behaviour in the core under burnup. (author)