Results 1 - 10 of 38010
Results 1 - 10 of 38010. Search took: 0.04 seconds
|Sort by: date | relevance|
[en] If in the 19th century scientific knowledge moved from a generalist perspective to a growing specialization, in recent decades, problems that transcend disciplinary and political boundaries have required solutions based on interdisciplinary research and global actions, which led to the establishment of the Sustainable Development Goals (SDGs). Viewing from the latter perspective, the study of ecosystem services has converged on a fast-growing, transdisciplinary area of knowledge, at the same time that the advances in the nuclear field have enabled applications in industry, health, agriculture and the environment. Considering the development of these two areas of knowledge, the objective of this study is to evaluate the correlation between Ecosystem Services (ES) and Nuclear Science and Technology (NST), by means of category building and content analysis applied to articles compiled from Web of Science. From 1980 to June 2020, 27,301 records (articles and reviews) were listed for the term 'Ecosystem Service*'. When refining the result with the application of descriptors related to the nuclear field, correspondences were found for 'Uranium'=14; 'Nuclear Power'=6; 'Nuclear Energy'=3; 'Nuclear Technology*'=1; 'Nuclear Fuel*'=1; 'Nuclear Material*'=1; 'Radiation'=7; 'Isotope*'=188, totalizing 221 correspondences. On the other hand, 9,949 records were obtained for the same time interval, when using the descriptors for the nuclear field, plus the terms 'Nature' or 'Ecosystem*' or 'Environment'. Despite attesting that NST truly converges on ES, this correlation needs to be made more explicit in ES studies, in order to expand the perspectives for the conservation, preservation and recovery of the ecosystem services and their contribution to human well-being. (author)
[en] In air quality studies, atmospheric models are widely used in order to estimate the concentration and behavior of the spatial distribution of pollutants released into the atmosphere originated from point sources. The data derived from the Climatological Norms constitute an important reference for these studies, as they provide understandings for phenomena and events related to meteorological and climatic parameters, such as rainfall variability, deviations and temperature anomalies, dispersion of airborne pollutants, etc. In this article, the main objective is to validate the data of the meteorological station of the Center for the Development of Nuclear Technology (CDTN) for the time period of 1997-2017, comparing it to the normal climatology of INMET (National Institute of Meteorology) for the period 1981-2010. Based on the results, the variables humidity, wind, temperature and precipitation, obtained from the provisional climatological normals of the (CDTN), were assessed, in order to highlight the practical importance of local climatology for nuclear research centers. (author)
[en] A primary goal of the IAEA’s activities relating to reference products for science and trade is to assist Member States in the use of stable isotope and radioisotope analytical techniques to understand, monitor and protect the environment. Through its Environment Laboratories, the IAEA provides reference materials to laboratories as a key measure for calibration and quality assurance worldwide. The Terrestrial Environment Laboratory, part of the IAEA Environment Laboratories, provides assistance to Member State laboratories in maintaining and improving the reliability of analytical measurement results, in carrying out stable isotope analysis, and in assessing environmental level radionuclides and trace elements. In the field of stable isotope ratio analysis, the Terrestrial Environment Laboratory provides more than forty different reference materials for various applications covering mainly the stable isotopes of hydrogen, carbon, nitrogen, oxygen and sulphur. In all ecosystems, water supports all life functions. Understanding the details of its origin, availability, behaviour and movement is of the utmost importance for understanding these ecosystems . The use of stable isotopes as tracers of water origin and of its possible vulnerability to pollution is of primary importance for many scientific studies. The reliability and comparability of the analyses performed by laboratories in this context are crucial for a meaningful interpretation of any sample data, for management of the environment, and for taking decisions on policy or at an administrative level. Comparability of measurement results can be achieved only when the results are traceable to conventionally agreed standards, such as to the established δ-value scales and the corresponding reference materials for relative stable isotope ratio measurements. The IAEA has supported such scientific investigations since the 1960s by providing basic support through analytical networks like the Global Network of Isotopes in Precipitation and associated databases, and in its international role of providing reference materials for stable isotope measurement and calibration in laboratories worldwide. As custodian of the isotope measurement scales and their realization by primary reference materials, the IAEA has a fundamental role in the application of such methods worldwide. The two most important reference materials produced by the IAEA are VSMOW2 (Vienna Standard Mean Ocean Water 2) and SLAP2 (Standard Light Antarctic Precipitation 2), which are used to realize the δ-value scales. Further quality control materials are used by laboratories to verify proper calibration with these two materials. This publication describes the production of the certified reference material GRESP (Greenland Summit Precipitation) for use as a quality control material. The reference material GRESP was produced following the applicable international ISO standards and characterized by laboratories with demonstrated competence.
[en] The SSDL of Latvia was established from 2000 to 2001 with the financial and technical support of the IAEA. In 2002 it became a member of the IAEA/WHO SSDL network. The SSDL facilities are in Salaspils, just outside Riga, the capital of Latvia, on the territory of the former nuclear research reactor. The SSDL is part of a LEGMC Laboratory. Currently SSDL has 5 specialists (including head of Laboratory and quality manager) that are highly qualified and experienced professionals in the field of calibration and testing of ionizing radiation measuring and monitoring devices. There is Internal Quality Assurance system implemented in SSDL to guarantee required precision and accuracy of measurement results. The quality of services provided by the SSDL is ensured by a regular participation in international comparison measurements. The laboratory irradiators include the PANTAK PMC-1000 X ray irradiation unit (40 kV to 225 kV), as well as the gamma irradiators OB-2 (Co-60, 3.7GBq), OB-6 (Cs-137, 740 GBq) and panoramic gamma irradiator OB-34 (with four Cs-137 and three Co-60 sources) for the calibration and testing of protection and diagnostic radiology dosimeters and measuring devices.
[en] Open-Cycle Cooling Water (OCCW) System of Qinshan Nuclear Power Plant (QNPP) was designed to supply sea water as the cooling water for heat exchangers of component cooling water system and emergency diesel generator (EDG) cooling water system. The main ageing mechanism of OCCW components with the environment of sea water includes corrosion, erosion, bio-fouling, aggressive chemical attack and sediment deposition, which would induce blocking, protective liner failure, corrosion perforation, reduction of heat transfer capability and jeopardize the safety and economical operation of plant. In order to reduce the risk of ageing degradation in OCCW system during the period of extended operating, the paper identifies the potential ageing degradation mode for OCCW components in QNPP, analyzes the insufficiency of the previous management measure, and investigated the coping strategy for each ageing degradation. Finally, the ageing management improvements of OCCW components are provided that include biocide treatment, system flow testing, disassembling inspection for critical equipment and heat transfer capability monitoring for safety important heat exchanger. These improvements have been applied in QNPP and proved effective in managing the ageing degradation of OCCW system. (author)
[en] Contents: ALFRED, Implementation process; Development of Licensing Support and RDI Infrastructure; Pre licensing and licensing elements; Stakeholders' involvement; Other elements; Conclusions - ALFRED project: Long term project, Major investment, International environment; Complexity of the authorization process; Experimental facilities for RD&Q, V&V, T&D; Stepwise approach in operational strategy; Dialogue with stakeholders started from the beginning; Crucial importance of the competence building; FALCON resources and EU expertise.
[en] Recent developments in the nuclear industry include stronger interest in extended plant operation and plans to shut down a number of nuclear power plants (NPPs) In the U.S., there is strong interest in extending NPP lifespans through subsequent license renewal (SLR) from 60 to 80 years. Extended plant operation and SLR raise a number of technical issues that may require further research to understand aging mechanisms. U.S. utilities and the U.S. Nuclear Regulatory Commission (NRC) have focused on the aging of systems, structures, and components and in particular four key SLR issues: reactor pressure vessel (RPV) embrittlement, irradiation-assisted stress corrosion cracking of reactor internals, concrete structures and containment degradation, and electrical cable qualification and condition assessment. Meanwhile, in recent years, a number of NPPs, both in the U.S. and internationally, have shut down or announced plans to shut down for various reasons, including economic, political, and technical challenges. Unlike in the past when there were very few plants shutting down, these new developments provide opportunities for harvesting components that were aged in representative light water reactor (LWR) environments. In a third related development, economic challenges and limited budgets have restricted the resources available to support new research, including harvesting programs. Given this constrained budget environment, aligning interests and leveraging with other organizations is important to allow maximum benefit and value for future research programs.
[en] Neutron Activation Analysis (NAA) is a well-established nondestructive analytic technique where the gamma radiation emitted by an irradiated sample is analyzed using an HPGe detector. The Neutron Activation Laboratory (LAN) of IPEN-CNEN/SP has been performing NAA analyses for over 30 years, and has plans of implementing quality control protocols to their analyses. In this sense, the environmental monitoring of the laboratories where the detectors are used has been performed for many years, in a manual way with no more than 2 measurements per day. In this work, an automated monitoring station based on a microcontroller ArduinoUNO board has been developed which comprises four thermo hygrometer sensors for monitoring different parts of the environment, plus a thermocouple for monitoring the inside of the liquid nitrogen dewar. The results obtained allow for a discussion on the performance and adequacy of the sensors. (author)
[en] This book proposes a glossary of about four hundred words related to climate and to its evolution, with explanations associated with the context of use of these words. Moreover, some notions are more particularly detailed such as: aerosols as climate polyvalent actors, ices as witnesses of ancient climates, the diversity of climates, the international action (COPs), the cryosphere as witness and actor of the present climate, the water cycle, the carbon present in Earth's envelopes, the greenhouse effect, El Nino, the IPCC, the measurement and evolution of ocean level, monsoons, the interest of satellite-based measurements, the interest of paleoclimates and of their reconstruction, some natural fluctuations of climate (Middle-Age optimum, the little ice age), and scenarios
[en] Radiological characterization is a key activity enabling planning and implementation of decommissioning of nuclear facilities. Effective characterization allows determining the extent, location and nature of contamination providing crucial information to facilitate facility dismantling, the management of material and arising waste, protection of workers, the public and environment as well as associated cost estimation. The Working Party on Decommissioning and Dismantling (WPDD) within the Nuclear Energy Agency (NEA) of OECD formed the Task Group on Radiological Characterization (TGRCD) to compile recent experience of NEA member countries in radiological characterization, including the experience of international experts and practitioners, the learning from international case studies and international conferences and national approaches to the application of international and national regulations, standards and guidance documents. The transition of a nuclear facility from operation to the implementation of dismantling is a critical phase in every decommissioning project. Several organizational and technical modifications are needed to adapt the facility to meet the new objectives and requirements. A variety of activities need to be planned and performed to support the transition and to prepare the dismantling of the facility. Experience has shown that it is essential to start with preparations for decommissioning at a very early stage, at best already during the design stage of the facility but at least during the operational stage. The preparation of the transition for decommissioning and dismantling (D&D) is a key issue for the success of the global D&D project to minimize delays and undue costs, to optimize personnel and other resources and to initiate preparatory activities for decommissioning in a planned, timely and cost-effective manner and thus to ensure safe and efficient decommissioning. With the growing number of nuclear facilities reaching the decommissioning stage WPDD formed the Task Group on Preparing for Decommissioning (TGPFD). This group of experts included regulators, nuclear operators and independent experts to review the strategic aspects to optimize the preparations for decommissioning from the last years of operation onwards. This paper gives and overview of the work carried out by both task groups and their respective findings. (author)