EU Clearinghouse on NPP OEF Summary Report on Fuel Related Events

Fuel performance and reliability, especially fuel integrity, is one of the important aspects of the safe operation of nuclear power plants. The fuel rod cladding surrounding the fuel pellets represents the first barrier to the release of radioactive fission products. Fuel integrity must be maintained during normal operation and expected transients, and fuel damage must be limited during postulated accidents. Over the years, a very significant effort has been put into analysing and understanding the causes of fuel failures, and important strategies in design, engineering, manufacture, inspection, operation and management have been developed to try to avoid them. The results of this effort are reflected in improvements regarding the use of new materials, a more robust design, new fabrication methods, more efficient inspections of newly built fuel assemblies, quality assurance and better operational strategies. More demanding operational conditions for the fuel, or singular interventions like system decontamination or fuel cleaning, have raised concerns about fuel performance. The result of these counteracting trends is that fuel performance has improved significantly over the years, but there are still some issues which need to be addressed, such as fretting, corrosion, fuel handling, and in storage events. Based on the fuel failure events reported to the IRS database operated by the NEA/IAEA, and on the work performed under the EU Clearinghouse on Nuclear Power Plant Operational Experience Feedback, this summary report lists the main causes of actual and potential nuclear fuel failures in three situations: in-core, during handling, and during storage. The report also includes the main recommendations to fuel designers and manufacturers, nuclear power plant operators and regulatory authorities to reduce the incidence of fuel related events, and a list of actions now widely and systematically applied in nuclear power plants that were originated by operational experience exchanges and now constitute a set of good actions that help reduce the number of reported fuel related events.JRC.DDG.F.5-Safety of present nuclear reactor

European Clearinghouse: Nuclear Power Plants Decommissioning Related Events

Decommissioning is the final phase in the life cycle of an installation. The term decommissioning refers to administrative and technical actions taken to allow removal of some or all of the regulatory controls from a nuclear facility. It is an integral process that involves complex and diverse operations as well as several stakeholders and regulatory organisations. Regardless of its complexity and its cost, suitable strategies and techniques for the decommissioning of nuclear power plants are available, and have been successfully applied in many sites. However, the operative experience could be better collected, and the lessons learned should be shared as their equivalents of the operational phase. This is a major issue considering the large number of NPP that are in this phase, or are close to their shutdown. This Summary Report presents the results of a study performed by the European Clearinghouse on Operating Experience Feedback of NPP about events related to decommissioning.JRC.F.5-Nuclear Reactor Safety Assessmen

European Clearinghouse: Report on External Hazard related events at NPPs

External phenomena are a significant source of hazards to nuclear power plant operation, and thus it is important to investigate the existing operational experience in this kind of events. The objective is to determine the adequacy of protection of nuclear power plants against external hazards and the effectiveness of corrective actions, as well as to provide recommendations on how to prevent or mitigate the impact of external phenomena on NPP operation. IAEA Safety Guide NS-G-1.5 defines external events as "events that originate either off the site or within the boundaries of the site but from sources that are not directly involved in the operational states of the nuclear power plant units, such as fuel depots or areas for the storage of hazardous materials handled during the construction, operation and decommissioning of units located at the same site". This Summary Report presents the results of a comprehensive study performed by the European Clearinghouse on Operating Experience Feedback of NPP with the support of IRSN and GRS. It addresses both natural origin and man-induced external events, with the exception of the earthquake hazard.JRC.F.5-Nuclear Reactor Safety Assessmen

Representing Black Male Innocence

The course is an elective of specialization that seeks to develop the general competence of innovative thinking and specific ABET competence (j.3) that lets you know and apply contemporary issues of supply chain aligned to industry trends that will allow you more dominance in the professional field of industrial engineering.SCM course is important because permit to student understand and apply models and best practices of logistics in Supply Chain. Different issues regarding to the logistics operations marketing procurement warehousing and information technology will be discussed and proposed. The results from strategies in Supply Chain collaborative and alliance 3PL order management and fulfillment and others key issues will be studied. The course concludes with trends and challenges for supply chain in the future

In Situ Thermal-Stage Fitted-STEM Characterization of Spherical-Shaped Co/MoS2_{2} Nanoparticles for Conversion of Heavy Crude Oils

We report the thermal stability of spherically shaped cobalt-promoted molybdenum disulfide (Co/MoS$_{2}$) nano-catalysts from in-situ heating under electron irradiation in the scanning transmission electron microscope (STEM) from room temperature to 550 °C ± 50 °C with aid of Fusion® holder (Protochip©, Inc.). The catalytic nanoparticles were synthesized via a hydrothermal method using sodium molybdate (Na$_{2}$MoO$_{4}$·2H$_{2}$O) with thioacetamide (CH$_{3}$CSNH$_{2}$) and cobalt chloride (CoCl$_{2}$) as promoter agent. The results indicate that the layered molybdenum disulfide structure with interplanar distance of ~0.62 nm remains stable even at temperatures of 550 °C, as observed in STEM mode. Subsequently, the samples were subjected to catalytic tests in a Robinson Mahoney Reactor using 30 g of Heavy Crude Oil (AGT-72) from the golden lane (Mexico’s east coast) at 50 atm using (ultrahigh purity) UHP hydrogen under 1000 rpm stirring at 350 °C for 8 h. It was found that there is no damage on the laminar stacking of Co/MoS2 with temperature, with interlayer spacing remaining at 0.62 nm; these sulfided catalytic materials led to aromatics rise of 22.65% and diminution of asphaltenes and resins by 15.87 and 3.53%, respectively

Advancing Implementation of Nuclear Decommissioning and Environmental Remediation Programmes

Significant progress has been achieved in recent years in terms of addressing the legacies from the early development of nuclear energy, including the decommissioning of redundant research and fuel cycle facilities, research reactors and power plants, and the remediation of sites affected by past uranium mining and processing operations. Some countries are moving forward with dealing with these legacies, and accordingly have built up appropriate technical resources and expertise, but many national programmes still face very significant challenges. However some factors constraining progress in addressing legacies from the past remain.There is for that reason a need to better understand the global situation and to analyse the barriers impeding the implementation of decommissioning and environmental remediation programmes, with the aim of outlining actions that may improve current situations where progress is impaired. The IAEA 'CIDER' project was launched in March 2013 in support of these objectives and with the support of other international organisations, particularly the European Commission and the European Bank for Reconstruction and Development. The present document aims to support the development of adequate policies in IAEA Member States for decommissioning and environmental remediation, addressing in essence the following three fundamental questions: - What are the motivations for implementing decommissioning and environmental remediation? - What are the main constraints hindering progress of decommissioning and environmental remediation programmes? - What are the solutions for overcoming these constraints, taking account of experience from programmes under implementation? This document, prepared in close collaboration with the IAEA, makes concise yet comprehensive proposals in answer to those questions, drawn from the results of a global survey performed in advance of the CIDER project and on the more extensive analysis provided in the CIDER project report, which was elaborated by expert groups from IAEA Member States.JRC.A.4-Nuclear Safety and Securit

Amplificador de Potencia Clase-S para Transmisor EER

A Class-S power amplifier for an EER transmitter is shown in this paper. Simulations and measurements on a circuit prototype are presented showing good agreement. The amplifier is based on MOSFET technology both for the power stage and driver. Pulse Width Modulation driving signal required by the amplifier is generated by means of a in-house designed DSP board. Up to 50W output peak power can be delivered to the RF power amplifier (Class-S amplifier load) at 86 % power-added efficiency while harmonic distortion is below 30 dBc and third order intermodulaction products remain well below 34 dBc

The Piezoresponse in WO₃ Thin Films Due to N₂-Filled Nanovoids Enrichment by Atom Probe Tomography

Tungsten trioxide (WO3) is a versatile n-type semiconductor with outstanding chromogenic properties highly used to fabricate sensors and electrochromic devices. We present a comprehensive experimental study related to piezoresponse with piezoelectric coefficient d33 = 35 pmV−1 on WO3 thin films ~200 nm deposited using RF-sputtering onto alumina (Al2O3) substrate with post-deposit annealing treatment of 400 °C in a 3% H2/N2-forming gas environment. X-ray diffraction (XRD) confirms a mixture of orthorhombic and tetragonal phases of WO3 with domains with different polarization orientations and hysteresis behavior as observed by piezoresponse force microscopy (PFM). Furthermore, using atom probe tomography (APT), the microstructure reveals the formation of N2-filled nanovoids that acts as strain centers producing a local deformation of the WO3 lattice into a non-centrosymmetric structure, which is related to piezoresponse observations