Rigorous Safety Requirements Research Articles

Realistic performance assessment of FeCrAl-UN/U3Si2 accident tolerant fuel under loss-of-coolant accident scenario

The rigorous safety requirements in the nuclear industry have necessitated the development of accident tolerant fuels, with FeCrAl-UN/U3Si2 being one of the latest innovations in this field. To comprehensively evaluate the performance of this fuel type under accident scenarios, the best estimate plus uncertainty method is employed to conduct a realistic safety assessment of a large break loss-of-coolant accident in the HPR-1000 nuclear power plant using FeCrAl-UN/U3Si2 fuel. The peak cladding temperature and peak pellet temperature are selected as figures of merit, while the uncertainties of key performance models for the FeCrAl cladding and UN/U3Si2 pellet are quantified. The upper tolerance limits of the two figures of merit are determined through uncertainty propagation calculations, and the key influencing parameters are also identified based on the sensitivity analysis. Results demonstrate that the FeCrAl-UN/U3Si2 fuel type owns larger safety margin than the conventional Zr-UO2 fuel type and effectively reduces the cladding temperature while significantly reducing oxidation and hydrogen production during the accident.

Energetic Characterization of Trim Cut Process Signals in Wire EDM

Wire EDM has a high potential for aerospace applications. Particularly the turbine manufacturing with its growing use of difficult to machine materials to meet the increasing demand for turbine efficiency is predestinated for a technology that is independent of mechanical material properties. However, rigorous safety requirements in aerospace necessitate the precise knowledge of thermal rim zone modifications induced by the process and its assessment regarding component (fatigue) strength. Therefore, insight into the effective specific energy dissipation as well as knowledge of external influences on the process is key for a broad application and certification of Wire EDM in turbine manufacture. This information can only be generated by analyzing the process signal during machining. The focus of these analyses should be set to the trim cuts during EDM because they define the resulting surface integrity of the part. However, the trim cuts’ high-frequent nature as well as their pronounced deviation from ideal EDM signal characteristics found in the literature makes energetic signal processing very challenging. In practice, varying machining heights as well as complex geometries cause deviations from the ideal process leading to a variance in geometrical or energetic values. Monitoring and evaluating the characteristic patterns of the process signals this paper aims to present a methodology to characterize different types of trim cuts energetically as a prerequisite for further correlations between process energy and rim zone formation.

Global nutrition problems and novel foods

Global nutrition problems and novel foods

Toward fulfilling the robotic farming vision: advances in sensors and controllers for agricultural applications

Real-time control is becoming an integral part of modern machine systems for high-quality agricultural production. Maintaining consistently high-quality agricultural production while keeping up with growing labor shortages is a challenge. Providing a workplace for labourers which meets increasingly rigorous safety requirements and environmental constraints is likewise a challenge. More appropriate energy management and soil management have also motivated real-time control applications. Appropriate sensing and control systems can reduce labor requirements, function in difficult environments, and allow vehicles to adapt to varying soil chemical and physical states. Labor shortages and environmental constraints coupled with the reality of spatial variability of chemical and physical properties among and within agricultural production areas readily explain the migration toward real-time control of agricultural equipment. This paper presents a review of the most recent advances in the development of sensors and controllers for agricultural applications.