European Methodology for Inspection Qualification - An Overview for the Non-specialist

The purpose of this document is to provide an overview of the European Network for Inspection and Qualification (ENIQ) Qualification Methodology and how the process of Inspection Qualification is commonly applied within Europe and elsewhere. It is intended as a reference source for a wide audience of engineers and technical staff such as safety engineers, stress analysts etc. who may not be routinely involved with either non-destructive examination or inspection qualification, but who may benefit from a greater understanding and appreciation of the ENIQ Qualification Methodology. It will also benefit those personnel who have a responsibility to provide practical assistance in the preparation of the qualification process.JRC.DDG.F.5-Safety of present nuclear reactor

Secagem de microalgas Scenedesmus acuminatus em leito de jorro: estudo experimental e de modelagem

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2016.A utilização de microalgas é crescente em diversas áreas de estudo por sua grande variedade e características. Neste contexto, a secagem é uma etapa importante na produção da biomassa de microalgas, pois permite a obtenção de um produto estável e estocável para posterior processamento. Com esta motivação, foi proposto um estudo acerca do processo de secagem da biomassa da espécie Scenedesmus acuminatus pela técnica de leito de jorro. Diferentes vazões de alimentação da biomassa (0,25, 0,45, 0,60 e 0,80 mL min-1) foram testadas com a temperatura do ar de secagem a 60 ºC. A modelagem fenomenológica e simulação foi realizada em um primeiro momento considerando os aspectos da fluidodinâmica do ar de secagem em estado estacionário. Em um segundo passo, adicionou-se de forma acoplada e transiente os fenômenos de transferência de calor e massa referentes à secagem. Os resultados experimentais permitiram avaliar a pertinência do modelo. Vários modelos de isotermas foram ajustados aos dados experimentais, sendo que o modelo que melhor representou esses dados foi de Oswin modificado, apresentando coeficiente de determinação igual a 0,989. A modelagem fenomenológica e simulação realizada reproduziram de forma adequada o comportamento obtido no estudo experimental, resultando nos perfis de velocidade, pressão, umidade e temperatura. Com os resultados experimentais e as simulações realizadas, nota-se que uma quantidade de sólido seco é sempre acumulada na câmara de secagem até que a alimentação seja encerrada. O produto final apresentou umidade média na faixa de 5,37 a 7,3 % em base seca que se situa na faixa permitida comercialmente. No âmbito das condições testadas, a alimentação de 0,80 mL min-1 gerou melhores desempenhos no secador, com eficiência da massa de sólido recuperado (58,27 %).Abstract : The use of microalgae is increasing in several study areas due to its great variety and characteristics. In this context, drying is an important step in the production of microalgae biomass, since it allows obtaining a stable product and storage for further processing. With this motivation, we propose a study of the drying process of microalgae Scenedesmus acuminatus by spouted bed technique. Different biomass feed flow rates (0.25, 0.45, 0.60 and 0.80 mL min-1) were tested with the temperature of the drying air at 60 °C. The phenomenological modeling and simulation was performed at first considering the aspects of fluid dynamics of the drying air in steady state. In a second step, it was added and transiently coupled heat and mass transfer phenomena related to drying. The experimental results allowed us to evaluate the relevance of the model. Several models isotherms were fitted to experimental data, and the model that best represented the data was modified Oswin, with coefficient of determination equal to 0.989. The phenomenological modeling and simulation performed correctly reproduced the behavior obtained in the experimental study, resulting in profiles of velocity, pressure, humidity and temperature. With the experimental results and the simulations carried out, it is noted that an amount of dry solid is always accumulated in the drying chamber until the feed is closed. The final product presented average humidity in the range of 5.37 to 7.3 % on a dry basis, which is in the commercially permissible range. Under the conditions tested, the feed of 0.80 mL min-1 generated better performances in the dryer, with efficiency of the recovered solid mass (58.27 %)

Airborne non-contact and contact broadband ultrasounds for frequency attenuation profile estimation of cementitious materials

[EN] In this paper, the study of frequency-dependent ultrasonic attenuation in strongly heterogeneous cementitious materials is addressed. To accurately determine the attenuation over a wide frequency range, it is necessary to have suitable excitation techniques. We have analysed two kinds of ultrasound techniques: contact ultrasound and airborne non-contact ultrasound. The mathematical formulation for frequency-dependent attenuation has been established and it has been revealed that each technique may achieve similar results but requires specific different calibration processes. In particular, the airborne non-contact technique suffers high attenuation due to energy losses at the air-material interfaces. Thus, its bandwidth is limited to low frequencies but it does not require physical contact between transducer and specimen. In contrast, the classical contact technique can manage higher frequencies but the measurement depends on the pressure between the transducer and the specimen. Cement specimens have been tested with both techniques and frequency attenuation dependence has been estimated. Similar results were achieved at overlapping bandwidth and it has been demonstrated that the airborne non-contact ultrasound technique could be a viable alternative to the classical contact technique.The authors acknowledge the support from University College Cork (Ireland), Universidad Politecnica de Valencia and the Spanish Administration under grant BIA2014-55311-C2-2-P and Salvador Madariaga's Programme (PR2016-00344/PR2017-00658).Gosálbez Castillo, J.; Wright, W.; Jiang, W.; Carrión García, A.; Genovés, V.; Bosch Roig, I. (2018). Airborne non-contact and contact broadband ultrasounds for frequency attenuation profile estimation of cementitious materials. Ultrasonics. 88:148-156. https://doi.org/10.1016/j.ultras.2018.03.011S1481568

Issues to be considered when measuring ultrasonic wave attenuation in austenitic cladding material

The experimental data obtained in a previous study is reprocessed to estimate the impact of several modifications of the measurement approach on the intrinsic longitudinal wave attenuation as a function of the propagation direction in reactor pressure vessel strip cladding. The measurement of the attenuation in anisotropic structures is a difficult task and this paper provides more insight on how the measurement approach works. It should help the reader to plan and carry out similar experiments.JRC.F.4-Nuclear Reactor Integrity Assessment and Knowledge Managemen

A Synopsis of the ENIQ 2nd Pilot Study

The objective of the ENIQ 2nd pilot study was to show how to fully exploit the potential of technical justifications (TJ) in the qualification of inspection procedures and thereby reduce the number of test piece trials on full-scale components. As the subject of the study a ferritic BWR-type nozzle to shell weld was selected. A TJ was produced, partly relying on modelling, to predict whether a designated ultrasonic inspection would be successful in detecting the specified defects. In parallel, a test piece with deliberately introduced defects was fabricated and inspected with the inspection system specified in the TJ. Predictions and inspection results were compared. In addition, as a separate exercise, three different mathematical models were used to predict the responses of the defects in the test piece to provide information on model applicability and accuray of prediction. The ENIQ 2nd pilot study has been largely successful in showing that TJs have the potential to predict the outcome of specific inspections and to reduce or remove the need for large scale test pieces in qualifiation. The project has shown that models are available which give largely conservative predictions of defect response when used within their regimes of validity.JRC.F.4-Nuclear design safet

Ultrasonic Wave Attenuation Measurements in RPV Cladding

Reliable ultrasonic inspections require a good understanding of the beam¿s behaviour within the inspected material. Among the physical parameters characterising the interaction of the beam with its supporting medium, ultrasonic attenuation is important because it limits the volume of the system that should be inspected, and is an input parameter for mathematical models, which play an increasingly important role in non-destructive testing by allowing computer simulations. In this study the predominantly scattering-induced longitudinal wave attenuation in RPV cladding is measured as a function of the propagation direction. The experimental data is obtained by an enhanced measurement technique, which requires mapping of the ultrasonic field transmitted through plane-parallel test pieces of different thicknesses. The high accuracy of the measurement technique has been previously demonstrated, and its superiority over conventional approaches is shown here once again.JRC.DDG.F.5-Safety of present nuclear reactor

Ultrasonic Properties of Reactor Pressure Vessel Strip Cladding

The modelling of ultrasonic wave propagation and beam-defect interactions in reactor pressure vessel cladding is demanding due to its anisotropic structure. It requires good knowledge of the ultrasonic properties in terms of the elastic constants and the intrinsic ultrasonic wave attenuation in order to obtain reliable simulation results. This paper provides experimental input data for mathematical models to simulate ultrasonic inspections of reactor pressure vessels with strip cladding. The measurement of the absolute ultrasonic wave attenuation is a particularly difficult task, and there is a lack of reliable data in the literature. Both a conventional and a more advanced experimental technique are applied to measure the attenuation of longitudinal waves. Reasons for the disagreement between the results obtained by means of the two measurement techniques are discussed.JRC.F.5-Safety of present nuclear reactor

Longitudinal Wave Attenuation Measurements in Ductile Cast Iron

The predominantly scattering-induced attenuation coefficient of a beam of longitudinal plane waves travelling in three different directions through a ductile cast iron specimen is measured as a function of the frequency. The experimental data is obtained by mapping the incident and the transmitted ultrasonic field, and by evaluating the energy loss experienced by each plane wave component of the beam. The high accuracy of this so-called energy method has been previously demonstrated, and its superiority over conventional approaches is shown here once again. The experimentally evaluated attenuation coefficient of high accuracy is an important input parameter for mathematical models, which play an increasingly important role in non-destructive testing by allowing simulations of inspection results without the time and cost of constructing specimens and performing measurements.JRC.F.5-Safety of present nuclear reactor

Enhanced Experimental Approach to Measure the Absolute Ultrasonic Wave Attenuation

The absolute ultrasonic wave attenuation is an important input parameter for mathematical models, which play an increasingly important role in non-destructive testing. The measurement of the absolute ultrasonic wave attenuation however is a difficult task. When conventional measurement techniques are applied, corrections to the raw data are required to account for apparent losses. In this study, a modified experimental approach is proposed to determine the absolute ultrasonic attenuation without any further corrections of the raw data.JRC.DG.F.5-Safety of present nuclear reactor