An extended BEPU approach integrating probabilistic assumptions on the availability of safety systems in deterministic safety analyses

[EN] The International Atomic Energy Agency (IAEA) produced guidance on the use of Deterministic Safety Analysis (DSA) for the design and licensing of Nuclear Power Plants (NPPs) in "DSA for NPP Specific Safety Guide, No. SSG-2", which proposes four options for the application of DSA. Option 3 involves the use of Best Estimate codes and data together with an evaluation of the uncertainties, the so called BEPU methodology. Several BEPU approaches have been developed in scopes that are accepted by the regulator authorities nowadays. They normally adopt conservative assumptions on the availability of safety systems. Option 4 goes beyond by pursuing the incorporation of realistic assumption on the availability of safety systems into the DSA. This paper proposes an Extended BEPU (EBEPU) approach that integrates insights from probabilistic Safety Analysis into a typical BEPU approach. There is an aim at combining the use of well-established BEPU methods and realistic ("probabilistic") assumptions on safety system availability. This paper presents the fundamentals of the EBEPU approach and the main results obtained for an example of application that focuses on an accident scenario corresponding to the initiating event "Loss of Feed Water (LOFW)" for a typical three-loops Pressurized Water Reactor (PWR) NPP.This work has been developed partially with the support of Programa de Apoyo a la Investigacion y Desarrollo of the Universitat Politecnica de Valencia (PAID UPV).Martorell Alsina, SS.; Sanchez Saez, F.; Villanueva López, JF.; Carlos Alberola, S. (2017). An extended BEPU approach integrating probabilistic assumptions on the availability of safety systems in deterministic safety analyses. Reliability Engineering & System Safety. 167:474-483. doi:10.1016/j.ress.2017.06.020S47448316

E-learning in "innovation, creativity and entrepreneurship": Exploring the new opportunities and challenges of technologies

[EN] Companies and society demand professionals be able to provide creative solutions with added value as well as to implement them in order to face the arising challenges in the increasingly dynamic environment. Although the transversal competence ¿Innovation, Creativity and Entrepreneurship¿ is essential for engineers that should find innovative solutions to problems, teachers find many difficulties when training and evaluating their students in the scope of the regular courses: large groups, very adjusted time to technical contents. In this context, the School of Industrial Engineering (ETSII) at Polytechnic University of Valencia (UPV) is aware of the opportunities offered by new information and communication technologies to support teachers in this task while enhancing students¿ generic outcomes. For this reason, an e-learning platform has been created on this competence, that offers valuable resources to students to implement this competence throughout the assigned course tasks, and supports teachers prompted to train and evaluate this transversal competence. With this platform, the authors aim to contribute to the still neglected educational aspect of entrepreneurship and address for the first time in an e-learning system its relationship with innovation and creativity.The authors acknowledge the financial support partly from the ETSII of UPV and partly from the Universitat Politècnica de València through the Coordinación metodológica a través de webs de apoyo en las titulaciones de la ETSII para las Competencias Transversales PIME/19-20 Ref.150, Ref.151 and Ref.152 projects.Alemany Díaz, MDM.; Vallés Lluch, A.; Villanueva López, JF.; García-Serra García, J. (2021). E-learning in "innovation, creativity and entrepreneurship": Exploring the new opportunities and challenges of technologies. Journal of Small Business Strategy (Online). 31(1):39-50. http://hdl.handle.net/10251/189826395031

Diseño de rúbricas para la evaluación de competencias transversales. Aplicación a Trabajos Fin de Grado en ingeniería

[EN] In the Context of the European Higher Education Area (EHEA) it is necessary to guarantee that at the end of the degree the different competences have been achived, the specific skills of the subjects studied of each degree and the acquisition of another skills, so-called transversal competences. In this context, the institutional project of Transversal Competence of the Universitat Politècnica de València (TC-UPV) carries out a classification in 13 competences, worked through three different ways (degree subjects, Bachelor´s Thesis (BT)/Master´s Thesis (MT) and extracurricular activities) and in different mastery levels. BT and MT do not have a methodology that systematizes the identification, analysis and the assessment of the competences, among other reasons, for the wide spectrum of subjects studied. In this latter case, the tutor shall be responsible for performing this work. In order to detect the main problems that students face in the development of their Bachelor’s Thesis has been performed the present work. After the tutoring experience gained and through the analysis of different surveys outcomes, it was concluded that effort should be reinforced in the following transversal competences: time management, effective communication, analysis and practical thinking. So, the department has designed specific rubrics of these competences.[ES] En el contexto del Espacio Europeo de Educación Superior es necesario garantizar que a la finalización del grado se han adquirido diferentes competencias, tanto específicas como transversales. El proyecto institucional Competencias Transversales de la Universitat Politècnica de València realiza una clasificación de estas, que se trabajan mediante tres vías diferentes (entre ellas los Trabajos Fin de Grado) y en diferentes niveles de dominio. Sin embargo, en TFG no se dispone de una metodología que sistematice la identificación, análisis y evaluación de las competencias, entre otras razones, por el amplio espectro de temas que se estudian, siendo en este caso el tutor el responsable de realizar esta labor. En este trabajo, se ha elaborado un cuestionario para detectar cuáles fueron los principales problemas durante el desarrollo del TFG por parte de un grupo de alumnos. Tras la experiencia adquirida en la tutorización y mediante el análisis de los resultados del cuestionario, se concluyó que se debía reforzar el trabajo en las siguientes competencias: gestión del tiempo, comunicación efectiva, análisis y pensamiento práctico. Con el objetivo de sistematizar el proceso de evaluación, se han diseñado unas rúbricas específicas para estas competencias.Este trabajo se ha realizado en el marco del proyecto Proyecto de Innovación y Mejora Educativa, PIME Curso 2017-2018 “Coordinación de competencias transversales en asignaturas de ámbito nuclear en el Grado de Ingeniero de la Energía”, Referencia B07, del Vicerrectorado de Estudios, Calidad y Acreditación de la Universitat Politècnica de València.Martón Lluch, I.; Gallardo Bermell, S.; Villanueva López, JF.; Ordóñez Ródenas, J. (2018). Diseño de rúbricas para la evaluación de competencias transversales. Aplicación a Trabajos Fin de Grado en ingeniería. En IN-RED 2018. IV Congreso Nacional de Innovación Educativa y Docencia en Red. Editorial Universitat Politècnica de València. 1542-1554. https://doi.org/10.4995/INRED2018.2018.8789OCS1542155

RELAP5 Simulation of PKL Facility Experiments under Midloop Conditions

[EN] Nuclear power plant risk has to be quantified in full power and in other modes of operation. This latter situation corresponds to low power and shutdown modes of operation in which the residual heat removal (RHR) system is required to extract the heat generated in the core. These accidental sequences are great contributors to the total plant risk. Thus, it is important to analyze the plant behavior to establish the accident mitigation measures required. In this way, PKL facility experimental series were undertaken to analyze the plant behavior in other modes of operation when the RHR is lost. In these experiments, the plant configurations were changed to analyze the influence of steam generators secondary side configurations, the temperature inside the pressurizer, and the inventory level on the plant behavior. Moreover, different accident management measures were proposed in each experiment to reach the conditions to restart the RHR. To understand the physical phenomena that takes place inside the reactor, the experiments are simulated with thermal-hydraulic codes, and this makes it possible to analyze the code capabilities to predict the plant behavior. This work presents the simulation results of four experiments included in PKL experimental series obtained using RELAP5/Mod3.3.This study is part of the work developed by the Polytechnic University of Valencia within a project of the OECD, in which authors are participating under the leadership of the Consejo de Seguridad Nuclear (STN/4524/2015/640). The authors thank PKL III, especially AREVA, program organizers for the information supplied.Villanueva López, JF.; Carlos Alberola, S.; Sánchez Sáez, F.; Martón Lluch, I.; Martorell Alsina, SS. (2017). RELAP5 Simulation of PKL Facility Experiments under Midloop Conditions. Science and Technology of Nuclear Installations. 2017:1-11. https://doi.org/10.1155/2017/6140323S111201

Project Based Learning in the subject of Energy and sustainable development

[EN] The standards and guidelines for quality assurance in the European Higher Education Area (EHEA) lay down that one of the keys to combining learners¿ knowledge and skills is the implementation of new more student-centred methodologies, and learning based on competences. One of the most widely used and effective active learning methodologies is Project-Based Learning (PBL). This is a practical pedagogical methodology in which the student carries out a project focused on solving a real problem by applying the theoretical concepts from a practical point of view. In this work, projects implanted using the PBL methodology are aligned with the Agenda 2030. This Agenda for Sustainable Development, approved in 2015, establishes that the universities must play a major role in compliance with it, in due consideration of their responsibility in relation to training, research, relations with society and a model for higher education governance. This agenda contains 17 Sustainable Development Goals (SDGs). This proposal is focused on Goal 7, ¿Affordable and Clean Energy¿. In the framework of the PBL methodology and integrating the SDGs of the Agenda 2030, the main goal of this work is the development of project-based learning in the subject "Energy and Sustainable Development" in the bachelor¿s degree in Energy Engineering at the Universitat Politècnica de València. The paper described the developed methodology, the results achieved and the initial conclusions obtained.This work was carried out within the framework of the PIME's Educational Improvement and Innovation Project 2018-2019 Coordination of transversal competences in nuclear subjects of the Energy Engineering Degree, Referencia B16, del Vicerrectorado de Estudios, Calidad y Acreditación de la Universitat Politècnica de València.Marton Lluch, I.; Villanueva López, JF.; Gallardo Bermell, S.; Carlos Alberola, S.; Sánchez Galdón, AI. (2020). Project Based Learning in the subject of Energy and sustainable development. IATED Academy. 4811-4819. https://doi.org/10.21125/edulearn.2020.1266S4811481

Optimización informada en el riesgo de la vigilancia y mantenimiento aplicado al sistema de disparo del reactor

Los equipos pertenecientes a Centrales Nucleares deben cumplir objetivos de fiabilidad y seguridad de funcionamiento; más aún si se trata de equipos pertenecientes a sistemas de seguridad. Las actividades de vigilancia y el plan de mantenimiento que se les asigna tienen un papel decisivo en la consecución, e incluso maximización, de dichos objetivos. En este contexto, el objetivo de la ponencia se centra en presentar el desarrollo de un método, y su aplicación, que permite la optimización integral de la vigilancia y el mantenimiento en base a criterios RAM+C (Reliability, Availability, Maintainability, Cost). El método para obtener el plan de mantenimiento óptimo se plantea como dos problema de optimización mono-objetivo, donde los parámetros asociados al plan actúan como variables de decisión mientras que los parámetros RAM+C intervienen como criterios de decisión, bien como funciones objetivo o como funciones restricción al rango de posible soluciones alternativas. Por ser un problema suficientemente complejo, que no puede ser resuelto con un método analítico, las técnicas heurísticas surgen como una alternativa viable para su resolución. Entre estas, los algoritmos genéticos tienen características que los hacen ideales para este tipo de problemas. La principal es el paralelismo implícito; es decir, la capacidad de realizar la búsqueda en más de un punto a la vez. Por ello, se propone un Algoritmo Genético mono-objetivo como técnica de optimización. Finalmente, se presenta un caso de aplicación centrado en la optimización de pruebas y mantenimientos del Sistema de Disparo del Reactor.Martorell Alsina, SS.; Villamizar León, MP.; Villanueva López, JF. (2011). Optimización informada en el riesgo de la vigilancia y mantenimiento aplicado al sistema de disparo del reactor. Sociedad Nuclear Española. http://hdl.handle.net/10251/71499

Uncertainty analysis of a loss of cooling and loss of coolant accident in a spent fuel pool using TRACE

[EN] In this work the fundamentals and application results of an uncertainty analysis of a loss of coolant and loss of cooling accident in a spent fuel pool are presented. The spent fuel pool was modeled with TRACE V5.0 Patch 5 using a VESSEL 3D component in Cartesian coordinates. A more detailed nodalization was necessary as compared with a previous study of the same accident scenario to better develop the uncertainty analysis in the framework of the Best Estimate Plus Uncertainty (BEPU) approach. First, the model was calibrated using Main Yankee spent fuel pool experimental data of temperatures and flows measured in steady state conditions. Using the calibrated model, the analysis of the accident was performed considering uncertainty in boundary conditions and in all the coefficients included in the TRACE uncertainty quantification data module. The figure of merit selected in this work is the time at which the cladding oxidation reaches 0.17 times the cladding thickness before oxidation (CFR 50.46 b2). The uncertainty analysis was performed using Wilks' method and surrogate models. In particular, the Elastic Net surrogate model has demonstrated its potential not only to predict the evolution of the figure of merit in an appropriate way with lower computational effort than the Wilks' method but also its capability to identify the most relevant uncertain parameters, such as the fuel and cladding specific heats, rod internal pressure coefficient, burst temperature coefficient, a group of fluid regime heat transfer coefficients, the cladding metal-water reaction rate coefficient and the cladding tolerance for the average cores. In addition, the surrogate model provides more information of the distribution of the evolution of the figure of merit. The estimations of the 5/95 tolerance limits, both with the Wilks' method and with the surrogate models, are very similar, ranging from 30.432 to 30.461 h.The authors are grateful to the Spanish "Consejo de Seguridad Nuclear (CSN)" for the financial support they provided for Research MASA Project 2 and STN/4524/2015/640 (CAMP Project).Sanchez-Saez, F.; Carlos Alberola, S.; Villanueva López, JF.; Sánchez Galdón, AI.; Martorell Alsina, SS. (2020). Uncertainty analysis of a loss of cooling and loss of coolant accident in a spent fuel pool using TRACE. Progress in Nuclear Energy. 124:1-8. https://doi.org/10.1016/j.pnucene.2020.1033451812

Uncertainty analysis of PKL SBLOCA G7.1 test simulation using TRACE with Wilks and GAM surrogate methods

[EN] The Nuclear Energy Agency auspices simulation of experiments in different facilities under several programs. One on them consisted of performing a counterpart test between ROSA/LSTF and PKL facilities, with the main objective of determining the effectiveness of late accident management actions in a small break loss of coolant accident. The results obtained by TRACE code for PKL experiment SBLOCA G7.1 (a scaled model of Konvoi reactor) were in good agreement with the experiments. However, in the simulation process, uncertainty was not accounted. Uncertainty, analysis, following the principles of Best Estimate Plus Uncertainty (BEPU) approach, must be performed to measure the effect of uncertainties on the evolution of safety variables of interest, such as the maximum of the Peak Cladding Temperature (PCTmax) in the experiment. In this paper we present a comparison between two uncertainty analysis techniques. The first technique is based on order statistics that makes use of Wilks' formula. The second technique is based on a Generalized Additive Model (GAM) that substitutes the thermal-hydraulic code, without and with consideration of errors in adjusting the GAM model. The comparison of the uncertainty analysis results makes use of several performance metrics such as coverage, Coefficient of Variation and conservativeness. Based on the results of these metrics it can be concluded that the GAMPE (GAM Plus Error) provides the best performance, in particular, when using small sample size, i.e. n = 59, 93. For larger sample sizes, i.e. n = 124, 153, GAMPE and Wilks' results presents similar performance.This work has been developed partially with the support of Programa de Apoyo a la Investigacion y Desarrollo of UPV (PAID). Authors are grateful to Spanish CSN (Consejo de Seguridad Nuclear) for the financial support of these researches: (Research Project SIN/4078/2013/640; MASA Project) and (Research Project STN/4524/2015/640; CAMP Project).Sánchez Sáez, F.; Carlos Alberola, S.; Villanueva López, JF.; Sánchez Galdón, AI.; Martorell Alsina, SS. (2017). Uncertainty analysis of PKL SBLOCA G7.1 test simulation using TRACE with Wilks and GAM surrogate methods. Nuclear Engineering and Design. 319:61-72. https://doi.org/10.1016/j.nucengdes.2017.04.037S617231

Creación de pruebas de evaluación para valorar el progreso y acreditación de competencias en la asignatura Vibraciones Mecánicas

[ES] La puesta en marcha de los nuevos planes de estudio englobados en el Espacio Europeo de Educación Superior (EEES) implica un cambio en el enfoque de la enseñanza universitaria. Estos planes de estudio están basados en una formación en competencias, tanto genéricas (o transversales) como específicas de la titulación. En el actual trabajo se presenta una metodología para evaluar el grado de adquisición de las distintas competencias trabajadas en una asignatura. Se muestra la aplicación a la asignatura Vibraciones Mecánicas, correspondiente al plan de estudios de Grado en Ingeniería Mecánica (GIM).Rovira Cardete, A.; Clemente Císcar, M.; Lajara-Camilleri, N.; Villanueva López, JF. (2014). Creación de pruebas de evaluación para valorar el progreso y acreditación de competencias en la asignatura Vibraciones Mecánicas. En Strategies for education in a new context: INNODOCT'14 : International Conference on Innovation, Documentation and Teaching Technologies, held on-line in Valencia, Spain, on 8-9 May, 2014. https://riunet.upv.es/handle/10251/40350. Editorial Universitat Politècnica de València. 696-705. http://hdl.handle.net/10251/8218369670

Modelo de transmisión de calor por radiación en una piscina de combustible gastado mediante TRACE

El trabajo desarrollado consiste en la simulación termohidráulica de una piscina de combustible gastado al producirse un transitorio de pérdida de refrigerante con pérdida de refrigeración a través del canal de transferencia. La simulación se realiza con el código Best Estimate TRACE. Para seguir la evolución del comportamiento de la piscina, una variable importante a seguir es la temperatura de vaina, cuya evolución depende del calor que consiga emitir. En esta simulación se ha considerado la transmisión por convección y se ha comparado con la evolución de la variable si se considera convección más radiación. El modelo de radiación propuesto obtiene datos del código RADGEN para ser utilizados en TRACE. Con este modelo, se obtiene una evolución de la Temperatura de vaina en el transitorio menos conservadora.Sanchez Saez, F.; Carlos Alberola, S.; Martorell Alsina, SS.; Villanueva López, JF. (2013). Modelo de transmisión de calor por radiación en una piscina de combustible gastado mediante TRACE. Sociedad Nuclear Española. http://hdl.handle.net/10251/71619