Environmental fatigue analysis of nuclear structural components: Assessment procedures, loads, and a case study

ABSTRACT: Nowadays, environmental fatigue assessment is mandatory in many countries, in the design and operational stages of nuclear structural components. The analysis of environmental fatigue can be a complex engineering process that is generally performed following national or international procedures. Such procedures are not always based on the same assumptions, and novel analysts may find a confusing variety of documents. Moreover, once a specific procedure has been chosen for the analysis, it is possible to complete the fatigue assessment by using design transients (and loads) or, alternatively, real loads provided by monitoring systems. In this context, this paper provides a comprehensive review of the different environmental fatigue assessment procedures and a brief description of the different types of load inputs (design vs. real data). The work is completed with a case study, in which the (fatigue) cumulative usage factor is estimated in a particular nuclear component by using one of the abovementioned assessment procedures (NUREG/CR-6909) and two options for the load inputsFunding: This research was funded by EURATOM, grant number 662320

Environmental Fatigue Analysis of nuclear components within the framework of INCEFA-SCALE project

ABSTRACT: INCEFA-SCALE started in October 2020. The objective of this project is to improve the capacity to predict the lifetime of Nuclear Power Plant (NPP) components subjected to environmental assisted fatigue. The project starts off by analysing the existing data and then provides new environmentally assisted fatigue data which allow the laboratory test outcomes to be applied to components with real geometries and loads. So far, the data mining of different finished projects (INCEFA-PLUS, USNRC, EPRI, MHI and AdFaM) has been carried out, and test conditions for filling the knowledge gaps have been established. Moreover, the test matrix for 2022 has been defined. In this first phase, tests are focused on producing reference data, analysing complex waveforms (variable amplitude) and the effect of the surface finish. The next testing phases will focus on particular conditions: multi-axial tests, notches, stress/strain gradient effect and size effect. Furthermore, the microstructural analysis of common materials and a guideline for fatigue striation measurement on the fracture surface have been developed. This article provides an update on the project status and the advances made in data analysis, mechanical understanding and testing conditionsThis project has received funding from the Euratom research and training program 2019-2020 under grant agreement No 945300. The contributions of all partners in the INCEFA-SCALE project are also acknowledge

INCEFA-SCALE (INcreasing Safety in NPPs by Covering Gaps in Enviro Assessment-Focusing on Gaps between Laboratory Data and Component-SCALE)

RESUMEN: INCENFA-SCALE es un proyecto de cinco años financiado por el programa Horizonte 2020 de la Comisión Europea,sucesor del proyecto INCEFA-PLUS. El objetivo de este proyecto es mejorar la capacidad para pronosticar la vida útil de los componentes de centrales nucleares sometidos a fatiga asistida por el ambiente. EPRI está llevando a cabo una serie de ensayos de fatiga ambiental a escala de componente, que se espera que avancen significativamente en la disponibilidad de datos. Sin embargo, la capacidad de abordar la aplicabilidad de los datos de ensayos en laboratorio a componentes con geometría y cargas reales sigue estando restringida por el limitado número de datos. Este déficit de conocimiento es abordado por INCEFA-SCALE mediante: 1) la comprensión mecánica mediante un examen detallado de probetas ensayadas a fatiga y análisis de datos (INCEFA-PLUS, USNRC, EPRI, MHI y AdFaM); 2) ensayos centrados en aspectos particulares de las cargas cíclicas aplicadas a componentes. En paralelo, se llevará a cabo una campaña de ensayos para cubrir las necesidades detectadas. Finalmente, el proyecto proporcionará una guía para aplicar en componentes a escala real los datos obtenidos en laboratorio. Este artículo describe los antecedentes del proyecto y los avances realizados en el análisis de datos, comportamiento mecánico y necesidades de ensayo.ABSTRACT: INCENFA-SCALE is a five-year project funded by the EC Horizon2020 programme, successor of the INCEFA-PLUS project. INCEFA-SCALE started in October 2020. The objective of this project is to improve the ability of predicting the lifetime of NPPs components subjected to environmental assisted fatigue. EPRI is developing a series of component-scale environmental fatigue tests, which are expected to significantly advance data availability. However, the ability to address the applicability of laboratory test data to components with real geometry and loads remains restricted by the limited number of data. INCEFA-SCALE addressed this knowledge gap by: 1) developing a comprehensive mechanical understanding through detailed examination of fatigue-tested specimens and data analysis (INCEFA-PLUS, USNRC, EPRI, MHI and AdFaM); 2) conducting tests focused on particular aspects of cyclical loads applied to components. At the same time, a test campaign will be carried out to cover the detected needs. Finally, the project will provide a guidance for using the laboratory data in full-scale components. This article describes the background of the project and the advances made in data analysis, mechanical understanding and testing needs.Este proyecto ha recibido financiación del programa de investigación y formación de Euratom 2019-2020, bajo el acuerdo de subvención nº 945300. También se reconoce la significativa contribución de los miembros del proyecto INCEFA-SCALE

Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora

International audienceThe Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% for the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/$c$ charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1$\pm0.6$% and 84.1$\pm0.6$%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation

Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora

International audienceThe Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% for the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/$c$ charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1$\pm0.6$% and 84.1$\pm0.6$%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation

Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora

International audienceThe Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% for the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/$c$ charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1$\pm0.6$% and 84.1$\pm0.6$%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation

Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora

International audienceThe Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% for the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/$c$ charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1$\pm0.6$% and 84.1$\pm0.6$%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation