Periodic Reporting for period 2 - ENTENTE (European Database for Multiscale Modelling of Radiation Damage)
Periodo di rendicontazione: 2022-03-01 al 2023-08-31
ENTENTE aims to design a new European experimental/modelling materials database to collect and store highly-relevant data on radiation damage of Reactor Pressure Vessel (RPV) steels, according to FAIR (Findability, Accessibility, Interoperability, and Reusability) principles.
The specific objectives can be grouped into technical and exploitation objectives. Specific technical objectives of the project are:
-Design and maintain a unique experimental/modelling database for model validation and calibration
-Collect previous data and enrich the database with microstructural and mechanical data on neutron irradiated RPV materials to fill gaps
-Development of advanced models based on data analytics/mining and previous knowledge
The exploitation objectives of the project are:
-IMPROVE THE SOTERIA PLATFORM
-ENCOURAGE DISSEMINATION OF RESULTS
-FOSTER INTERNATIONAL COOPERATION
Characterization of un-irradiated materials microstructures has been carried out to have the reference data for experiments with irradiated material but also as input for modelling actions. Modelling effort is applied focusing on various, embrittlement related topics. Hybrid-(O)KMC models has been demonstrated and constructed to incorporate microstructural effects, chemical component heterogeneities and irradiation effects. Combination of APT/PAS technique with DFT modelling approach was brought to operational condition and the verification of the models are being performed. Initial comparison shows very encouraging results and suggests that the models are capable of addressing effects of local segregation quite well.
The ENTENTE exploitation team has been set-up with relevant EU and non-EU industrial partners to assess the fitness of the ENTENTE database and SOTERIA platform to study different reference cases. Some reference cases were identified to support ASME code cases on the use of Master Curve. The interaction within different projects and initiatives has been done in several meeting, instead for a single meeting, as most of them were done through video conferences. The most representatives are the dialogue with SNTEP sister project STRUMAT-LTO and FRACTESUS as this project also deals with the RPV embrittlement assessment. Also a strong communication has been established with different NEA expert groups
Working with the Phimeca team, CLOCK is now running within the SOTERIA environment with all tests passing. The output format has been finalised, including the input of image resolution, conversion of a real density to volumetric density, and error bars on the result. A typical TEM image can now be analysed automatically in about 5 min on a single processor
An innovative atomistic model is developed, combining quantum mechanics/molecular mechanics of the crack propagation in the presence of irradiation defects and realistic segregation level at grain boundaries. The developed combination of integrated computational materials engineering, machine learning boosted simulation/data processing methods, and hybrid-atomistic scale simulation approaches can be widely applied to various industrial sectors and sustained materials design. Hardening models based on the Nix-Gao approach and their application to predict the bulk-equivalent hardness of ion-irradiated layers of RPV steels from measured dependencies of the nanoindentation hardness on the contact depth have been elaborated.
FRA-G developed and applied two industrial relevant reference cases for the prediction of neutron embrittlement of RPV materials for LWRs for which comprehensive information is available ranging from the microstructure to the surveillance results (e.g. Charpy data, fracture toughness). These two references are related to mechanical properties and of high importance and benefit for end users, and contribute to the validation of following ASME code cases:
- ASME Code Case N-830 Revision 1: “Case N-830-1 Direct Use of Fracture Toughness for Flaw Evaluations of Pressure Boundary Materials in Class 1 Ferritic Steel Components Section XI, Division 1”.
- ASME Code Case N-914: “Accounting for the Effect of Embrittlement on Fracture Toughness Properties Used in Evaluations of Pressure Boundary Materials in Class 1 Ferritic Steel Components”.