Fractures of Irradiated Austenitic and Ferritic Materials
Prediction of Fracture Properties of Irradiated Austenitic and Ferritic Materials for Reactor Components of Nuclear Power Plants on the Basis of Multi-Scale Approach
Tech Area / Field
- FIR-MAT/Materials/Fission Reactors
- FIR-NSS/Nuclear Safety and Safeguarding/Fission Reactors
8 Project completed
Senior Project Manager
Kirichenko V V
TsNIIKM PROMETEY (Construction Materials), Russia, St Petersburg
- Serco Assurance, UK, Warrington\nCEA / DEN / Department des Matériaux pour le Nucléaire / Service Recherches Métallurgiques Appliquées, France, Gif-sur-Yvette Cedex\nAREVA / Areva NP GmbH, Germany, Erlangen\nSCK-CEN, Belgium, Mol
Project summaryIntroduction and Overview. At the present time, researches in the area of plant life assessment and management are extremely important for NPP with RPVs of WWER type in both Russia and Ukraine and the EU countries. It is connected with lifetime extension for basic NPP equipments up to lifetime of 60 years and when guaranteeing safe operation. The major task of mechanics and physics of reactor vessel and internals materials, in a framework of nuclear plant safety problem, is the prediction of the irradiation damage effects on basic fracture properties of these materials that are used for assessment of structural integrity of RPV and serviceability of internals.
The most promising approach for long-term prediction of basic properties of irradiated reactor and internal materials is multi-scale modelling of irradiation damage, micro-damage accumulation and fracture on meso- and macro-scales. At the present time this approach is intensively developed. In particular, under the EURATOM 6th FP, the integrated project PERFECT and the EC-sponsored ISTC project 3072 which collaborated with PERFECT have been devoted to multi-scale modelling of irradiation damage in steels used in nuclear application. For the EURATOM 7th FP, new project PERFORM 60 dealing with multi-scale modelling of damage in nuclear materials is proposed.
Taking into account successful collaboration between the EU PERFECT project and ISTC project 3072 and discussion with the ISTC project 3072 collaborators, D. Lidbury and E. Keim and other participants of EURATOM FP 7 Projects, the present new ISTC proposal has been prepared. This proposal was supported by EU Contact Expert Group on Plant Life Management on the 7th meeting held at VTT in February 2008.
The purpose of the proposed ISTC project is to provide models and procedures for long-term prediction of basic properties of irradiated reactor and internal materials by means of multi-scale modelling of irradiation damage, micro-damage accumulation and fracture on meso- and macro-scales. This multi-scale approach is fully compatible with the most advanced techniques which are being developed in the world, in particular those related to the micro-, meso- and macromechanistic analysis for the prediction of irradiation damage effects in reactor components in the framework of the PERFORM 60 project, which is being performed by the foreign collaborators.
This new ISTC project will be performed by CRISM Prometey participants of the ISTC project 3072 in cooperation with new EU Project PERFORM 60 and will interact with the European Network of Excellence NULIFE.
The ISTC project will contribute to the main objectives of the PERFORM 60 project:
- to develop the Advanced Fracture Toughness Module (AFTM), which will provide the deformation and fracture properties of the irradiated RPV steel;
- to provide deeper understanding of the radiation embrittlement phenomena and to propose numerical tools for prediction of basic properties of irradiated nuclear materials and for assessment of NPP components life;
- to enrich European Collective Exercise of NPP component analysis in which material behaviour assessment will be done by numerical simulation with the proposed tools.
- to use the proposed simulation tools to complement previous or current international research programs (EURATOM 6th PERFECT, FUSION, TACIS, PHARE and others).
The proposed ISTC project will be executed by the specialists of CRISM “Prometey” in collaboration with European specialists actively involved in the development of leading-edge technologies as the PERFORM 60 project is world-wide recognized. This close collaboration with the most relevant European specialists who are familiar with such techniques will contribute to enhance Prometey’s positioning into the global scientific community by guaranteeing that the results of the project can be easily integrated into international exercises of prediction of irradiation effects on NPP reactor materials.
Expected Results and Their Application. In the framework of the project the following tasks will be solved.
Task 1. Construction of the design fracture toughness curve on the basis of tests of sub-size specimens (surveillance specimens). Task 2. Determination of the temperature dependence of the minimum possible value of fracture toughness Kmin = f(T) for RPV steels. Task 3. Prediction of fracture toughness of austenitic steels undergone to neutron irradiation. Task 4. Modelling of fracture under creep and irradiation for austenitic steels.
The developed methods and expected results are intended to be contributed to EURATOM 7th FP PERFORM 60 project. The study results will be represented on workshops of the PERFORM 60 project and international conferences and articles in international scientific journals.
The scientific significance of the project consists in development of models of brittle fracture, ductile stable and unstable fracture and fracture under creep allowing for irradiation damage, and in elaboration of methods and approaches for analysis of crack behaviour in solids.
The practical significance of the project is to provide advanced methods and procedures for assessment of structural integrity and service lifetime for the irradiated RPV and internals for NPP. On the basis of the obtained results, more adequate predictions of fracture toughness for irradiated RPV and internals materials and the corrected assessment of service life for NPP components may be obtained. In future, approaches elaborated in a frame of the project will be incorporated in Standards for assessment of structural integrity of the irradiated NPP components. One of the derived outcomes of the project will be to place Prometey in a better position to valorize and commercialize its knowledge and technology capacities before utilities, nuclear safety regulators, nuclear engineering companies and manufacturers of capital goods for the nuclear industry all around the world.
Meeting ISTC Goals and Objectives. The Project completely meets ISTC aims. It provides scientists and personnel formerly engaged in weapons development an opportunity to conduct research aimed at peaceful activity because the RPV elements involved are only applied to NPPs. It promotes real integration of Russian scientists into the international scientific community and reinforces their adaptation to market economy for future subcontracting of services in the field of nuclear technology; it supports basic and applied research for peaceful purposes, especially in fields of energy production and nuclear safety. Besides, the Project solves international technical problems, via interaction with EURATOM 7th FP Project PERFORM 60.
Scope of Activities. The proposed project is a complex of theoretical, calculated and experimental investigations aimed for development of the brittle and ductile fracture models and model of fracture under creep with regard for irradiation damage, and for elaboration of methods for analysis of crack behaviour in solids in order to predict the irradiation damage effect on basic fracture properties of NPP irradiated materials. Main outputs of the expected results are the assessment methods of structural integrity of NPP components on criteria of crack initiation, growth and unstable propagation that are based on advanced physical, mechanical and engineering approaches. In the framework of the project four tasks will be solved. Publications, presentations on conferences and technical reports will be provided as deliverables. The project results will contribute to the EURATOM 7th FP Project PERFORM 60.
Role of Foreign Collaborators/Partners. During performing the project the researchers from CRISM “Prometey” will continue close collaboration with the participants of the project from United Kingdom, Germany, France and other European specialists. The followings issues will be discussed: theoretical models and calculation methods; program and work schedule of common researches; main results of investigation; preparation of common publications and presentation on conferences. As a result of common activity of Russian and European scientists a decisive contribution will be made to solving the problem being of interest from the point of view applications to the safety of nuclear power plants.
Technical Approach and Methodology. Approaches and methods of solid mechanics, fracture mechanics (local and global approaches), physics of strength, plasticity and fracture will be used. Each task includes theoretical, calculative and experimental studies. Calculative investigations will be performed by analytical and numerical methods, mainly, by finite element method (FEM) by using standard (ANSYS, MARC) and special PC programmes. Experimental studies will be carried out according to native and international standards and normative documents as well as by using original procedures. Theoretical studies will be based on the Prometey probabilistic model of brittle fracture and the Unified Curve concept developed in the frame of the ISTC project 3072, and will be performed by micro- and meso-scale modelling of the effect of irradiation on mechanisms of trans-and intercrystalline fracture.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.