INCEFA-PLUS delivers new experimental data and new guidelines for assessment of environmental fatigue damage to ensure safe operation of European nuclear power plants.
Austenitic stainless steels will be tested for the effects of mean strain, hold time and material roughness on fatigue endurance. Testing will be in nuclear Light Water Reactor environments. The three experimental parameters were selected in the framework of an in-kind project during which the current state of the art for this technical area was developed. The data obtained will be collected and standardised in an online fatigue database with the objective of organising a CEN workshop on this aspect.
The gaps in available fatigue data lead to uncertainty in current assessments. The gaps, will be targeted so that fatigue assessment procedures can address behaviour under conditions closer to normal plant operation than is currently possible. Increased safety can thus be assured.
INCEFA-PLUS also develops and disseminates a modified procedure for estimating environmental fatigue degradation. This will take better account of the effects of mean strain, hold time and surface finish. This will enable better management of nuclear components, making possible the long term operation (LTO) of NPPs under safer conditions.
INCEFA-PLUS is relevant to the NFRP1-2014 programme because:
• Present guidance originates from NRC. In Europe various national programmes aim to develop counter proposals allowing greater operational efficiency with at least comparable safety assurance. INCEFA-PLUS brings these programmes together through which a strong EU response to the NRC methodology will be obtained with improved safety assurance through increased lifetime assessment reliability.
• INCEFA-PLUS improves comparability of data from EU programmes because partner laboratories will do some tests on a common material under common conditions. Reduced assessment uncertainty will enable easier maintenance of safety.
LEI activities in the Project
INCEFA-PLUS delivers new experimental data and new guidelines for assessment of environmental fatigue damage to ensure safe operation of European nuclear power plants. For this purpose, austenitic stainless steels (main circulation circuit steel) will be tested for the effects of mean strain, hold time and material roughness on fatigue endurance. INCEFA-PLUS also develops and disseminates a modified procedure for estimating environmental fatigue degradation. Testing will be in nuclear Light Water Reactor environments. The data obtained will be collected and standardised in an online fatigue database.
Most advanced EU research centers engaged in research in the nuclear energy field participate in INCEFA-Plus project. The project consortium consists of 16 organizations. Based on the project tasks, four work packages have been formed. LEI staff participates in two work packages: the first Project Management and the second Test program. During the project, Institute researchers will carry out experimental studies of austenitic steel fatigue in the air environment at room and operating temperatures. Furthermore, microstructural analysis of the tested specimens will be conducted. In 2015, regulatory documents and references related to fatigue tests were studied; first version of the fatigue test matrix was coordinated with all participating organizations. Coordinators of WP 2 Test program will assess capabilities of all organizations to carry out experimental studies and will prepare a final matrix of fatigue tests.
In 2016, EU programme Horizon 2020 project INCEFA-Plus was continued. Main objective of the project – to conduct fatigue damage research under reactor operation environment conditions, thus ensuring safe operation of European nuclear power plants. LEI Laboratories of Material Research and Testing and Nuclear Installation Safety participate in it. Regulatory documents and references related to fatigue tests were studied in 2016; in accordance with regulatory documents and the fatigue test matrix as submitted by the coordinator of the 2nd working package (Test program), LEI foreseen fatigue test programme was prepared and coordinated. In September 4 samples of 304L steel were received for fatigue research. Fatigue experimental research will be conducted in 2017 at the laboratory of Materials research and testing. At the present moment 304 steel samples are being manufactured for the alignment the experimental equipment.
Total cost: 6 140 668,75 EUR (LEI part: 41 263 EUR)
Coordinator: WOOD NUCLEAR LIMITED, United Kingdom
- PREUSSENELEKTRA GMBH, Germany
- PAUL SCHERRER INSTITUT, Switzerland
- UJV REZ, a.s., Czech Republic
- STUDIECENTRUM VOOR KERNENERGIE, Belgium
- TEKNOLOGIAN TUTKIMUSKESKUS VTT Oy, Finland
- LIETUVOS ENERGETIKOS INSTITUTAS, Lithuania
- CENTRO DE INVESTIGACIONES ENERGETICAS, MEDIOAMBIENTALES Y TECNOLOGICAS-CIEMAT, Spain
- INSTITUT DE RADIOPROTECTION ET DE SURETE NUCLEAIRE, France
- UNIVERSIDAD DE CANTABRIA, Spain
- COMMISSARIAT A L ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, France
- JRC -JOINT RESEARCH CENTRE- EUROPEAN COMMISSION, Belgium
- AREVA NP SAS, France
- ELECTRICITE DE FRANCE S.A., France
- INESCO INGENIEROS SL, Spain
- ROLLS-ROYCE POWER ENGINEERING PLC, United Kingdom