NUclear COmponents Based on Additive Manufacturing

Project Information

NUCOBAM

Grant agreement ID: 945313

DOI

10.3030/945313

Project closed

EC signature date 20 May 2020

Start date 1 October 2020

End date 30 September 2024

Funded under

• Euratom

Total cost

€ 4 067 916,75

EU contribution

€ 2 999 324,85

Coordinated by

COMMISSARIAT A L ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
France

Periodic Reporting for period 3 - NUCOBAM (NUclear COmponents Based on Additive Manufacturing)

Reporting period: 2023-10-01 to 2024-09-30

Summary of the context and overall objectives of the project

Most of the European nuclear power plants in operation were designed and built in the 1970s and 1980s, their components were generally manufactured by conventional metallurgical process. While these process practices have improved over the years in the delivery of high quality products, several reliability issues have emerged. In addition, improvements to the additive manufacturing process over the past 10 years have now made it possible to seriously consider these production processes in the nuclear context.
The objective of “NUclear COmponent Based on Additive Manufacturing” is to develop and qualify this new manufacturing for competitive implementation, efficient, optimized and more robust design of components to enable safe and continuous operation of the NPP and to consider life extension. The cost and availability of electricity are important issues for our society in the years ahead.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The project focuses on two components: the debris filter because its very complicated shape is usually difficult to manufacture using the usual casting and machining, and the valve because subjected to a typical charge of the nuclear power plant where temperature and high pressure level induce corrosion and aging of materials. The project will evaluate new quality control methods to ensure stability, repeatability and reproducibility of processes, resulting in high quality components.

The nuclear qualification of safety-related equipment requires significant investments that are possible in a 4-years project with 13 European partners. The ambitious irradiation program has started on 8 capsules (containing samples) which will be irradiated with neutrons (reactor in Belgium) at different doses with a long-term program (for 18 months). The project is ambitious in terms of the properties of the materials studied (nearly 12) and the post-treatment explored (4 heat treatments), including the variability of the process (4 manufacturers). More than 780 specimens have been manufactured and post-treated and will be tested as part of the project. Changes in material properties will be studied after representative ageing. The specimens will be exposed to heat for 10,000 hours (13 months at a higher temperature than in reality), which is equivalent to a very long plant life.
The development of such a manufacturing process could improve the reliability of the material, reduce the sequence of manufacturing steps, develop new, more efficient tools, improve material performance and develop a new component design.

The main deliverable – “Nucobam Methodology of AM qualification” reflects all the work performed during the 48 months of the project. All other Work Packages contributed to the demonstration that the new L-PBF 316L material meets all the nuclear properties requirements (better or equal to those existing in codification for a conventional 316L), and that both demonstrators “debris filter” and “body valve” passed in service requirements respectively -irradiation and geometrical conformability- and -thermomechanical loadings ageing and corrosion-, provided that the manufacturing of the new L-PBF 316L follows the procedure of qualification that has been established here in the Methodology and used for the production of all specimens and components of the project.

The “ultimate Deliverables are the two standard texts”, from the main Deliverable “Nucobam Methodology of AM qualification” :
• a proposal intended for RCC-M code (AFCEN) and
• a proposal intended for ASME-III code.

It should be noted here that submitting these proposals to the corresponding nuclear code’s committees is not included in the NUCOABM work plan. However, this work was initiated for the RCC-M by members of AFCEN,who were also experts in the "codification" task of this project and other French project.

The public deliverables will be found in the platform: https://nucobam.eu immedialtly after the final validation of the EC. The free access deliverables of the project are:
- Two Standard texts on Methodology of AM qualification
- A Scientific article on irradiation effet on mechanical properties
- The communication plan
- End User Group lessons learnt

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The strategy for acceptance of metal additive manufacturing in the nuclear sector is to implement directly the qualification of the process and component in nuclear design codes and standards, such as the French nuclear code for Design and Construction Rules for Mechanical Components or American standard. An End User Group was constituted from 15 others industries from 5 others country and with expertises combination on material, mechanical assessment, nuclear industry, and codification to promote our work in the nuclear field.
Obsolescence management remains a technical challenge for European asset owners, because Original Equipment Manufacturers, who were historically subjected to nuclear quality assurance requirements may not be willing to maintain their costly nuclear qualification. Most of those manufacturers have disappeared or have left the nuclear sector.
The project will help to develop in-depth qualifications new manufacturers or components and equipment. Metal additive manufacturing has the unique potential to produce near-to-shape components in a one-step manufacturing process, followed by post-processing steps. This unique approach will simplify the fabrication value chain and make it more reactive and effective for the delivery of unique part.
The project will contribute to create new Additive Manufacturing industry and support employment in Europe.

Regarding the preparing the exploitation of NUCOBAM results, 2 important actions were engaged and they will continue after Nucobam project:
- However submitting texts to committees is not included in the NUCOABM work plan, this work was initiated for RCC-M code by members of AFCEN, who are also experts in "codification".
- The End User Group members were interested in both the qualification methodology and the amount of experimental data produced on this material and some of us were able to promote directly the results of NUCOBAM project since some discussion are now undergoing with UNM Union de Normalisation de la Mécanique (the French sectorial standardization office for mechanical engineering, operating on behalf of AFNOR) in order to include experimental NUCOBAM data in a dedicated European standard on additive manufacturing of 316L by L-PBF.

NUCOBAM is focusing on two Additive Manufacturing Components: the Debris filter and the Valve