During the first part of the project, technical and environmental dismantling requirements of the European operators were shared. This provided a good overview of the graphite reactor decommissioning situation as well as an understanding of similarities and differences. It also allowed to identify discrepancies to be considered in R&I during and after the INNO4GRAPH lifetime and to build a common development roadmap for future developments.
Besides, developments, evaluation of tools and methodologies in laboratory or representative environments were carried out during the second part of the project: 3D modelling and physical demonstrations using the graphite mock up designed and built during the first part of the project. Knowledge of graphite properties were further improved by novel techniques of graphite properties prediction.
From the technical specifications defined on in-situ crack detections, a prototype was set up and tested. From the established state of the art and with data collected from NPP operators, several Non-Destructive Tools to measure corrosion were identified on reactor cases.
The representative mock-up of the graphite stack was designed, manufactured and installed at the EDF Industrial Demonstrator. It was used to perform tests on the operational graphite retrieval tools and the way to remotely operate them.
From the test methodology defined to assess the risk of bulk-oxidation of the graphite during cutting operations, data about the oxidation behaviour of different graphite samples was collected.
Innovative tools were developed with the aim to make them available during the dismantling operations.
In particular, a proper coating painting was investigated in order to reduce the contamination risk during graphite extraction and handling and coated samples tested in order to assess structural, thermal and mechanical properties.
Laser cutting tests were carried out on graphite samples to study the applicability and assess the technical feasibility of laser cutting technology on graphite blocks.
Studies regarding the specific needs for the multi-joint manipulator in graphite reactors were performed to select, model in a virtual environment and test characteristics for a future development.
A deployment system was designed during the project for graphite retrieval tools. Its aim is to deploy and operate the different tools necessary to dismantle the graphite stack from a mobile dismantling platform set up above the reactor. The system designed will then be manufactured and later tested in the Industrial Demonstrator beyond the Project.
Using DEMplus® software, 3D simulations were used during the tool developments to better understand the physical environment and constraints. 3D simulations of graphite bricks retrieval were also performed allowing to evaluate feasibility of operations, in terms of accessibility, cost, duration, collective dose and wastes generated.
By developing tools that provide more in-depth information about the graphite mechanical properties and tools that decrease the risk of handling radioactive material, the safety and cost-efficiency of the dismantling operations can be increased.
Moreover, the development of new techniques and the expertise gained within the project has already generated knowledge. A training programme was defined based on areas of learning and lessons learned for graphite reactor decommissioning. An innovative module using interactive viewer was developed as an example of training module.
All along the project, the consortium has been active in conferences, disseminating the project results to the stakeholders of the graphite decommissioning field. 4 publications were published:
https://shorturl.at/kmBS6(odnośnik otworzy się w nowym oknie). Synergies could also be initiated thanks to the EU support and its EURATOM Programme with projects such as LD safe (
https://ldsafe.eu/(odnośnik otworzy się w nowym oknie)) or CLEANDEM (
https://shorturl.at/mrwAQ(odnośnik otworzy się w nowym oknie)).
On Oct. 2023, the project ended with an international event (
https://shorturl.at/ILPZ2(odnośnik otworzy się w nowym oknie)) showcasing the following outcomes:
- The graphite reactor data gathering and comparison
- The design of tools and deployment systems for investigations and dismantling
- The testing of innovative solutions, such as laser cutting
- The 3D simulations of scenarios of thousands of graphite brick removal.
