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TRANSversal Actions for Tritium

Periodic Reporting for period 2 - TRANSAT (TRANSversal Actions for Tritium)

Reporting period: 2019-03-01 to 2020-08-31

Tritium is present in fission and fusion reactors and it is already the main radioisotope released in the environment. Strategies have to be elaborated to mitigate tritium sources, to improve the tritiated waste management as well as the knowledge on its radiotoxicity, radiobiology, dosimetry. These are the main goals of TRANSAT.
To limit the tritium sources, TRANSAT will focus on technologies reducing tritium permeation or on in situ operational effluents treatment. Modelling tools for tritium inventory and tritium permeation fluxes estimation in fusion and fission devices will be benchmarked to improve the level of confidence of their estimation.
Tritium is absorbed/migrates in any material. For tritiated waste, tritium release is related to its inventory/profile in the material. TRANSAT will focus on innovative measurements to assess both tritium inventory and profile. New concept of confining drums will be also studied to improve tritiated waste storage capabilities.
TRANSAT is also proposing to improve knowledge in the field of radiobiology, dosimetry, radiotoxicology, genotoxicology and ecotoxicology in case of contamination by tritiated dust (Steel and cement) that are produced during decommissioning of nuclear facilities.
"One TRANSAT activity is focused on the assessment of the fusion and fission tritium sources and the development of tritium permeation barriers. After the tritium source evaluation, the development of permeation barriers have been undertaken focused on components of heat exchangers. Different tritium experiment rigs are commissioned, the first tritium experiments have been carried out and the permeation barrier efficiency is under estimation. Following the assessment of the treatment of the operational tritiated gases generated in fission and fusion, experimental activities started. The work is focused on the investigation of the performance of a membrane reactor for tritiated water decontamination.
In TRANSAT, innovative methods for tritium inventory measurements are developed. It concerns a new autoradiography technique based on SiPM detectors with high gain, high photodetection efficiency and low bias voltage. Regarding Nuclear Reaction Analysis, measurements were carried out on tritiated tungsten samples. A small but measurable tritium signal was obtained. Concerning Laser Induced Breakdown Spectroscopy, mono ps and double ps-ns pulse tests have been performed. The hydrogen signal was not strong enough to determine the hydrogen concentration in the sample. New samples were prepared with higher hydrogen loading.
Modelling tools needed to assess the tritium inventory/migration in reactors or processes are also studied. The comparison of KUTIM and EcosimPro codes has given positive results. Good consistency is found in the results for both codes and a response similar to the first sensitivity study. ""The First workshop on Tritium Transport Modelling in Nuclear Fission and Fusion"" and a ""Workshop on online tritium detection techniques"" have been organized.
Some studies are aimed at improving knowledge of the environmental consequences in the event of contamination by tritiated products. TRANSAT work is focused on stainless steel and cement particles that are produced in dismantling activities and especially on the ‘inhalable’ granulometric fraction of aerosols. Preparation of tritiated particles was undertaken with the characterization of their physical-chemical stability in media used by biologists. The behavior of tritiated stainless steel particles in a freshwater environment was for the first time addressed. The analysis of water shown that all the tritium detected is dissolved i.e. released by the insoluble particles. Toxicity and accumulation studies were conducted on marine bivalves exposed to hydrogenated steel particles and results showed that no DNA damage was induced.
Waste management and decommissioning issues surrounding tritium are also tackled by TRANSAT. Decommissioning plan for a facility containing NaK and T tritium getters has been proposed with a technical solution that will be implemented (not part of TRANSAT). The accuracy of standard measurement techniques for tritium in soft waste was adressed. Later on, the permeability to tritium of proposed waste drum container materials was looking at . A detailed tritium permeation experiment rig was proposed and it is under commissioning.
The project logo, website, templates were first developed for the TRANSAT visual identity. Then, our activity was devoted to disseminate the TRANSAT results at various meetings, workshops and conferences. The First Tritium school was organized with 63 participants from worldwide attendance.
The efficient TRANSAT coordination insure the managing of contractual and financial issues, the maintain of project management tool and the reporting to the European Commission. In the last period, the following achievements were met: the monitoring of the impact of COVID-19 on TRANSAT, the management of review meeting with the PO and external experts, the organization of the consortium meetings (Paris in October 2019, online meeting in November 2020) and the organization of eleven TRANSAT ExCom to discuss project progress and outstanding issues."
TRANSAT contributes to the solution of a number of key issues in the management of tritium in fission and fusion facilities that will satisfy regulatory requirements and thus minimise environmental and possible subsequent health effects.
Concerning Tritium release mitigation, TRANSAT aims at expanding the body of knowledge in the field of technical solution to mitigate the tritium release. New permeation barrier concepts and effluent detritiation treatments will be available at a TRL (~5) that generates trust in the technology and require limited development for industrial scale. Furthermore, improvement in tritium permeation and inventory modelling in fusion/fission facilities is also a key outcome of the project that will help stakeholders to assess the tritium distribution in their process and thus identify where mitigation systems should be envisaged.
Tritiated waste management faces several issues like tritium mobility and uncertainty in the assessment of tritium inventory. The impact of TRANSAT project will benefit the nuclear waste producer, nuclear waste repositories and nuclear safety authorities. By developing new confining drums concepts and innovative tritium inventory measurement or assessment methodologies, the TRANSAT project will improve the strategies for safe tritiated waste management at European and International levels. From TRANSAT project results, recommendations in the field of tritiated waste management will be published that could lead to new regulation policies.
TRANSAT project is expanding the body of knowledge on tritium and to further enhance regulatory oversight of tritium-related activities, especially wherever tritiated particles are expected. TRANSAT project contributes to increase the accuracy of internal dosimetry for tritium and to improve the protection of human health from potential exposures to tritiated materials by means of contribution to preparation of new standards and regulations.
Group Photo at Kick-off Meeting in Brussels