Community Research and Development Information Service - CORDIS

H2020

SESAME Report Summary

Project ID: 654935

Periodic Reporting for period 1 - SESAME (thermal hydraulics Simulations and Experiments for the Safety Assessment of MEtal cooled reactors)

Reporting period: 2015-04-01 to 2016-09-30

Summary of the context and overall objectives of the project

The project is based on three main pillars:
1) Development and validation of advanced numerical approaches to be used in an engineering environment. The specific features of the liquid metal fast reactors require numerical simulation approaches different from the conventional ones. Indeed the mechanism related to the turbulent energy transport and the turbulent momentum transport are strongly different in liquid metal, against the strong similarity recognized in water. Moreover the large variation in spatial scales occurring in a liquid metal fast reactor thermal-hydraulic system requires different numerical simulation approaches.
2) Achievement of a new or extended validation base by creation of new reference data by experimental data or high fidelity numerical reference simulation data. The project foresees to create new reference validation data for the assessment of thermal fluctuations & flow induced vibrations in the core, the pool or the system, core & pool thermal-hydraulics, integral system thermal-hydraulics.
3) Establishment of best practice guidelines, Verification & Validation (V&V) methodologies, and uncertainty quantification methods for liquid metal fast reactor thermal-hydraulics. The project aims at establishing best practice guidelines to create physically sound simulation models for system thermal-hydraulics, Computational Fluid Dynamics (CFD), and multi-scale approaches.

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

• WP1: Fluctuations and Vibrations within SESAME project contributes to the main objectives of the project regarding the development and validation of numerical approaches for the safety and the design of next generation liquid metal cooled reactors. The work is performed along two streamlines: i) fluctuations and ii) vibrations. For the fluctuations part, 1 experiment and 4 high fidelity reference databases are foreseen to be generated for mixed and forced convection flow regimes.
• WP2: Core thermal hydraulics work package contributes to the development and validation of numerical approaches for the safety and the design of next generation liquid metal cooled reactors. Next generation liquid metal reactors can be used for transmutation consequently, hazardous nuclear wastes can be reduced. Nine partners of different institutions are involved.
• WP3: With regards to the pool mixing experimental activity, the experiments simulating loss of flow accident on CIRCE facility have been successfully making available a unique set of data for post-test analysis and code validation. The set-up of facility TALL-3D is going ahead and the experimental campaign on transient phenomena of pool mixing and stratification, driven by a competition between the heat and momentum sources , will be performed in 2017.
• WP4 is an experimental work package of the project with the following main objectives: to provide reference data for a reactor-scale safety transient in a pool-type SFR exhibiting strong 3D effects, to experimentally investigate flow behaviour in all flow regimes and specifically the transition from forced to natural circulation regime as consequence of a protected loss of flow accident in a different scales of HLM pools, to provide experimental data for the validation and benchmarking of numerical codes (i.e. system, coarse mesh CFD and CFD, coupled codes) on heavy liquid metal pools and loops.
• WP5: The aim of WP5 is to validate integral models of liquid-metal reactors using the experimental data provided by WP4. The planned activities include both system-scale models (using system thermal-hydraulics (STH) codes) and coupled models, where a computational fluid dynamics (CFD) calculation interacts with the STH model in order to provide a finer description of part of the experiment. WP5 is divided into four tasks, with each of them covering the validation activities on a given experiment. In all the tasks, activities have been organized under the form of benchmarks.
• WP6: WP6 deals with guidelines, education and dissemination. Activities related to these three topics have been carried out during the first period. Concerning guidelines, two workshops have been organised in July 2016 on the topics of Verification and Validation, Uncertainty Quantification and Best Practise Guidelines for CFD simulations of liquid metal flows.
• WP7: In the initial phase of the project, work was dedicated to the setup and the development of tools addressing the collaborative and technological objectives of the project. In parallel, efforts were made to establish the communication framework between partners.

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)

SESAME is acting as a coordinated R&D programme for nuclear thermal-hydraulics reactor safety, supporting both future reactors and the continued safe operation of existing nuclear plants.To achieve the goal, the project will maintain and develop the necessary supporting research infrastructures, such as experimental facilities and numerical tools. Specifically, it allows to collect and employs available liquid metal laboratories and facilities in Europe, like e.g. the existing facilities from KALLA, KASOLA, CIRCE, TALL, NACIE, and the Phenix sodium fast reactor. In addition, also new facilities have been constructed in SESAME.
In the short term, SESAME will provide the knowledge basis for liquid metal fast reactors (specifically, an SFR like ASTRID, or LFRs like ALFRED, MYRRHA, and SEALER) and for contemporary light water reactors which will support not only European reactor designers, but also the regulatory bodies and technical support organizations. This knowledge base will allow the EU and the member states to develop robust safety policies with respect to nuclear reactor safety. The new experimental data and the advanced simulations approaches developed within SESAME will further support the interaction with stakeholders at large and the civil society on nuclear reactor safety.
In the medium term, the SESAME project will improve the safety of liquid metal fast reactors and contemporary light water reactors, first of all in Europe, but eventually globally by making available new safety related experimental results and improved numerical approaches. These experimental results and numerical approaches will allow system designers to improve the safety relevant equipment of their reactors which will finally lead to an enhanced safety culture.
The SESAME project will reinforce the strong EU leadership in reactor design, both for liquid metal reactors and for light water reactors, and will maintain the European cooperation on nuclear safety approaches which has been established in preceding European framework projects. In so doing, the EU will remain at the forefront of the development of innovative liquid metal fast reactor designs by improving their safety characteristics, but also by improving the safety characteristics and evaluations of contemporary light water reactors.
Finally, the achievements of the SESAME project, which are stressing the safety aspects of innovative reactor, will provide the technical background to change the negative opinion and contribute to a positive opinion, and will permit reconnection with a positive public opinion, which will be required for the future development of nuclear energy.
Record Number: 196271 / Last updated on: 2017-03-28