Periodic Reporting for period 2 - PASCAL (PROOF OF AUGMENTED SAFETY CONDITIONS IN ADVANCED LIQUID-METAL-COOLED SYSTEMS)
Reporting period: 2022-05-01 to 2023-10-31
The main goal behind the Lead Fast Reactor technologies is to secure the role of nuclear energy in Europe's pursuit of a sustainable and low-carbon future. The advanced nuclear reactors ALFRED (demonstrator) and MYRRHA (irradiation facility) - both using a liquid metal as a primary coolant - will be essential milestones to foster this objective. The EU-funded PASCAL project will support the ongoing pre-licensing processes of ALFRED and MYRRHA, benefitting from continuous advice offered by a dedicated external board of experts from regulatory bodies and industrial stakeholders. The project will ultimately strengthen the longstanding collaborations amongst European organisations and strongly support the education and training of a new generation of experts to secure a safety culture is preserved.
The PASCAL project is devoted at significantly contributing to the advancement of the safety research on innovative heavy liquid metal cooled reactors, with the ambition to generate evidence that is ready-for-use in the discussions between the ALFRED and MYRRHA designers and the respective safety authorities in the pre-licensing phase.
The goals of PASCAL also set an ambition of relevance and quality to the results, which is reflected in structuring and organizing the proposal. Relevant experiments in representative conditions are planned, and - wherever applicable - accompaigned by simulations with the objective of extending their domain of validation and reducing uncertainties.
The selected activities all address the main reference: supporting the justification of resilience to severe accident conditions, aiming to demonstrate the claim that no off-site emergency measures are needed for an HLM-cooled system.
Finally, the project will strengthen the longstanding collaborations among European organizations, and will strongly support the education and training of a new generation of experts, to secure safety culture is preserved.
The PASCAL project is devoted at significantly contributing to the advancement of the safety research on innovative heavy liquid metal cooled reactors, with the ambition to generate evidence that is ready-for-use in the discussions between the ALFRED and MYRRHA designers and the respective safety authorities in the pre-licensing phase.
The goals of PASCAL also set an ambition of relevance and quality to the results, which is reflected in structuring and organizing the proposal. Relevant experiments in representative conditions are planned, and - wherever applicable - accompaigned by simulations with the objective of extending their domain of validation and reducing uncertainties.
The selected activities all address the main reference: supporting the justification of resilience to severe accident conditions, aiming to demonstrate the claim that no off-site emergency measures are needed for an HLM-cooled system.
Finally, the project will strengthen the longstanding collaborations among European organizations, and will strongly support the education and training of a new generation of experts, to secure safety culture is preserved.
In order to achieve its fundamental objective, of "paving the way to the future licensing of LFRs and ADSs", PASCAL stands on the ambitious plan of performing high-quality and high-fidelity experiments, providing either direct information to substantiate safety claims for licensing, or matter to validate numerical codes and methods in use for the safety assessment of ALFRED and MYRRHA: the two demonstrators of the LFR and ADS and the top ranking systems in the priority list of the European Sustainable Nuclear Industrial Initiative (ESNII).
According to this plan, having experiments as a backbone, in the first 18 months all activities in every PASCAL work package were made to conceive and prepare the experiments at best.
Extensive literature review provided the essential information for the studies that will be performed on the fuel system, including the identification of the most appropriate simulant for the JOG phase, whose interaction with Lead will be experimentally characterized.
Dedicated models were developed and calibrated, and pre-test analyses conducted, in support of the design of the thermal-hydraulic experiments on the safety of the reactor coolant system, recognizing the early intervention of numerical analyses as an asset for the experiments to maximize their effectiveness in addressing the phenomena of interest.
The mechanisms of formation of aerosols were experimentally investigated. In parallel, a parametric and sensitivity investigation was made on the numerical models that contribute to the analysis of aerosol dispersion. The combination of the experimental results and of the outcomes of the sensitivity study are used to inform the preparation of dispersion and deposition experiments of aerosols.
Pre-test modeling was also extensively used in the preparation of the experiments devoted to confirming the resilience of design choices. The vibratory phenomena potentially challenging the integrity of key structures were analyzed, and the test sections designed so to maximize the ability to capture them, thus to retrieve information for the proper design of these key structures.
Cross-cutting with all technical activities, the rules and procedures for proper communication, dissemination and exploitation of results, as well as for effective education and training, were established inside of the consortium.
According to this plan, having experiments as a backbone, in the first 18 months all activities in every PASCAL work package were made to conceive and prepare the experiments at best.
Extensive literature review provided the essential information for the studies that will be performed on the fuel system, including the identification of the most appropriate simulant for the JOG phase, whose interaction with Lead will be experimentally characterized.
Dedicated models were developed and calibrated, and pre-test analyses conducted, in support of the design of the thermal-hydraulic experiments on the safety of the reactor coolant system, recognizing the early intervention of numerical analyses as an asset for the experiments to maximize their effectiveness in addressing the phenomena of interest.
The mechanisms of formation of aerosols were experimentally investigated. In parallel, a parametric and sensitivity investigation was made on the numerical models that contribute to the analysis of aerosol dispersion. The combination of the experimental results and of the outcomes of the sensitivity study are used to inform the preparation of dispersion and deposition experiments of aerosols.
Pre-test modeling was also extensively used in the preparation of the experiments devoted to confirming the resilience of design choices. The vibratory phenomena potentially challenging the integrity of key structures were analyzed, and the test sections designed so to maximize the ability to capture them, thus to retrieve information for the proper design of these key structures.
Cross-cutting with all technical activities, the rules and procedures for proper communication, dissemination and exploitation of results, as well as for effective education and training, were established inside of the consortium.
In order to guarantee that the expected results will overcome the state of the art, and enable relevant advancements in securing the safety of future advanced reactors, the proper design of the experiments is mandatory. During the first reporting period, due care was given to the thorough investigation of the underpinning phenomena, and to the proper design of the test sections so to magnify such phenomena to materialize with the highest fidelity.