SAFE-SMR will contribute to maintaining the highest level of nuclear safety, assessing the safety implications of Light Water (LW) SMR specific features, supporting safety-by-design and EUropean (EU) regulatory readiness, and strengthening EU technical leadership and independent safety review capabilities. The project is structured around three interconnected Main Objectives (MO):

• MO1 – Passive Safety Systems (PSS) performance and reliability assessment: Develop, apply, test and consolidate a reproducible methodology for PSS performance and reliability assessment based on experiments and simulations, allowing to assess functional failures and the effects of internal and external hazards on PSS operation. The methodology allows identifying representative Design Extension Conditions (DEC) scenarios and influential parameters that may trigger cliff-edge effects and derive local safety margin based on fulfilment of the PSS safety mission.
• MO2 – IVR/EVR safety margins: Develop, apply, test and consolidate a reproducible In-Vessel Retention (IVR) and Ex-Vessel Retention (EVR) (with core catcher) safety margin assessment methodology, with relevant safety criteria. It will be supported by improved Severe Accident (SA) models and computationally efficient conservative 0D tools.
• MO3 – Source Term (ST) and risk-informed Emergency Planning Zone (EPZ): Develop and demonstrate integrated ST, off-site consequence and risk informed EPZ assessment methodologies addressing preliminary conservative and Best Estimate (BE) analyses, uncertainties, siting, built environment, external hazard and multi-unit/module effects.

Scientific: Combined deterministic/probabilistic methods and improved knowledge, models and data.

Regulatory/technological: Stronger EU independent assessment, harmonization, safety-by-design and regulatory readiness.

Economic/technological: More efficient assessment and design optimization; potential support to EU nuclear industry competitiveness.

Societal: Better emergency preparedness, informed siting and public trust.

Environmental/energy: Potential support to affordable, safe and sustainable low-carbon electricity and heat, reducing climate impacts.

Education: Informing regulatory authorities and supporting the competence build-up of a new generation of trained analysts and long-term knowledge transfer.

Key advances and unique features of the project include:

• Systematic exploration of degraded and near cliff-edge PSS conditions; identification of cliff-edge threshold and local PSS safety margins;
• Development and validation of Reduced Order Models (ROMs) for reliability applications; extension of a conservative 0D tool from IVR to EVR and its release to the community;
• Integration of deterministic, uncertainty and probabilistic analyses into reproducible methodologies ready to be used to estimate functional failure and their probabilities in safety reviews;
• Identification of DEC scenarios for five SMR types;
• Application of CFD to support functional failure estimation;
• Development of methodologies for IVR/EVR safety margin assessment for SMRs and EPZ assessment.

ENEA, ASNR, EDF, FZJ, GRS, INRNE, KIT, KTH, LEI, RATEN, SINTEC, SURO, UNIROMA1, VTT, ENEN, TALTECH, NFQ, APOSS, SSTC-NRS, CIEMAT, TRACTEBEL, RUB, FRAMATOME, JRC, POLIMI, UNIPI, NCBJ, NRG PALLAS, PSI, BEL V, JSI, CNL

Project coordinator:

Fulvio Mascari (fulvio.mascari@enea.it)