PROTECTUS will provide the scientific basis and validated data and tools needed to assess the safety of ageing nuclear concrete structures under severe loads, for long-term operation beyond 60 or even 80 years. The project addresses critical knowledge gaps related to alkali-silica reaction, boric acid attack in spent fuel pool systems, and thermo-hydro-mechanical induced ageing, including their consequences on the structural response under beyond-design-basis seismic and severe accident scenario. Through characterization, modelling and upscaling from material to structural scales, PROTECTUS will deliver validated, uncertainty-informed safety margins and fragility assessments methodologies for nuclear industry end-users, thereby giving operators and regulators the defensible technical basis needed to justify safe, extended nuclear operation and support the sector’s low-carbon energy security goals.

The PROTECTUS project establishes a multi-scale scientific framework that transitions nuclear civil engineering research from localized material-degradation characterization to full structural-scale safety margin and fragility assessments under operational and beyond-design accident conditions. By combining multi-physics constitutive modeling, metric-scale experimental testing, and physics-informed artificial intelligence (AI) surrogate models, the project directly supports compliance with the European Nuclear Safety Directive (Council Directive 2014/87/Euratom) and provides a defensible technical basis for the safe Long-Term Operation (LTO) of nuclear power plants beyond 60 to 80 years.

Key dimensions of the project impact cover i) regulatory compliance and harmonized safety justification, ii) computational acceleration via AI surrogates, iii) coupled multi-hazard safety assessments, iv) economic sector-wide cost savings, v) climate neutrality and energy security, and vi) competence building and open science.

The PROTECTUS project establishes a multi-scale, multi-physics scientific framework that shifts nuclear civil engineering from localized material-evolution characterization to full structural-scale integrity, safety margin, and fragility assessments for Long-Term Operation (LTO) beyond 60 to 80 years. By combining multi-technique experimental campaigns across three physical length scales (decimetric laboratory specimens, metric structural mock-ups like the 1 m-thick ODOBA block, and decametric full-scale buildings like the VeRCoRs containment) with non-linear finite element simulations and physics-informed AI surrogate modeling, PROTECTUS replaces conservative bounding assumptions with defensible, uncertainty-quantified fragility curves for over 40 operating European reactors.

Key technical and strategic highlights include: i) Multi-scale & multi-physics integration, ii) Coupled degradation and accidental hazard assessment, iii) physics-informed AI surrogate acceleration, iv) SFP composite interface integrity, and v) Open European knowledge asset & training

VTT / CEA / SCK CEN / CTU / ZAG/ ASNR/ EDF/ FENIX TNT

9.2027 – 8.2031 (4 years)

3.5 M€

Project coordinator:

Miguel Ferreira (miguel.ferreira@vtt.fi)

Technical coordinator  

Miguel Ferreira (miguel.ferreira@vtt.fi)