Technical Area 1 is devoted to improving the physical understanding and the numerical modelling of the relevant phenomena involved in Nuclear Power Plants (NPPs) incidents and accidents, increasing the capacity and comprehensiveness of the plant behaviour and enhancing the accuracy of safety margin assessment accordingly.


The main challenges identified within the TA1 are:

  • The comprehensive adoption and use of the Probabilistic Safety Assessment (PSA) for understanding and pointing out safety risks, including quantitative aspects for risk and margin evaluation, methodologies to assess shut-down states, and external events, quantification of the risk inherent to spent fuel pool, best practice for probabilistic safety assessment (PSA) application and appreciation of residual risk
  • The deterministic assessment of plant transients, mainly focussing on the improvement and validation of models and tools for plant transient analysis, including reactor physics and thermal hydraulics, design and evaluation of passive safety systems, coupled multi-physics codes, containment behaviour, and fluid-structure interactions
  • The impact of external loads (including electrical disturbances) and other hazards on the safety functions
  • The advanced safety assessment methodologies: safety margins and best estimate methods, integrating the deterministic and probabilistic safety assessments
  • The design of new reactor safety systems

Get in touch

TA leader:

Pavel Kral (UJV)


Sub-area title SA Leader Organisation Email
1.1 Data, Methods and Tools for Risk Assessment Nicolas Duflot IRSN
1.2 Deterministic Assessment of Plant Transients Pavel Kral UJV
1.3 Impact of External Loads and Hazards Arja Saarenheimo VTT
1.4 Effect of Electrical Grid Disturbances Michel Rioual EDF
1.5 Effects of Human Errors and Reliability Evaluation Gunnard Johansson ES-Konsult
1.6 Advanced Safety Assessment Methodologies Bernard Chaumont IRSN
1.7 Design of Reactor Safety Systems Juhani Hyvarinen LUT
1.8 Pre-Normative Research Harri Tuomisto FORTUM