NEA Mandates and Structures
Expert Group on Uncertainty Analysis in Modelling
Tomasz KOZLOWSKI, United States
|Member(s):||All NEA member countries|
Under the NEA Statute
International Atomic Energy Agency (IAEA)|
|Date of creation:||30 June 2010|
|End of mandate:||30 June 2018|
Mandate (Document reference):
- Agreed at the 21st Meeting of the Nuclear Science Committee in June 2010 [NEA/SEN/NSC(2010)3]
- Revised at the 9th meeting of the Working Party on Scientific Issues of Reactor Systems [NEA/SEN/NSC/WPRS(2012)7]
- Extended as a part of WPRS activities at the 23rd meeting of the Nuclear Science Committee in June 2012 [NEA/SEN/NSC(2012)3]
- Extended and revised at the 11th meeting of the Working Party on Scientific Issues of Reactor Systems [NEA/SEN/NSC/WPRS(2014)2/REV1]
- Extended and revised at the 13th meeting of the Working Party on Scientific Issues of Reactor Systems [NEA/SEN/NSC/WPRS(2016)2]
- Extension procedure ongoing
- Mandate being reviewed ‑ procedure ongoing
Mandate (Document extract):
Extract from document [NEA/SEN/NSC/WPRS(2016)2]
Under the guidance of the Working Party on Scientific Issues of Reactor Systems (WPRS) the expert group will perform specific tasks associated with uncertainty analysis in modelling of coupled multi-physics analysis of present and future nuclear power systems. Reactor types considered include, but are not limited to the following:
- Present generation LWRs and HWRs with advanced and innovative fuels, evolutionary and innovative LWRs and HWRs.
- High temperature gas reactors (HTRs).
- Fast spectrum systems and advanced reactor systems.
The expert group will provide advice to the WPRS and the nuclear community on the scientific development needs (data and methods, validation experiments, scenario studies) of sensitivity and uncertainty methodology for modelling of different reactor systems and scenarios.
The main activity will be focused on uncertainties in modelling LWR transients. In this context the objectives will be:
- To determine modelling uncertainties for reactor systems under steady-state and transient conditions, quantifying the impact of uncertainties for each type of calculation in the multi-physics analysis, i.e.:
- neutronics calculations;
- thermal hydraulics modelling;
- fuel behaviour.
- For each of these types of calculation the major sources of uncertainty will be determined, arising from:
- data (e.g. nuclear data, geometry, materials);
- numerical methods;
- physical models.
- To develop and test methods for combining the above sources of uncertainty for each type of calculation so as to yield uncertainty assessment for the coupled multi-physics analyses.
- To develop a benchmark framework which combines information from available integral facility and NPP experimental data with analytical and numerical benchmarking:
- where available, experimental data will be used to test the individual types of calculation as well coupled multi-physics simulations.
- Complete Phase I (core neutronics) of UAM Benchmark for BWR, PWR and VVER.
- Complete Phase II (core thermal-hydraulics) of UAM Benchmark for BWR, PWR and VVER.
- Release specifications for Phase III (coupled system thermal-hydraulics/core 3D kinetics) UAM Benchmark for BWR, PWR and VVER.
- Complete Oskarshamn-2 Reactor Stability Benchmark.
- Organisation of Workshop on LWR-UAM and other EGUAM benchmarks.
- Specifications on SFR transient analysis benchmark.
- State-of-the-art Report on Natural Behaviour of Sodium Cooled Fast Reactor under Unprotected Transients as a Function of Fuel Nature and Core Size.
- Syntheses of the UAM-SFR results and Recommendations for Completion of the BEPU Process.
- Complete Phase I exercises (steady state exercises) of MHTGR Benchmark.
- Complete Phase II exercises (transient exercises) of MHTGR Benchmark.
- KALININ-3 Coolant Transient Benchmark Final Report.
- Final report on NUPEC BWR Full-size, Fine-mesh Bundle Tests (BFBT).
Once per year for the full expert group, in connection with WPRS meeting. Annual workshop on Uncertainty Analysis in Modelling in Reactor Systems, in connection with the related benchmark activities.
Links to other groups
The expert group will liaise closely with the NSC Expert Group on Multi-physics Experimental Data, Benchmarks and Validation (EGMPEBV). The expert group will work in co-ordination with the WPNCS Expert Group on Uncertainty Analysis for Criticality Safety Analyses (UACSA) and with the CSNI Group on Analysis and Management of Accidents (GAMA). The expert group will also work in co-operation with the IAEA HTR UAM CRP.