Elsevier

Nuclear Engineering and Design

Volume 241, Issue 9, September 2011, Pages 3416-3426
Nuclear Engineering and Design

NURESIM – A European simulation platform for nuclear reactor safety: Multi-scale and multi-physics calculations, sensitivity and uncertainty analysis

https://doi.org/10.1016/j.nucengdes.2010.09.040Get rights and content

Abstract

Starting in 2005 with the NURESIM Integrated Project (FP6), a European Reference Simulation Platform for Nuclear Reactors called NURESIM is being developed. This development follows a roadmap which is consistent with the SRA (Strategic Research Agenda) of the European SNETP (Sustainable Nuclear Energy Technology Platform). After delivery of two successive versions during the course of the NURESIM project, the numerical simulation platform is presently being developed in the frame of the NURISP European Collaborative Project (FP7), which includes 22 organizations from 14 European countries.

NURESIM intends to be a reference platform providing high quality software tools, physical models, generic functions and assessment results.

The NURESIM platform provides an accurate representation of the physical phenomena by promoting and incorporating the latest advances in core physics, two-phase thermal-hydraulics and fuel modelling. It includes multi-scale and multi-physics features, especially for coupling core physics and thermal-hydraulics models for reactor safety. Easy coupling of the different codes and solvers is provided through the use of a common data structure and generic functions (e.g., for interpolation between nonconforming meshes).

More generally, the platform includes generic pre-processing, post-processing and supervision functions through the open-source SALOME software, in order to make the codes more user-friendly.

The platform also provides the informatics environment for testing and comparing different codes. For this purpose, it is essential to permit connection of the codes in a standardized way. The standards are being progressively built, concurrently with the process of developing the platform.

The NURESIM platform and the individual models, solvers and codes are being validated through challenging applications corresponding to nuclear reactor situations, and including reference calculations, experiments and plant data. Quantitative deterministic and statistical sensitivity and uncertainty analyses tools are also developed and provided through the platform.

A Users’ Group of European and non-European countries, including vendors, utilities, TSOs, and additional research organizations (beyond the current partners) has also been established in order to enhance the role of the simulation platform in meeting the needs of the nuclear industry, as applied to current and future nuclear reactors.

This presentation summarizes the achievements and ongoing developments of the simulation platform in core physics, thermal-hydraulics, multi-physics, uncertainties and code integration.

Highlights

► A reference simulation platform for nuclear reactor applications. ► Offering capacity for multi-scale and multi-physics computations and for uncertainty quantification. ► Developed and supported by a European united team according to a general roadmap. ► Presentation of the main achievements and future developments.

Section snippets

The objectives of the NURESIM simulation platform

The NURESIM simulation platform intends to be a European reference platform for nuclear reactor applications supported by a united European team of experts (Cacuci et al., 2006, Cacuci et al., 2007, Chauliac et al., 2009).

Main achievements and future developments in core physics (sub-project 1)

In the area of core physics, averaging the cell and nodal neutronics properties remains necessary, but the safety limits are more and more needed at a detailed scale, the pin-by-pin scale for the hottest individual fuel pellet, rod clad and coolant subchannel for whole 3D core realistic operating and transient conditions.

This is an increasingly complex issue, because the fuel assemblies in operating reactors are increasingly heterogeneous, both as fabricated non-uniform lattices, with water

Main achievements and future developments in thermal-hydraulics (sub-project 2)

The objective of the NURESIM thermal-hydraulics subproject was to develop and implement advanced thermal-hydraulics models in the NURESIM platform in order to improve the understanding and the predictive capabilities of the simulation tools for key two-phase flow processes that can occur in nuclear reactors, focussing on two high-priority issues, the Critical Heat Flux (CHF) and the Pressurised Thermal Shock (PTS).

The activity included an analysis of the PTS scenarios, a review of all basic

Main achievements and future developments in multi-physics (sub-project 3)

The numerical simulation and analysis of postulated transient scenarios require multi-physics simulation tools which couple time-dependent core neutron kinetics with core and plant thermal-hydraulics as well as thermo-mechanical models of fuel behaviour, since changes in fuel temperature and moderator density induce important reactivity feedback to the power generation. Originally, such multi-physics simulation tools offered rather approximate modelling capability. With the development of

Main achievements and future developments in sensitivity and uncertainty (sub-project 4)

Sensitivity and uncertainty analyses are of fundamental importance to reactor analysis, design, and safety. Due to imperfect knowledge of physical phenomena and data, sensitivity and uncertainty analyses must be carried out in order to supplement the results produced by computational tools used for the analysis, design and demonstration of the safety of any nuclear power plant.

Sensitivity and uncertainty analysis methods rely either on deterministic or statistical procedures. Various such

Main achievements and future developments in code integration (sub-project 5)

The NURESIM platform integrates thermal-hydraulics and neutronics European codes and solvers in the SALOME simulation framework. The integrated codes and SALOME simulation tools work concurrently within applications specified and developed by the multi-physics sub-project.

SALOME (Fig. 7) is a generic open-source platform (see http://salome-platform.org) presently developed by EDF, CEA and OpenCascade. It provides interoperability between CAD, meshing and computing codes and solvers, and to

Consortium and collaborations

The NURISP consortium consists in 22 partners from 14 European countries: ASCOMP, CEA, CHALMERS, EDF, FZD, KIT/FZK, GRS, IMPERIAL COLLEGE, INRNE, IRSN, JSI, KFKI, KTH, LUT, NRI, PSI, TUDELFT, UCL, KIT/UNIKA, UPISA, UPM, VTT; including the major European nuclear countries operating PWR, VVER and BWR (which are the focus of the Work Program). It represents an opportunity to cross-fertilize the approaches to nuclear reactor simulation from Eastern and Western European countries.

The overall skills

Conclusion

The development of the NURESIM platform has and will have long-term strategic impacts through the main following achievements:

  • development of new physical models and numerical solution algorithms of physical phenomena in neutronics (from lattice to core level), thermal-hydraulics (at the four scales represented by DNS, CFD, component and system scales), fuel behaviour under accident conditions,

  • multi-physics and multi-scale coupling,

  • quantification and reduction of computational uncertainties,

Acknowledgements

The authors wish to acknowledge the valuable guidance provided by Dr. Michel Hugon of the European Commission throughout the NURESIM Integrated Project and since the beginning of the NURISP Collaborative Project.

All the presentations of the NURESIM General Assemblies held in November 2006 in Paris and in November 2008 in Madrid are available on the NURESIM Open Web Site: www.nuresim.com.

References (46)

  • Cacuci, D.G., D’Auria, F., 2006. State of the Art Report on sensitivity and uncertainty analysis (SP4). Available on...
  • Cacuci, D.G., Aragonés, J.M., Bestion, D., Chauliac, C., Coddington P., Crouzet N., 2007. Towards A European Platform...
  • D.G. Cacuci et al.

    Adjoint sensitivity analysis procedure for reliability analysis: application to a model of the international fusion materials irradiation facility

    Nucl. Sci. Eng.

    (2008)
  • D.G. Cacuci et al.

    Global adjoint sensitivity analysis and optimization: computation of critical points

  • D. Caraghiaur et al.

    Lagrangian particle tracking as a tool for deposition modelling in annular flow

  • C. Chauliac et al.

    NURESIM: A European Software Platform for Nuclear Reactor Simulation, M&C 2009

    (2009)
  • S. Christoforou et al.

    Implementation of an Approximate Zero-Variance Scheme in the Monte Carlo code TRIPOLI4, Physor-2006, C2138

    (2006)
  • M. Coste

    New Developments in Resonance Mixture Self-shielding Treatment with Apollo2 Code; MC-2005

    (2005)
  • Coste, P., Pouvreau, J., Laviéville, J., Boucker, M., 2008. Status of a Two-phase CFD Approach to the PTS Issue,...
  • C. Debergé et al.

    Simulation of a main steam line break on VVER-1000 reactor with CRONOS2 and FLICA4 codes

  • J. Dufek et al.

    Stochastic approximation for Monte Carlo calculation of the steady-state conditions in thermal reactors

    Nucl. Sci. Eng.

    (2006)
  • Ferroukhi, H., Hollard, J.M., Zerkak, O., Coddington, P., 2007. PWR Cell Calculations using APOLLO-2 within the NURESIM...
  • M.C. Galassi et al.

    Validation of NEPTUNE CFD Module with Data of a Plunging Water Jet Entering a Free Surface

    (2007)
  • Cited by (86)

    • Envisaged future for nuclear thermal-hydraulics

      2022, Nuclear Engineering and Design
      Citation Excerpt :

      It is also recommended to further advance the application of the ML or AI technology to develop and validate NTH closure laws or surrogate models. In the last 2 decades, various multi-scale, multi-physics simulation platforms have been developed by coupling or integrating traditional system TH codes with core neutron physic, sub-channel TH, fuel thermal mechanical, component mechanical and containment TH codes, as well as severe accident modules, such as NURESIM (Chauliac et al., 2011), VERA (Turinsky, 2012; Turinsky and Kothe, 2016), and the SPACE-based integrated safety analysis system (Song et al., 2021). They can be also combined with CFD-scale and component-scale codes to predict an integrated overall behaviour of the power plants with high fidelity, such as the CUPID-based sub-channel-scale coupled code package (Song et al., 2021).

    • An efficient digital twin based on machine learning SVD autoencoder and generalised latent assimilation for nuclear reactor physics

      2022, Annals of Nuclear Energy
      Citation Excerpt :

      The typical computational time for one simulation of the whole core amounts to 30 s as reported in Argaud et al. (2018). The recent programs such as CASL (Szilard et al., 2011), NURESIM (Bradley, 2012) and NURESIM (Chauliac et al., 2011) apply different strategies to develop the next generation high-fidelity simulation tools for NPP. Many of the codes developed are finite element-based with high-fidelity model and even coupled with other codes.

    View all citing articles on Scopus
    View full text