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· Create a common ground for discussing envisaged improvements in various areas of System Thermal-Hydraulics (SYS-TH), promoting a cooperation aimed at the improvement of the TH-SYS Codes and their application in Licensing process and Safety Analysis

· Identify area of improvement and share experience on graphical user interface (GUI), SYS-TH code coupling with other numerical tools, such as 3-D neutron kinetic, fuel pin mechanics, CFD, etc.

· Share experience on code inadequacies and cooperate in identifying experiments and/or code to code benchmarks for resolving the deficiencies

· Share user experience on code scalability, applicability, and uncertainty studies

· Establish acceptable and recognized procedures and thresholds for Verification and Validation

· Maintain and improve user expertise and documented user guidelines for applying the code


FONESYS Road Map and Key-Topics

The following items have been suggested to constitute the Road Map of FONESYS for the next period (up to next WS). In addition, papers on FONESYS design and motivation have to be written and published in order to promote the initiative.

1. Virtual mass and pi terms in the frame of hyperbolicity
The state-of-the-art must be established and documented.

2. CHF benchmark
The goal is to evaluate the differences between 6-equation 1D models in different codes.

3. TPCF benchmark
The goal is to compare SYS-TH codes performance in modeling of two-phase critical flow phenomenon.

4. Comparison “drift flux – 6 equations – multi field”

The goal is to identify the justification for the evolution of system codes.

5. Transport of Interfacial Area + Turbulence models including 3D flow regimes

6. 3-field equations: experimental basis and theory

7. Extension of system codes capabilities for super-critical water, gas, sodium and lead-bismuth reactors

8. Codes portability and “mesh convergence” issues

9. Coupling between CFD and SYS-TH codes

10. Scalability of closure laws (stratification, droplet entrainment, etc.)  

FONESYS Sub-Topics

1.          Use of best-estimate system thermal-hydraulic codes for licensing

2.          Acceptability of errors in code predictions

3.          Loop seal clearance

4.          Radiation heat transfer

5.          Droplet field impact on results of the code calculations

6.          Difference between the dispersion and diffusion in numeric

7.          To clarify the meaning of convergence in time and in space

8.          Importance of 3-field equation models in system codes’ prediction

9.          Jacobian

10.        Scaling of thermal-hydraulic phenomena

11.        Reflood

12.        3-D modeling capabilities of SYS-TH codes (e.g. for thermal-mixing studies, etc.)

13.        Natural Convection

14.        Natural Circulation

15.        Dry-out and post-CHF heat transfer

16.        Critical flow, sonic velocity, effect of sharp edge cavitation

17.        CCFL