Universities Nuclear Technology Forum – University of Cambridge

18th-20th March 2009

CFD Analysis of Operating CFD Analysis of Operating Reactor Systems and a Reactor Systems and a

Proposed “Generation IV” Proposed “Generation IV” DesignsDesigns

by

S. Rolfo & A. Keshmiri

Colleagues:

D.R. Laurence, M.A. Cotton and Y. Addad

School of Mechanical, Aerospace & Civil Engineering (MACE)

The University of Manchester

Manchester, M60 1QD

www.CFDtm.org

Summary

Fuel Pins in Current AGR reactors

Code_Saturne

A proposal for next generation IV reactors: Sodium Fast Reactor (SFR) fuel assembly

Conclusions

Fuel Elements in AGRs

Various Configurations

1)Multi-start

2)Transverse

3) Hoop

4) Smooth

2-dimensional approach

Test CasesSquare Rib Profile (SRP)

Transverse Rib Profile (TRP)

Multi-Start Rib Profile (MSRP)

Turbulence models:1) Chen & Kim LRN k-ε model2) Wilcox LRN k-ω model3) Lien & Durbin v2f model

STAR-CD Results: contoursStreamwise velcity contour: LRN Chen & Kim k-ε model

Relative Pressure contour: LRN Wilcox k-ω model

STAR-CD Results: Lien & Durbin v2f model

y/k=1

y/k=0.1

STAR-CD Results: Lien & Durbin v2f model

Code_Saturne

Code developed by EdF and now open source downloadable from:

www.code-saturne.org

Unstructured

Co-located, Finite Volume Formulation

Different turbulent models (both RANS and LES)

Incompressible or expandable flows with or without heat transfer

Different modules: radiative heat transfer, combustion, magneto-hydrodynamics, compressible flows, two-phase flows

Possible coupling with Code_Aster for structural analysis and with Syrthes for thermal analysis.

Parallel code coupling capabilities (awarded the Gold medal on HPCx)

TWiki collaborative website with forum and developments: http://cfd.mace.manchester.ac.uk/twiki/bin/view/Saturne/WebHome

11

SFR fuel assembly: Case presentation Flow parameters:• P/D = 1.1 • Re = 11000 (Bulk vel = 1 m/s)• Working fluid liquid sodium

• = 847 kg/m3• µ = 2.55 10-4 Kg/m/s• Pr = 5 10-3

SFR test case

SFR test case: comparison k- and Rij

Rij (SSG)k-

Conclusions

SFR fuel assemblyPreliminary RANS calculations shows a completely

different flow field respect to rod bundle in smooth configuration (no wire).

k- and Rij SSG models give very similar results from a qualitatively point of view, but very different quantitatively

Possible LES or Hybrid RANS/LES calculationsAGR

Three different rib profiles have been tested and they all showed similar profiles for velocity, temperature and pressure.

Lien & Durbin v2f model was proved to be the best model for this test case.