Optimising neutronics performance of breeder blankets

Jonathan Shimwell


To perform automated parametric multiphysics analysis of breeder blanket designs with an aim of optimising the design.



To perform automated parametric multiphysics analysis of breeder blanket designs with an aim of optimising the design.


Selection of design parameters

Parametric CAD construction

Neutronics simulation for TBR and EM

Converstion to unstructured mesh

Neutronics simulation for volumetric heating

Converstion to engineering mesh

Simulations to find stress and temperature

Evaluate design

    Converstion to      CGS



Demonstration parameter study

  • CAD geometry for 100 different versions of the HCPB breeder blanket was automatically produced
  • Parameters varied were
    • lithium ceramic bed height (0-60mm)
    • neutron multiplier bed height (0-120mm)
    • lithium 6 enrichment (0-100%)
    • neutron multiplier materials (Be, Be12Ti, Zr5Pb4)
    • lithium ceramic materials (Li4SiO4, Li2TiO3)
  • CAD geometry converted to neutronics models

Demonstration parameter study

  • Different geometric parameters avaiable

Demonstration parameter study

Interpolation of results

Li4SiO4 with 60% 6Li and Be


Tritium production

Li4SiO4 at 60% 6Li enrichment with Be

Energy amplification

Li4SiO4 with 60% 6Li enrichment and Be12Ti

Procedure for obtaining volumetric heating

  • Neutron and photon heating simulated and results passed to engineering codes
  • Parametric CAD models created using Python scripts and automatically converted to neutronics models
  • Unstructured mesh applied to the geometry        

Automated CAD models for different blanket geometries

HCLL blanket design with 90mm and 180mm lithium lead sections

Automated CAD models for different blanket geometries

HCLL blanket design showing cooling channels in the first wall

Additional details - cooling channels



Automated hex and conformal tet meshing

Neutronics mesh

Engineering mesh

Data mapping from hex to tet mesh

Neutronics mesh simulation results

Engineering mesh interpolated values


Fully automated hex meshing of the geometry to abaques format for use with MCNP 6 unstructured mesh

Volumetric heating

Heating values obtained on unstructured mesh that conforms to material boundaries. 



Volumetric heating



Component Be12Ti Be
Lithium ceramic 15.9 17.2
Eurofer first wall 6.2 5.8
Tungsten armour 28.1 26.4
Neutron multiplier 4.8 5.0

Heating W/cm3

with 60% 6Li enrichment

Automatically identifying regions

First wall heat flux

Coolant outlet

Coolant inlet

Current work

  • Moving simulations to the cloud. This will allow high throughput, high performance and simulation on demand.

S3 storage

Parametric DEMO reactor

18 coils

  • Magnetic equilibrium solved


  • Plasma ripple kept below limit
  • Model includes
    • poloidal field coils
    • toroidal field coils
    • gravity supports
    • intercoil connections

16 coils

  • detailed breeder blankets
    • detailed breeder blankets

Produced using an early

version of Nova by S McIntosh

Parametric DEMO reactor

 Nova Produced by S McIntosh

Parametric DEMO source

TBR Tallies in Serpent using STL geometry


  • Multi-parameter optimisation will be used to find blanket designs that merit future investigation.
  • The approach to coupling neutronics inputs to engineering simulations has been overhauled
  • Future work will include automated simulations to obtain stress and temperature of materials

L. Lu

Y. Qiu

P. Pereslavtsev

A. Haussler

F. Hernandez

C. Zeile

G. A Spagnuolo


S. McIntosh

L. Evans

T. Eade

S. Ha

S. Merriman

T. Barrett

A. Burns

J.C. Jaboulay

J Aubert

Funded by Eurofusion

Current research progress

By Jonathan Shimwell

Current research progress

CCFE student presentation 2016

  • 235

More from Jonathan Shimwell