Research and Development of Advanced Nuclear System        

0.050⊿keff (%)-0.05-0.1-0.15

Inner core fuelOuter core fuelRadial blanket fuelDummy fuelNeutron source

Conventional collapsing
Advanced collapsing-0.2-0.25
0Control rod 

Conventional collapsing
Advanced collapsing⊿φ(%)

10-1030

60

90

120

150

180

210-2-3

Plenum UpperblanketCoreLowerblanket

Shield40
Neutron energy group6080   
This figure shows the difference of the effective multiplication
factor (collapsing error), calculated by the conventional andadvanced collapsing method, based on the 70 energy-groupcalculation as the reference. The newly developed advanced
method gives drastically negligible collapsing error, independent
to the number of neutron energy groups (horizontal axis).

   

3220240      
This figure shows the difference of the neutron flux spatial distribution(collapsing error), calculated by the conventional and advanced
collapsing method in 18 neutron energy groups, based on the 70
energy-group calculation as the reference. The newly developed
advanced method gives improved coincidence with the reference
calculation, especially in the core peripheral region (axial blanket).

                                                                                                                                −  − 

JAEA R&D Review 2006

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