Background:Molten Salt Reactor(MSR) has several advantages over the other Generation IV reactor.Referred to the French CNRS research and compared to the fast reactor

super epithermal neutron spectrum reactor type is slightly lower and beading rate reaches 1.002.Purpose:The aim is to explore the best conversion zone layout scheme in the super epithermal neutron spectrum reactor.This study can make nuclear fuel as one way to solve the energy problems of mankind in future.Methods:Firstly

SCALE program is used for molten salt reactor graphite channel

molten salt core structure

control rods

graphite reflector and layer cladding structure.And the SMART modules are used to record the important actinides isotopes and their related reaction values of each reaction channel.Secondly

the thorium-uranium conversion rate is calculated.Finally

the better molten salt reactor core optimum layout scheme is studied comparing with various beading rates.Results:Breading zone layout scheme has an important influence on the breading rate of MSR.Central graphite channels in the core can get higher neutron flux irradiation.And more233Th can convert to233Pa

which then undergoes beta decay to become233U.The graphite in the breading zone gets much lower neutron flux irradiation

so the life span of this graphite can be much longer than that of others.Because neutron flux irradiation in the uranium molten salt graphite has nearly 10 times higher than the graphite in the breading zone

it has great impact on the thorium-uranium conversion rates.For the super epithermal neutron spectrum molten salt reactors

double salt design cannot get higher thorium-uranium conversion rates.The single molten salt can get the same thorium-uranium conversion rate

meanwhile it can greatly extend the life of graphite in the core.Conclusions:From the analysis of calculation results

Blanket breeding area in different locations in the core can change the breeding rates of thorium-uranium in the Blanket

but cannot improve the conversion rates of thorium-uranium in the uranium molten salts.For super thermal spectrum molten salt reactor

single molten salt graphite channel can provide CNRS design and almost can equivalent thorium-uranium conversion rate.At the same time

it can greatly reduce the levels of neutron flux in the moderator of graphite and improve the working economy of molten salt reactor.