Abstract:
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The project consist in calculate the keff to a small nuclear battery. The code Monte-
Carlo neutron transport code MCNP is used to calculate the keff. The calculations are
done at the beginning of life to know the capacity of the core becomes critical in
different conditions. These conditions are the study parameters that determine the
criticality of the core. These parameters are the uranium enrichment, the coated
particles (TRISO) packing factor and the size of the core. Moreover it is also studied the
effect of the burnable poisons in the core and the control rods. Different
concentrations of poison are considerate and the control rods are studied in different
positions and materials. Altogether 140 criticality calculations have been made.
The report can be split in two parts. The first efforts are leaded to build the MCNP
model that reproduces the actual U-Battery in the program. The 3-D model is a reliable
reproduction of the core. Since the description of the small coated particles in the
graphite matrix that conform the fuel rods, the assembly with the fuel rods, coolant
channels and burnable poisons rods until the construction of the core with the
assembly array and reflectors. A good geometry description guarantees reliable keff
results. The second part is based in the model. To reproduce each condition in the core
to study the behaviour of keff the model is slightly modified and MCNP is run to obtain
the results.
Once the results are obtained they will be validated against similar analyses conducted
at Delft using different code suite. The study would be extended in the future to study
the burnup modelling. |