Surface Nuclear Reactors – Neutronics I
Description:
Effects of a solid ZrH moderator on the performance of a space nuclear reactor
The aim of the work will be to evaluate the moderation effects due to ZrH on the neutronic performance of a space nuclear reactor. Firstly, the moderation ratio will be studied to determine the solution that guarantees the maximum compactness core. In addition, the reactivity coefficients of fuel and moderator will be calculated as a function of burnup. Finally, the effects on reactivity and power distribution due to hydrogen dissociation with increasing temperature and irradiation will be analyzed.
Duration
6 months
ENEA Tutors
F. Lodi, R. Pergreffi
Surface Nuclear Reactors – Neutronics II
Description:
Use of burnable poisons with TRISO fuel in a space nuclear reactor
The aim of the work will be to determine a set of burnable poisons to be used with TRISO fuel in a space nuclear reactor characterized by an epithermal spectrum. For all materials deemed most promising, a neutronic characterization will be carried out to determine their effect on some key parameters such as reactivity swing, residual reactivity penalty, neutron spectrum, spectral index and the main temperature reactivity coefficients.
Duration
6 months
ENEA Tutors
F. Lodi, R. Pergreffi
Surface Nuclear Reactors – Neutronics III
Description:
Effects on reactivity of fuel compact modelling in a space nuclear reactor
The aim of the work will be to evaluate the impact on reactivity of fuel compact modelling in a space nuclear reactor. For this purpose, heterogeneous geometrical representations of the fuel compact will be compared with appropriate homogeneous solutions. In the case of heterogeneous modelling, the effects and problems associated with the use of infinite lattices of fuel kernels in which parts of these kernels are truncated by cylindrical or spherical surrounding geometries will also be analyzed.
Duration
5 months
ENEA Tutors
F. Lodi, R. Pergreffi
Surface Nuclear Reactors – Thermal Engineering I
Description:
Validation of an OpenFOAM thermal model of a sodium heat pipe for SNRs applications
Surface Nuclear Reactors require high reliability of operation due to the fact that maintenance is difficult to perform, and energy can be considered a vital asset for crew survival. Due to this end, one of the most explored solutions for heat removal from the core is sodium heat pipes, thanks to their intrinsic reliability and the absence of moving mechanical parts.
The work will fine-tune a thermal model of a heat pipe based on the OpenFOAM CFD platform and the characteristics of heat pipe of interest. The model will then be compared with available experimental data to retrieve its accuracy and inform further fine-tuning.
Duration
5 months
ENEA Tutors
F. Lodi, R. da Via
Surface Nuclear Reactors – Thermal Engineering II
Description:
Optimization of the thermal model of a TRISO fuel compact for SNRs applications
Due to the mass and volume requirements of Surface Nuclear Reactors, complex shapes are typically foreseen for the fuel (called fuel compact) arrangement in order to optimize the system. Furthermore, the use of TRISO fuel, a highly heterogeneous ensemble of micrometers particles, increases complexity due to the coupling of the micrometer (particle) and millimeter (compact) scales.
The work will focus on the creation and optimization of a thermal model to properly capture the fine features of TRISO fuel, allowing a correct prediction of the fuel temperature
Duration
5 months
ENEA Tutors
F. Lodi, R. da Via