| dc.description.abstract | The Pebble Bed Modular Reactor (PBMR) is one of the alternative generation options
that Eskom is currently investigating to replace their old coal-fired plants. The PBMR
plants are smaller than conventional plants and therefore require a smaller lead time
to construct. If successfully demonstrated, the plants could comprise 20 % of the countries
nuclear build programme.
The flow of fuel spheres through the Reactor Pressure Vessel (RPV), a vertical cylinder
with height 27 m and diameter 6.2 m, determines the energy level in the RPV. If the
flow paths of these fuel spheres are known, reactor geometries can be optimised. Currently
the flow paths of the spheres are either estimated based on previous results from
different reactor geometries, or simulated using PFC-3D simulation software, based on
spherical models that doesn’t correspond to the actual spheres. A system able to accurately
track the spheres through the RPV will enable further research to be done into
the flow of the spheres.
In this research we aim to develop a concept system that could be used as the base for
a system that can track objects accurately in a confined space. Such a system could be
used to track the flow of the spheres through a model of the RPV.
During our literature study on tracking systems we found that it is hard to compare
different tracking systems with each other, due to the diversity in the applications of
these systems. We found a few surveys and taxonomies, but these were confined to
specific application domains, and thus couldn’t be used to characterise and classify
systems outside of the domain. Based on our need to compare different systems from
different application domains with one another we developed a characterisation and
classification method based on the basic aspects of tracking systems identified during
our literature study. The method enables the characterization and classification of a
tracking system to a general form. Using this method enables us to compare systems
from various different application domains.
The concept system is developed based on radio interferometric positioning. We derive
a mathematical model for the concept system and use this model to implement
an ideal deterministic simulation of the system. We use the simulation and follow an
empirical investigation to determine the effect of certain parameters on the accuracy of
the system. The results obtained with these simulations are then used to make recommendations
concerning the setup of the concept system. Using these recommendations
as inputs, a simulation is done for a set of 20 random positions. The maximum localization
error made during the simulations was 6.5 mm, much smaller than the 3 cm
resolution required by the system. This implies that the concept system is a viable
option for tracking the spheres through the RPV model. | |
