PhD Defense | Jonas Vande Pitte | Improved Reactor Monitoring for Advanced Neutron Irradiations | UGent
Name: Jonas Vande Pitte
Date: September 20, 2021 - 16h00 CET
Location: Faculteitsraadzaal, gebouw S2, Krijgslaan 281, Gent.
Improved Reactor Monitoring for Advanced Neutron Irradiations
To prevent the devastating effects of climate change there is a need for CO2 neutral energy sources. One option might be nuclear power. However, to extend the lifetime of our current nuclear power plants or to design new and innovative reactors critical materials such as the reactor pressure vessel are thoroughly tested in research reactors. These reactors are many times more powerful than our conventional power reactor. This way research reactors can simulate how a material will behave after many years of irradiation.
To evaluate the damage the irradiation has inflicted on the material, it is important to know the irradiation temperature. Accurate temperature measurements are possible in instrumented irradiation capsules. However, these are expensive and complex. Therefore, many irradiations are carried out in un-instrumented capsules. In this work we investigated SiC temperature sensors to provide temperature measurements for these capsules. Some improvements are put forward with regards to the capsule design to better predict the temperature after irradiation. In addition, it was shown that lattice parameter expansion can be used to determine the irradiation temperature and that there is a memory effect.
Another important parameter is the neutron spectrum or flux during an experiment. These are currently measured with activation foils. Some materials cannot be used in their pure form and must be diluted in aluminium for accurate measurements. These aluminium alloys are no longer available and won’t be back on the market for another 2 to 3 years. This work provides an alternative to this impending shortage by demonstrating activation dosimeters with nanocoatings.
Finally, for some applications such as for neutron transmutation doping of semiconductors it is desirable to alter the neutron flux or the number of neutrons at a certain location. In this work we have shown this can be done with hafnium and cadmium neutron absorbers by successfully altering the resistivity of silicon semiconductors.
Christophe Detavernier (UGent)
Johan Lauwaert (UGent)
SCK CEN mentors:
Inge Uytdenhouwen (SCK CEN)
Click here for a list of obtained PhD degrees.