The safe operation of nuclear facilities is based on the information and control cables being capable of fulfilling their safety function even during design-based event (DBE). The nuclear cable qualification is mainly based on accelerated laboratory tests. This process is usually performed by cable manufactures according to standards. Although these examinations have been used for decades the relation between the accelerated ageing and the ageing in operation conditions are still in the focus of scientific interest.
The purpose of the thesis work is to develop a non-destructive testing method for nuclear cables. The developed method will be based on dielectric measurements. The work contains accelerated ageing test to reveal the correlation between the performance parameters of the cables and the results of the non-destructive electrical tests.
In the first part of this document concepts about aging and properties of the insulating material are exposed, to continue with concepts of aging in the insulators in electric cables and mention some tests carried out in previous research works, continuing qualitative methods for condition of monitors are described, and in the part following this a deeper approach is described for electrical techniques in monitoring conditions.
As an important part of this work, after aging and with the results obtained, linear relationships between mechanical and electrical tests are associated and defined, for example, Loss Factor versus EAB (Elongation at break), Recovery Time and Indenter Modulus. However, Return Voltage is still a parameter that is not linearly defined with the results of the mechanical tests.
Finally, the results are exposed and associated with simple concepts about the properties of insulation for the "jackets" in relation to a thermal aging process.