Recognised as Eskom's most consistent and reliable power station, Koeberg is the only nuclear power station in Africa. Koeberg has a pressurised water reactor design. Featuring the largest turbine generators in the Southern Hemisphere, Koeberg is also the most southerly-situated nuclear power station in the world. With International Law stipulating that all containment buildings of all nuclear plants have to be pressure tested every ten years, Eskom contracted Rand-Air to facilitate the assignment.
The purpose of the pressure testing of the containment building at Koeberg was to ensure that there was no leakage which could be harmful to the surrounding environment and public.
Using ten PTS916 Rand-Air units running through desiccant dryers, dry oil-free air was pumped into the containment building. Both the inner and the outer sector of the building were surveyed before, during and after the test. Water particles have a big influence on pressure testing and the end result. We were required to match 18 °C in temperature of the air going into containment. Heat exchangers and chillers reduce the pressure testing time by a few hours allowing for control of the air pressure distribution. The requirement for the pressure testing was minus 20 °dew point - minus 40 was achieved.
The pressure test took between seven to eight hours. It took two and a half hours to reach a pressure of one bar. The procedure stops for eight hours when it reaches one bar, this is key in ensuring that everything is stable enough to continue to four bar. The process requires the go ahead from two parties namely Électricité de France (EDF) and Eskom. It is critical to monitor the progression thoroughly as damage to the equipment inside the building could be detrimental.
The pressure test at Koeberg was a success.
