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 their preferred supplier, well-established compressor and generator hire company Rand-Air to facilitate the assignment.
Having previously supplied oil-free compressors for the containment integrated leak rate test in 2005, the decision to commission Rand-Air was as a result of previous successful project partnerships with Eskom. “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,” says Andre Hopley, Projects Lead Technician at Rand-Air.
“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 degrees Celsius in temperature of the air going into containment. We found that using heat exchangers and chillers reduce the pressure testing time by a few hours allowing us to control the air pressure distribution. The requirement for the pressure testing was minus 20 degree dew point and we managed to achieve minus 40,” Hopley explains.
Hopley adds “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, damage to the equipment inside the building could be detrimental.”
With an extensive fleet of over 700 Atlas Copco compressors and generators for hire in Southern Africa, Rand-Air is a market leader in the industry. “We are proud to report that the Rand-Air contribution to the pressure test at Koeberg was a great success,” concludes Hopley.