In the wake of the severe water shortages in and around Cape Town, Eskom’s Koeberg nuclear power station has launched a mobile groundwater desalination plant which will take care of the station’s water needs.
The temporary groundwater desalination plant has a 920 kilolitre-a-day capacity. The high-quality potable water will be used for process purposes, as well as for use by Koeberg staff and contractors in the buildings and areas within the power station’s direct water reticulation network.
“The desalination plant is part of Koeberg’s three-pronged water management strategy to address the current water shortages in the Western Cape, while ensuring that the plant is able to provide safe and sustainable electricity,” said Koeberg power station manager Velaphi Ntuli.
He told journalists at the launch of the plant, on Wednesday, that the plant formed part of Koeberg’s water resilience strategy. He expected the plant would positively contribute to the efforts of the City of Cape Town in saving water, help the power station to continue to safely operate, and lessen the impact of a possible Day Zero for both staff and contractors. The plant would be able to be independent of the City of Cape Town’s water supply.
Water for the plant is being drawn from a borehole system on the Koeberg grounds. The desalination process extracts dissolved minerals and other impurities from the groundwater.
Project engineer Robert Moffat said water had been drawn from ten boreholes which were between 25 m and 32 m deep in sandy soil. He said there was a constant flow of water to the groundwater desalination plant, which was put into operation for the first time on Wednesday.
Over the years, the untreated groundwater from the aquifer has been used to support nature conservation, as well as training of firefighters at the Koeberg Fire Training Centre.
Koeberg, which is Africa’s only nuclear power station, has an installed capacity of 1 860 MW. It provides 50% of the Western Cape's energy needs and about 5.6% of South Africa’s energy needs.
The power station can only operate for about two weeks without off-site potable water. Ndlovu said the desalination plant was important to ensure continuity of supply.
He added that Koeberg had made great strides in saving water since June 2017.
“We have realised savings of 30% and have contributed positively to the city. We have saved approximately 115 000 kilolitres since June 2017, compared to the previous averages. This equates to the City of Cape Town supplying 10.5 kilolitres of water to about 11 000 houses for a month.”
Ndlovu said Koeberg would continue to drive down water consumption while also keeping its water tanks full in case of emergencies.
Koeberg said it also saves 22-billion litres of fresh water a year as its condensers are cooled by means of sea water, which is returned to the sea after use.