UPDATE 1-S.Africa's Eskom expects 2021 replacement of generators at nuclear plant

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CAPE TOWN, Sept 10 (Reuters) - South African power utility Eskom said on Thursday it was on track to install six new steam generators at its Koeberg nuclear power plant in 2021, with the first already in transit and expected to arrive in Cape Town later this month.

The 4.3 billion rand ($258 million) project, which was unsuccessfully challenged in court by Westinghouse following its award to then French rival Areva, is seen as crucial for South African attempts to prolong Koeberg’s operations.

The original generators, which have U-tube piping susceptible to cracking, are heat exchangers used to convert water into steam from heat produced in a nuclear reactor core.

Africa’s only commercial nuclear power plant situated close to Cape Town, Koeberg has two pressurised water reactors generating around 1,940 megawatts of power and in operation since 1985.

“We are on track and progressing according to plan for installation during the next unit 1 and 2 outages,” said an Eskom spokeswoman.

“Three steam generators have been completely built and the remaining three for Koeberg Unit 2 are progressing well, even given the Covid-19 pandemic and consequences on productivity,” the spokeswoman added.

It is anticipated that the first set of generators will be replaced in February next year and the second set in September 2021 during scheduled refuelling maintenance, with each unit potentially offline for four months.

Each weighing around 366 tonnes, the generators are being assembled in China before shipped across to South Africa and then transported on flat-bed trucks to their destination.

The old radioactive generators will be stored in a temporary site at Koeberg, Eskom said, before being finally disposed of underground “as complete and sealed units” at South Africa’s remote Vaalputs radioactive storage facility in the Northern Cape. (Reporting by Wendell Roelf; Editing by Jan Harvey and Elaine Hardcastle)