By this time next week, Eskom is likely, against the advice of some, to have shut Koeberg Unit 1 for an extended refuelling and maintenance programme that is scheduled to continue for between 180 and 200 days.

The long-duration outage is part of an Eskom plan to extend the life of the nuclear power station by a further 20 years beyond its current retirement date of July 2024.

To secure a new licence from the National Nuclear Regulator, various components across both units have to be renewed, with the replacement of six steam generators across both Koeberg units being the largest of these.

This life extension of Koeberg has been on the cards for ages, and several contracts for long-lead items, including the steam generators, were placed many years ago. Eskom continues to cite the 2010 cost estimate of R20-billion, but has acknowledged the real cost will be far higher.

As has been well reported, the programme has been anything but smooth, with the initial 2018 deadline having not been met, partly because of significant manufacturing problems in relation to the steam generators, which were initially meant to be fabricated in France, but were eventually manufactured in China.

Then, there was the failure of Eskom to complete the containment facilities required to house the contaminated Unit 2 steam generators, which led to a postponement earlier this year of that element of the unit’s overhaul. That delay to late next year pushes the completion of Unit 2’s maintenance perilously close to the mid-2024 licence-extension deadline.

Despite this far smaller scope, Unit 2, which was shut down in mid-January, was eventually returned to service only in August, and then tripped for a sustained period due to mechanical problems with the control rods.

The outage coincided with massive instability across Eskom’s coal fleet, which was amplified by a wildcat strike in June and July, adding a full stage of loadshedding each time Eskom resorted to rotational cuts to safeguard against a blackout.

The risk of loadshedding has not dissipated at all and has, in fact, intensified in light of Eskom having exhausted its diesel budget for the 2022/23 financial year. While some diesel relief has been provided, the only sustainable solution rests with a reluctant regulator.

Therefore, the extended maintenance of Unit 1, which will be followed in short order by catch-up maintenance at Unit 2, where the steam generators still need to be replaced, raises the spectre of a continuation of intense loadshedding into next year.

Energy analyst Clyde Mallinson has written to the Eskom board warning that the economic costs of the life extension are so extreme as to be “unconscionable”.

Using the regulator’s cost of unserved electricity of R87.85/kWh, and assuming persistent and erratic loadshedding of close to the 15 GW average of the past three months (rather than Eskom’s 13 GW base case), Mallinson calculates that the economic cost of the life extension will be R622-billion.

It’s a dire prognosis and one that, at the very least, should have the members of the National Energy Crisis Committee on high alert.