Koeberg has disgraced itself. It has just shown almost unbelievable incompetence, as if its senior management does not know what it is doing.
I must emphasise that this blunder presents no danger at all either to Koeberg workers or to the local public. This is not a safety matter, but it is an operational matter, and it hurts all the more since Koeberg up to now has had a good operational record.
It is the best power station in South Africa and, where the coal stations have been failing all the time, resulting in blackout after blackout (sorry! load-shedding after load-shedding), Koeberg has been quietly producing large amounts of cheap, clean, reliable electricity. It still promises to do so but it has stumbled badly.
Koeberg has two units of 960 MW each. On 18 January 2022, Unit 2 went down for maintenance and refueling (which takes place every 18 months), and also a big modification: the replacement of its three steam generators (SGs) with new ones. The replacement was decided upon in 2010. Koeberg had twelve years to prepare for this routine modification, which has been done on many similar nuclear reactors around the world.
When the French contractor, Framatome, arrived on site, they found that Koeberg had not made one of the most obvious preparations. Framatome was horrified. So the replacement has been postponed until the next outage.
The hapless Jan Oberholzer, Eskom’s Chief Operating Officer, blushing with shame, appeared in a press conference to explain that the SG replacement had been postponed so that Unit 2 could come back online before the winter peak demand. Oh, please! They knew long beforehand about the winter peak and should have timed the SG replacement to finish before it.
Most popular reactors
Koeberg uses pressured water reactors (PWRs), by far the most popular reactors around the world, with a superb safety record. The reactor itself does not make steam; it only makes hot water under pressure. The hot water goes to three heat exchangers, (SGs). Each SG is 21 metres high and has two flows. In one flow, hot water from the reactor goes in, loses heat, and goes out as somewhat cooler hot water. In the other flow, cold water goes in from the feed pumps, picks up heat, turns to steam, and goes out to the turbines that drive the generators to make electricity. The reactor and SGs are in a massively strong containment building. Koeberg’s containment buildings look rather like round blocks of flats without windows.
Koeberg, whose construction began in 1976, is a bog-standard Generation 2 PWR. It was built by the French, who then had probably the world’s most successful nuclear programme (they have lost their way recently). It was simple, reliable, successful and safe. Modifications over the years have made it even safer.
The Achilles heel in that generation of PWRs was the SGs. They suffered corrosion where the tubes meet the tube sheets. Materials engineers then designed new SGs with different steels and this solved the problems. Around the world the old SGs were cut out and replaced with new ones.
It was rather like a hip replacement: a major operation but a routine one, and very successful. Interestingly enough, Koeberg’s SGs were probably the best-performing in the world; they suffered very little corrosion and remained in good condition. This was probably because of Koeberg’s excellent water purification plant and the decision to run the reactor at 10 deg C below maximum temperature to prolong its life. However, in 2010, Eskom decided to replace them, simply as good practice and to be in step with the rest of the world. Then the blunders, and worse, began.
Last moment
Eskom went out to tender for the SG replacements. The contract was worth about R4 billion. Two companies tendered: Areva of France and Westinghouse of Japan-America. All the Eskom technical and commercial experts recommended Westinghouse, which seemed a certainty to win the award. But at the last moment, in April 2011, the Minister of Public Enterprises, Malusi Gigaba, vetoed Eskom’s recommendation on the most improbable of grounds.
They had to go out on tender again, and things got even worse, with a stench of corruption in the air (although it was never discovered who was corrupting whom). Again the award went to Areva on even more suspicious grounds. Westinghouse went to court against the award and a series of most disturbing court judgements followed.
Finally Areva got the contract and handed it over to Framatome, its nuclear engineering arm, who proceeded to make an almighty mess of manufacturing the SGs. Finally, eventually, they did manage to have made six good SG’s which they delivered to Koeberg in September 2020.
This is how you replace SGs and remove the old ones to a place of final disposal. A special team with special grinding and welding machines comes onto site. The unit is shut down and the plant prepared. Each SG has four pipes which must be cut out. The old SGs are then removed to a special building for cleaning and sealing. The new SGs are moved into position, welding preparations are made, and the SGs are welded in with robot welders.
The old SGs contain radioactive debris from the primary water of the reactor (they receive far too low radiation to cause nuclear reactions in their own materials). In the special room, the old SGs are washed out carefully to remove as much as possible of the radioactive debris, which is then separated and concentrated and put into suitable containers for final disposal. The SGs are sealed up, perhaps painted and covered. Eventually they would be taken to Vaalputs, the nuclear waste disposal site in the Northern Cape for final disposal. Vaalputs is perfectly suited for this; it is in remote desert, very stable geologically, arid, unpopulated with very low commercial value.
When the contractors, Framatome, arrived on site to do the replacement, they asked Koeberg where they had built the special building for receiving the old SGs. They gaped when Koeberg told them they had not built one. Koeberg had had twelve years to do so!
The Koeberg staff blustered something along the lines that, ‘We’ll build one now’. Framatome said something, or at any rate thought something, along the lines of, ‘You must be joking!’ After various confused meetings the replacement was cancelled, and Oberholzer had to appear red-faced before the public.
Simple shed
This special building is not a ‘containment building’, as some over-excited ‘energy expert’ described it. It is a simple shed, probably sealed from outside air and under a slight vacuum. It is just a place where the SGs can be cleaned and tidied up. That’s all. But Koeberg could not manage even that. Heads must roll. The power station manager, whoever he or she is, must be fired. It is just by very good luck that Koeberg’s SGs are still in good shape and can indeed run safely until the next outage. But the incompetence of the Koeberg staff over this cannot be ignored. There must be changes.
It gets worse. Unit 2 was shut down on 22 January; Eskom now says that, without changing the SGs, it will return to service in June. Five months for a routine refueling outage! In the USA the average such outage takes 32 days. I am told that housekeeping at Koeberg is not what it should be and that any procurement gets bogged down with endless dithering, bureaucracy and indecision.
Nuclear has advantages over coal in resisting the corruption, incompetence and racial engineering with which the ANC has wrecked the rest of Eskom. Nuclear reactor designs are standardised, so Eskom could not use a crazy new design as it did at Medupi.
Strict international nuclear regulation limits the naughty stuff that goes on at the coal stations. Nuclear operators have to pass very strict, regular exams on a nuclear simulator (similar to those for airline pilots) so that rules out appointment on skin colour or political connections alone.
But unfortunately, BEE procurement and Employment Equity does affect nuclear too. This was made worse at Koeberg, when it was decided on high that the racial proportions at Koeberg should try to be the same as those in South Africa at large, where ‘coloureds’ are 9% of the population, rather than the Western Cape, where they are 54%.
‘Absolutely horrified’
Last year Oberholzer said in public he was ‘absolutely horrified’ at the number of highly skilled and experienced technicians and engineers who were leaving Koeberg. There is a worldwide demand for Koeberg’s nuclear experts, who can earn more money abroad, but many of them are leaving without new jobs to go to.
Why are they so desperate to get out? Could one of the reasons be that whites and coloureds are made to feel not wanted? Right now Koeberg still has more skills and experience than it had in 1984, when the first unit started up, but it is a worry. Does Eskom care? Probably not, as long as their senior managers receive their bonuses for meeting their equity targets.
[Image: Paul Scott, https://commons.wikimedia.org/w/index.php?curid=11986995]
The views of the writer are not necessarily the views of the Daily Friend or the IRR
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