Andre de Ruyter reveals startling details about Medupi Unit 4 explosion

Former Eskom CEO Andre de Ruyter revealed that poor planning, a lack of proper processes, complacency, and arrogance were behind the catastrophic explosion that destroyed Unit 4 at Medupi Power Station.

In August 2021, Eskom informed South Africans that an explosion occurred at the Unit 4 generator at Medupi Power Station near Lephalale.

It later emerged that the 720 MW unit was wrecked, leaving Eskom with a bigger electricity shortfall and a bill of around R2.5 billion to fix the damage.

In his book, Truth to Power: My Three Years Inside Eskom, De Ruyter provided further details of the blast and the real cause.

After visiting the scene, he said it was a miracle that no one was killed. “Steel sheets were ripped apart like paper. Massive rods snapped as if they were toothpicks,” he said.

“The cast-iron housing of the generator, several inches thick, was blown to smithereens and would have to be replaced.”

He explained that the explosion had occurred during work to pinpoint an external leak. The process involves displacing hydrogen with carbon dioxide before introducing air.

However, in this case, the air was introduced prematurely. It mixed with the hydrogen, creating an explosive cocktail which then ignited.

De Ruyter was experienced in running these tasks, and his first question to the Medupi managers was whether a permit had been issued for this process.

To his surprise, the managers told him it was unnecessary to have a permit for this process as it was a “routine activity”.

As this activity only occurred around once a year per plant, it was definitely not a routine activity, as claimed.

The next revelation was even more concerning. De Ruyter discovered that there was no Eskom procedure for the process.

“There was none, save for a copy of the original instructions from the manufacturer. Eskom had never written its own procedure,” he said.

“They had been winging it based on external instructions – and the price tag for Eskom would be more than R2.5 billion and a two-year-long loss of 720 MW of generation capacity.”

These were not the only problems. It also emerged that the manager responsible for the process decided to go home. He told his subordinates that they should continue without him.

As if it was not bad enough, the process of purging the hydrogen and replacing it with carbon dioxide and air stretched over two shifts.

“Correct procedure dictates that another permit should be issued for the handover – to ensure the new shift knows exactly what they should be doing,” De Ruyter said.

“Where a risky procedure is carried out over two or more consecutive shifts, the risks increase exponentially. Management was either unaware or didn’t care.”

The former Eskom CEO said the complacency and arrogance of the senior managers who were supposed to be overseeing this work was a cause for huge concern.

“The incident also showed the high cost of the erosion of institutional memory,” De Ruyter said.

“Like a giant oak tree that had been hollowed out by termites, Eskom was still standing, but it was brittle and could not survive a storm.”

Images courtesy of Chris Yelland.