On the power interruptions:
Before I start my tirade here, a short disclaimer: I am not a nuclear expert and I have nothing to do with Koeberg or Eskom. I may have some of my technical terms mixed up and some of my facts not entirely correct - I encourage you to come forward with corrections if you work in the field.
The media, always on the lookout for a good story, has (as usual) failed to provide the public with the full story. Probably because it doesn’t fit their sound bytes so well or doesn’t make for an engaging story of incompetence.
In the early hours of Sunday morning, one of the coal stations in Gauteng that was supplying the national grid with 600Mw of power did a trip test, as they were concerned about some readings. The trip test did in fact trip the station, punching a 600Mw hole in the national grid. This sudden loss of power would not ordinarily be a major issue, but as you know Koeberg’s unit 1 is currently offline, leaving Unit 2 alone to take up the stress. Unfortunately, Unit 2 could not take up the slack and within 2 seconds of the northern station tripping, unit 2 at Koeberg tripped too. Another 900Mw disappeared from the national grid. 1500Mw short, is not a major issue for Eskom, but it is a problem. Eskom brought all of its standby stations online to help stabilise the grid.
Around this time, a massive bank of mist rolled into Cape Town. Power lines that have recently been caked in ash and soot from the recent spate of fires had not had a chance to be washed off by rain or other effects and the combination of the mist and caked insulators caused arcing at many power lines across the Western Cape. This was causing a massive drop in current as most of it was running to ground.
While Eskom scrambled maintenance crews to clean the lines, Koeberg desperately tried to bring Unit 2 back online to help stabilise the by now, very unstable national grid. Usually, when both Units are operational, recovering from a trip is a simple event since one Unit can draw on resources from the other (such as super-heated steam) to “kick-start” it. However, since Unit 1 was non operational, Unit 2 had to be brought to a complete shut down, before it could be safely powered up. This involves completely killing the nuclear reaction inside the reactor and “cold” restarting the core. It was at this procedure that got some newspapers talking about a cover-up and showing their ignorance.
When something like that happens (restarting the reactor), or if something gets caught in the intake basin (like a shark or something), Koeberg declares an unusual event and calls all emergency personnel and disaster management crews to the ready. Now, I know that sounds scary, but it’s purely a safety precaution (a very wise safety precaution). In case the very worst occurs, the right people are already at the plant, ready to spring into action. No frantic calls to wake up the needed people - they’re there at their posts, just in case. It’s standard operating procedure for running a safe plant.
Koeberg is currently synchronising Unit 2 and should have it back online today, ending the rolling blackouts by this evening. Unit 2 should be at full capacity again by Friday.
My point with all of this is to set a few things straight. First of all, none of this is Koeberg’s fault. The public often latches onto Koeberg as a scapegoat because it’s EVIL since it used nuclear power. Koeberg has quietly, safely and cleanly supplied the Western Cape without incident or accident for the last 20 years. I think the highly trained men and women, who work there to keep our lights on, deserve a little more thanks than we’re giving them.
If you want to blame someone, blame Eskom for not investing in building more power stations to keep up with demand. Blame them for allowing the Western Cape to become completely dependant on Koeberg.
Your comments are welcome…
hehehehe
