> The tubular graphite bricks, each about a metre high, moderate nuclear reactions and are essential to safe operation. However, they cannot be replaced.
Can anyone comment on why they can't be replaced?
> EDF was granted permission by the regulator in the summer to relax its graphite weight-loss limit at the Dungeness reactor in Kent from 6.2% to 8% after it came close to breaching the original safety margin.
> Hinkley-B and Hunterston-B are also getting close to their higher 15% limits, too.
More information: http://www.greenpeace.org.uk/MultimediaFiles/Live/FullReport...
This does demonstrate an interesting aspect of large nuclear stations. Technical issues can remove large amounts of capacity from a grid. And as stations age the long term wear and tear make outages less predictable.