The following information is useful to gain more detail on what is happening and the general layout of the UK National Grid and generators and interconnectors connected to it:
Currently the UK has four interconnectors connecting it to France, Holland, Northern and Southern Ireland.
One company currently operate Britains nuclear fleet: This page give the current operational status.
I have added a downloadable data file for those interested in the predictability (or otherwise) of wind performance. You can view the data here.