If I recall correctly, one of the conditions of a nuclear generating plant staying up is that local offsite emergency response teams are available. My understanding is when natural (or presumably) man-made disasters happen in the locality of a nuke plant, they have to shut down.

What kind of local emergencies require plant shutdown?

Civil unrest/looting (on a major scale)? Terrorist activities? Ice storm?

Since the power grid stability is currently somewhat dependent on nukes, I can envision a bunch of nukes being forced offline for the above reason, which causes (due to grid instability) a cascading effect.

Or are the reserves available in January enough to make up for the (temporary) loss of some of the nukes?

Interestingly, here in Alberta January is the peak power demand season, not summer as is in the case in most of the US.

Jon

-- Anonymous, June 21, 1999