[Desdemona]

The power capacity over there is limited anyway (and DC besides), but the plants are on the rivers and with a drought and higher temps, there's less water and it's hotter. The article explains that the nuclear plants use river water to cool the reactors.

You get the idea that this wasn't anticipated.....

[Vesuvian]

D'oh, didn't see that part. That's what I get for posting under the influence of football.

Looks like the fell into the trap of "That could never possibly happen therefore we don't have to plan what to do when it does because it won't." So when that event does occur everyone runs around doing their best Chicken Little impersonation.

[meyer]

The power capacity over there is limited anyway (and DC besides), but the plants are on the rivers and with a drought and higher temps, there's less water and it's hotter. The article explains that the nuclear plants use river water to cool the reactors.

Well, the power over there is AC, actually. Generally 50 cycle AC as opposed to 60 that we use here. Their florescent lights flicker a little more than ours. :)

Anyway, the cooling issue is important, as you say - the steam, once its given up most of its thermal and mechanical energy in the turbine needs to be condensed back into water to be pumped back into the boiler (or reactor in the nukes), but the cooling isn't as effective when the cooling water is warmer (and especially when there's less of it). Many coal and nuke generators are de-rated in the hotter months, as are turbine engines which rely on cooler, denser intake air for their combustion. I've seen reductions of 10-15% on some generators. France's system, A/C load notwithstanding, wasn't built with 100 degrees in mind.