your information is outdated, as is that Wikipedia entry. I'll try to update it after this post.
The quote below is from "Nuclear Development, June 2011, http://www.oecd-nea.org/"
"Modern nuclear plants with light water reactors are designed to have strong maneuvering capabilities. Nuclear power plants in France and in Germany operate in load-following mode, i.e. they participate in the primary and secondary frequency control, and some units follow a variable load programme with one or two large power changes per day.
The minimum requirements for the maneuverability capabilities of modern reactors are defined by the utilities requirements that are based on the requirements of the grid operators. For example, according to the current version of the European Utilities Requirements (EUR) the NPP must at least be capable of daily load cycling operation between 50% and 100% of its rated power Pr, with a rate change of electric output of 3-5% of Pr per minute.
Most of the modern designs implement even higher maneuverability capabilities, with the possibility of planned and unplanned load-following fast power modulations in the frequency regulation mode with ramps of several percent of the rated power per second, but in a narrow band around the rated power level."
the above excerpt is just a small portion of http://www.google.com/url?sa=t...
I'm not sure why the URL has to be so god awful long to work, I tried to shorten it manually but it killed the link. I suppose if I could find a direct link from http://www.oecd-nea.org/ it might be shorter but I'm not in the mood to dig for it.