When greenfags aren't screeching about Chernobyl and Fukushima, they try to deride nuclear power plants for not being able to follow the ever-changing demand for electricity. Which is much more true about their beloved renewable energy sources, but I digress. Nuclear fuel is used to heat water, and in turn that water turns other water into steam, then that steam runs some turbines. But couldn't you just reroute some of the steam to a steam accumulator, and quickly decrease the energy output that way, until the reactor itself gets less reactive? And when demand goes up you can use that excess steam to rev up the turbines until the reactor powers up again. Is there anything fundamentally wrong with just rerouting the steam? Costs are always an argument, but covering every field with solar panels and windmills is also quite expensive, and I imagine it might not be impossible to refit an existing nuclear power plant extra pipes and vessels so that it can reroute steam at a moment's notice.