The EMP pulse is a well known, well researched and well known effect. Read more about it in the following article.
Some pro-nuclear power advocates may say that they will just disconnect a nuke plant from power grids during a Carrington Event. Unless the whole nuclear plant is inside a Faraday Cage, disconnecting it from the grid will make absolutely no difference. But let’s assume for a second, just for argument’s sake, that the nuclear plant is safe, and the power grid goes down for a lengthy period. What happens next?
via Super Solar Flare/Storm To Hit Earth – ‘Carrington Effect’; Up To 400 Nuclear Power Plants May Melt Down Or Explode, Just Like Fukushima, After Electrical Grid Shorts Via EMP Pulse, Lawsuits, Activism Needed To Prevent Extinction Event For All Life On Earth | A Green Road Journal