They're experiencing the flip side of the argument of picking one standard reactor and building lots of them identically. If an issue is identified, it can affect your whole fleet. In this case, they were doing an inspection and found unexpected corrosion in a safety system. They checked another similar reactor and found it too. The more they started checking the more they found. So they have to go down for extended outages and repairs, as necessary. This is very bad timing, considering the gas-driven energy crunch.

The repairs can be done, and the reactors will come back online, it just takes time. Very unfortunate, to say the least.

Kind of like those Takata airbag recalls, I suppose.