I sure hope you don't make safety critical decisions. If you look at the history of failures in modern complex systems you almost always see that it happens as

I sure hope you don't make safety critical decisions. If you look at the history of failures in modern complex systems you almost always see that it happens as a series of unlikely events (or events that someone deemed impossible), that let to catastrophic failure. That's the whole point of multiple safety mechanisms, have backups in case one fails. If you start removing the backup mechanisms (e.g. through improper maintanance like it is the case here) you reduce the overall safety of the system. Does that mean certain catastrophic failure in case the system is needed? Probably not, but it increases the likelyhood of a chain of events that lead to it. The main news here is not that they had cracks in the pipes, the main news is that over the last 20 odd years the operator never bothered to do a proper fix instead opting for the (likely cheaper) quick fix.