Negative learning by doing is very easy to explain: as you go, you realise many perils and dangers of this thing that you were not aware of in the beginning, and those result in a lot of safety precautions added in subsequent projects, increasing the costs.
I begin to understand the logic behind the US derailings.
The idea here is that maintenance is much, much cheaper than rescue operations. If 100 more pumps let you run for years without a scram, go along and order them.