My understanding is that they eventually become unserviceable as they age, because of mechanical/structular reasons, or because the costs of servicing them is so prohibitive that they are unserviceable economically.
That they definitely have a begin, middle, and end, life cycle.
My understanding is that they eventually become unserviceable as they age, because of mechanical/structular reasons, or because the costs of servicing them is so prohibitive that they are unserviceable economically.
That they definitely have a begin, middle, and end, life cycle.
Disproven by Russia. Maybe sometimes core is replaced because it uses unsafe design by current standards like in St. Petesburg.