The Longevity of Nuclear Power Plants Has Averaged About

The longevity of nuclear power plants has averaged about

A) 20-25 years due to unexpectedly high levels of corrosion and embrittlement.
B) 40-50 years,longer than imagined,because neutrons tend to stabilize the building materials.
C) 10 years,only about 25% of their expected life,due to the need for new government-mandated safety designs.
D) 40 years,as expected,due to routine maintenance and the replacement with new longer-lasting materials.