But nearly 70 years on, the old plant must bow to change.

Remains of the old plant can still be found today.

"The market right now does not support the cost of older plants."

But oil, even at old plants, may be hard to beat.

As a result many old plants may be retired in the next few years.

These are nuclear power stations which can run on what old plants have left behind.

Some measurements were made using older plants over a short time period, just three hours.

"This plant is pretty old, and there are many plants even older."

In the old plant, a problem could simmer for weeks.

"That is why we are now facing a situation of having to close old plants."