A lot of money is required for providing nuclear power (4)
I believe the answer is:
pile
'a lot of money' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for pile that I've seen before include "large amount of money" , "A heap or stack" , "Fortune" , "Post" , "lot of money" .)