Possible creator of power (7)

I believe the answer is:
reactor
'power' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'possible creator' is the wordplay.
'creator' anagrams to 'REACTOR'.
However, I'm not sure how the anagram is indicated.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for reactor that I've seen before include "one liable to have a meltdown if things go disastrously?" , "Producer of nuclear energy" , "Heart of a nuclear power station" , "Nuclear power plant" , "source of power, perhaps" .)
