Power relations? (7,6)

'power relations?' is the definition.
The definition and answer can be both groups as well as being singular nouns.
Maybe they are linked in a way I don't understand?

'power' is the wordplay.
I cannot quite understand how this works, but
'power' could be 'nuclear' (nuclear power is a kind of power) and 'nuclear' is found within the answer.
The remaining letters 'family' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?