The first argument is not the/a PowerSet (which is the set of all sets), it's just a ListOfList or a ListOfOrdSet.

The intersection of the Power Set is of course always the empty set...

And it must be a ListOfOrdSet!

Not ordsets:

?- ord_intersection([[a],[a,b],[c,b,a]],X).
X = [].

Ordsets:

?- ord_intersection([[a],[a,b],[a,b,c]],X).
X = [a].