Core RUC reforms take place again (7)
I believe the answer is:
reoccur
'take place again' is the definition.
('occur' can be a synonym for 'take place' so perhaps 'reoccur' is OK for 'take place again')
'core ruc reforms' is the wordplay.
'reforms' indicates anagramming the letters.
'core'+'ruc'='coreruc'
'coreruc' with letters rearranged gives 'REOCCUR'.
(Other definitions for reoccur that I've seen before include "make comeback" , "Come again?" , "Happen again" .)