Parson goes round a nuclear establishment (7)
I believe the answer is:
reactor
'nuclear establishment' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'parson goes round a' is the wordplay.
'parson' becomes 'rector' (synonyms).
'goes round' indicates putting letters inside.
'rector' going around 'a' is 'REACTOR'.
Can you help me to learn more?
(Other definitions for reactor that I've seen before include "Provider of nuclear power" , "Creator (anag.)" , "device that's energy-producing" , "power supplier" , "nuclear vessel" .)