Coolant leak around oil cooler connection on radiator

hi guys, My 97 disco 1 v8 3.9 has developed a slight coolant leak on the radiator where the engine oil cooler bottom hose goes into the radiator.
How is the oil cooler attached to the radiator? From what I can see it appears that the nut on the outside holds it in, is there a seal to stop it leaking? And if so, can I replace it? Thanks very much. Graeme

The fitting looks like this (found this picture on line) cheers.

That looks as if it’s part of the design of the rad that the oil cooler pipe terminal passes through the coolant water jacket.
So, without dismantling and looking into how the rad with its oil cooler is constructed, it seem a case for the use of a “poxy” water proof putty to seal around the exterior of the terminal... try it and see as with luck it could be a quick fix.