A hospital worker using long-serving Taoiseach's first name? That's never going to happen (7)

I believe the answer is:

dreamon

I'm a little stuck... Click here to teach me more about this clue!

'a hospital worker using long-serving taoiseach's first name? that's never' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'going to happen' is the wordplay.
'going' becomes 'on' (both can mean functioning or activated).
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
'happen' becomes 'dream' (I am not sure about this - if you are sure you should believe this answer much more).
'on' after 'dream' is 'DREAMON'.

Can you help me to learn more?

I've seen this clue in The Irish Times.

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