Hey guys, its my first posting so take it easy on me

I was wondering if you could help me. I am in my penultimate year at university studying for an undergraduate masters in Biomedical Sciences. I have been very interested in the aviation industry for a while now since I was a member of the ATC when I was 12. I appreciate the need to start organising some work experience before I apply to the trainee ATCO scheme to help me gain a better insight into how things work. However when I did contact NATS they said it is not necessary and due to the high security levels isn't even possible! If this is the case how then do you go about showing your commitment to a career as an ATCO or even if you will enjoy the role? I will therefore be greatful if someone could please advise me how to go about organising some work experience this summer after my exams are finished - if it is even needed at all? Any information related to this will also be greatly appreciated. I wait in anticipation of your responses.
Kind regards,
Brendan