Check uranium found in part of mine (5)
I believe the answer is:
audit
'check' is the definition.
(an audit is an examination or check)
'uranium found in part of mine' is the wordplay.
'uranium' becomes 'U' (U is the chemical symbol for uranium).
'found in' indicates putting letters inside.
'part of mine' becomes 'adit' ('adit' is part of 'mine').
'u' going within 'adit' is 'AUDIT'.
(Other definitions for audit that I've seen before include "Financial inspection" , "Inspect accounts" , "Roman Aquae Sulis" , "Review firm's accounts, annual check" , "Check of books" .)