Twice I must leave African country, land rejected as a test site (3,6)
I believe the answer is:
los alamos
'a test site' is the definition.
The definition suggests a singular noun which matches the answer.
'twice i must leave african country land rejected as' is the wordplay.
I cannot really understand how this works, but
'i' could be 'a' and 'a' is found within the answer.
'leave' could be 'lam' (lamming is a kind of leaving) and 'lam' is found within the answer.
'as' could be 'so' (I've seen this in other clues) and 'so' is found in the leftover letters.
The remaining letters 'los' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for los alamos that I've seen is " research centre".)