Mountain republic’s more westerly one excavated for uranium (4)

I believe the answer is:

fuji

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'mountain' is the definition.
(Mount Fuji in Japan)

I don't understand how the remainder of the clue works.

(Other definitions for fuji that I've seen before include "Sacred Japanese mountain" , "Japanese mount" , "Sacred Japanese peak" , "Extinct Japanese volcano - cherry tree" , "Japan's highest peak" .)

I've seen this clue in The Times.

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