An unpleasant task fencing silver in Alaskan city (9)
I believe the answer is:
anchorage
'alaskan city' is the definition.
(I've seen this before)
'an unpleasant task fencing silver' is the wordplay.
'unpleasant task' becomes 'chore' (I've seen this before).
'fencing' is an insertion indicator (to fence can mean to contain or put a limit round).
'silver' becomes 'ag' (Ag is the chemical symbol for silver).
'chore' going around 'ag' is 'chorage'.
'an'+'chorage'='ANCHORAGE'
'in' is the link.
(Other definitions for anchorage that I've seen before include "where you might fnd a refuge" , "Where boats may be moored" , "place to moor vessel" , "Largest city in Alaska" , "road" .)