posted 07-29-99 11:32 AM ET
Sure
! At least four method (use that you like more):Method 1 - AKA I'm evil!)
Active one (your) military unit inside the city -> Select Action... then Obliterate Base -> Confirm commit serius atrocity -> take 10+ years of economic sanction from other factions 
Method 2 - AKA The movers)
Change most of workers into talent, until the base is stagnant (zero food) and keep building - may be hurring - Colony Pod, Sea Colony Pod or Needljet Colony Pod -> After completing a Colony Pod verify that the computer doesn't rearrange workers to produce more food (keep city stagnant) -> Building the last Colony Pod confirm disbanding base (everyone is happy, no atrocity, just common exodus
)
Please note that method 2 doesn't work on easyest levels (Citizen, not sure about Specialist) of SMAC because the game set easy rule that doesn't permit to disband base building Colony pod (so you can build pod as fast as you want, without to worry about nutrient).
Method 3 - AKA Eated alive!)
Reduce the city to 1 population, undefended (attacking or using first part of Nethod 2) then put one of your growed mindworm just near the base and release it to the wild - almost sure next turn it will eat alive last thousand citizen and obliterate you base
Method 4 - AKA Lovly new lake)
Build a Planet Buster with Fission Reactor (you don't want to overkill messing too many square, do you?) -> Fire it on the city -> Keep atrocity as method one 
Hope you like the (may be long, but detailed) esplanation (and I hope also that you can understand my bad english
).