What is the procedure after a missed approach at the destination alternate since alternate fuel does not contain a missed app. at the alternate?
Let's assume you started exactly with ICAO minimum fuel required (as explained in What are the ICAO fuel reserve requirements?):


Taxi fuel Let's assume you used all of it at your departure airport.
Trip fuel Used for the flight to the destination airport.
Contingency fuel Let's assume this was used in a holding pattern at the destination.
Alternate fuel Used for a go around at the destination and the subsequent flight to the alternate airport.
Final reserve Not used yet.
Additional fuel Let's assume you did not take any.


Under these assumptions you would be using the Final reserve fuel for your go around at the alternate airport. At this point you should declare an emergency (see Do I have to declare an emergency if I cut into fuel reserves?) by broadcasting


  MAYDAY, MAYDAY, MAYDAY, FUEL


as explained in What is the correct phraseology for declaring a fuel emergency?. ATC will then assist you to get to any suitable airport as soon as possible.