corporate intranet portal with drupal 7 I am new to drupal. I need to develop a corporate intranet portal using drupal 7.
I have features like,

Employee profile creation

Announcement (Internal announcement, internal opportunities, display
new joiners with their      photo and info)

Employee birthday celebration

Awards

Discussion board

Survey

LMS

Event calendar
and many more.


I would like to know whether corporate portal can be built with drupal.
Please let me know if there any modules for the above requirement or any opensource for this .
Thanks.
I would like to know whether corporate portal can be built with
  drupal.


Yes it is possible.


  Please let me know if there any modules for the above requirement or
  any opensource for this.


The question cannot be answered properly without knowing the exact requirements and then digging very deep. The result would be mostly writing a book. 

To be honest as you are new to drupal and the way your question "sounds" to me" you are likely to fail with the project. Therefore I would recommend you check out how far open atrium (Drupal 6) or other install profiles / distributions meet your requirements and try to sell one of these (plus customization) to your client. Or at least first look how the authors of open atrium, Drupal Commons and others do things and then ask specific questions.