The True Battle of Chernobyl - Uncensored:
I suggest that you watch this magnificent documentary when you have enough time(takes one an a half hours). Everyone knows chernobyl, atleast they should! It was the worst nuclear disaster in the history. This documentary gives a great window view to the whole event, it shows you how it happened and how the world reacted to it. It also shows what horrible tasks the liquidators had to do. This documentary is a must see.
Inside Chernobyl's Sarcophagus:
A group of soviet scientists in 1991 go inside the sarcophagus to look for the missing nuclear fuel. It basically is a suicide mission. A great documentary also.
Additional links:
Chernobyl Disaster on Wiki
Pripyat on Wiki