This video was posted to reddit recently. A new structure is being planned to totally encompass the existing Chernobyl power plant site. The new arch will allow dismantling the existing sarcophagus containment building. The sarcophagus was built as quickly as possible, and was expected to last for a 20 year lifetime. The 25th anniversary of the accident is next Tuesday.
The Chernobyl and Fukishima nuclear accidents show that all of the costs must be included when deciding if nuclear power is worth the risk. The analysis must account for possible long term losses created by new "exclusion zones" necessitated by future nuclear accidents. Somehow, I don't think that has been properly factored into the current cost/benefit analysis. We only have one earth.
p.s. This Chernobyl documentary is worth watching.