What's Burma building in there?

This Google Earth image of a mysterious building in Northern Burma posted by the New America Foundation's Jeffrey Lewis on the Arms Control Wonk blog has been making the Internet rounds.

It may look like an Olympic-sized swimming pool, but the thing is huge -- 80 meters long on each side and seems to roughly match up with the Sydney Morning Herald's report of a Burmese nuclear reaction construction project. The Institute for Science and International Security has more.

No one seems to have a conclusive idea about what the thing is yet, but it does seem worth keeping an eye on. Via James Fallows, the Lowy Interpreter has a useful roundup of the latest Burma nuke speculation.