The robot "Packbot" went to the opening to the "train room" and the survey meter went overscale. The actual radiation level at the opening could be a lot higher, and I hate to think how high it is INSIDE the room. The radiation could have fried the bot.
Notice how rapidly the radiation level rose, from 18 to 300 to 2000 to over 5000, as the robot went inside the air conditioning room to the entrance of the "train room"
TEPCO's press handout on August 3 (in Japanese; English version is not yet out):
TEPCO also has the video of the operation, here (it's a zip file).