It looks like the survey meter on the robot (no info on whether it was Packbot or Quince) also went overscale.
From Jiji Tsushin (10:47PM JST 8/2/2011):
TEPCO announced on August 2 that the radiation level in the air conditioning room on the 2nd floor of the reactor building of Reactor 1 was over 5 sieverts/hr (or 5,000 millisieverts/hr). It is the highest indoor radiation ever recorded at the plant, higher than 4 sieverts/hr recorded also in the Reactor 1 reactor building on June 3. TEPCO closed off the room.
同室には原子炉格納容器の圧力を逃がす「ベント」の配管と、非常用ガス処理系配管との合流点があり、１日 に屋外で最高の毎時１０シーベルト（１万ミリシーベルト）以上が測定された主排気筒との接続部分の上流に当たる。主排気筒と同様に、東日本大震災翌日のベ ントの際に放出された高濃度の放射性物質が付着したと考えられるという。
The vent duct that releases pressure inside the Containment vessel and the emergency gas processing pipe meet inside the room, which is upstream from the main exhaust stack where over 10 sieverts/hr radiation was measured on August 1. According to TEPCO, it is possible that the high concentration of radioactive materials got stuck inside the pipes when the venting was done on the next day after the March 11 earthquake.
According to Yomiuri, 10 sieverts/hr radiation would be emitted from 2 grams of radioactive cesium.
According to Kyodo News Japanese, the room is called the "train room" by TEPCO.
I sure hope the room is located nowhere near where workers have to pass by, on their way to the upper floors to install the heat exchanger for the Spent Fuel Pool.
(If there is any fuel left in the pool to cool, that is.)