Fukushima Nuclear Accident Update Log (Updates of 30 March 2011)

From IAEA :

" IAEA Briefing on Fukushima Nuclear Accident (30 March 2011, 16.30 UTC)

On Wednesday, 30 March 2011, the IAEA provided the following information on the current status of nuclear safety in Japan.

1. Current Situation

Overall at the Fukushima Daiichi plant, the situation remains very serious.

With respect to the water that is present in the turbine buildings. In Unit 1, water has continued to be pumped into the condenser with 3 pumps (6.5 ton/hour each) and the water level has reduced from 40cm to 20cm. In Unit 2 from 07.45 UTC, pumping of water from the Condensate Storage Tank into the Surge Tank was started so that the that condenser can be drained to the Condensate Storage Tank and contaminated water can be pumped out from the Turbine building into the condenser. The same process of pumping the water from the Condensed Water Storage Tank into the Surge Tank was started on Unit 3 at 08.40 UTCon March 28.

Near the Unit 3 building, 3 workers spilled water over themselves when removing a flange from seawater pipes on the residual heat removal system (RHR). After showering, contamination was not detected.

Fresh water has been continuously injected into the Reactor Pressure Vessel (RPV) through feed-water line at an indicated flow rate of 8.0 m3/h at Unit 1. The pumping of freshwater into the RPV has been switched from fire trucks to temporary electrical pumps with diesel generator. At Units 2 and 3 fresh water is being injected continuously through the fire extinguisher line at an indicated rate of 7 m3/h using a temporary electric pump.

The indicated temperature at the feed water nozzle of the RPV of Unit 1 has decreased from 323 oC to 281 oC and at the bottom of RPV remained stable at 134 oC. There is a corresponding decrease in Drywell pressure. At Unit 2 the indicated temperature at the feed water nozzle of the RPV has increased from 154 oC to 177 oC and at the bottom of RPV has increased from 78 oC to 88 oC. Indicated Drywell pressure remains at atmospheric pressure. For Unit 3 the indicated temperature at the feed water nozzle of the RPV is about 75 oC and at the bottom of RPV is about 116 oC. The validity of the RPV temperature measurement at the feed water nozzle is still under investigation."