TEPCO briefing to IAEA

Here is a section of the plant-specific data that TEPCO has given today to the International Atomic Energy Agency. Particularly interesting are the specific volumetric flowrates of core cooling water being provided, as are the now-diverging pressure vessel pressure readings on No. 2 plant. Some conditions noted as "not reported" in some of these briefings are actually failed indications; No. 3 plant feed nozzle temperature is still all over the place and likely failed.

Current Situation

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

On 3rd April, transferring of water from the Unit 1 condenser to the condenser storage tank was started in preparation for transferring water in the basement of the Unit 1 turbine building to the condenser. On 2nd April, transferring of water from the Unit 2 condenser to the condenser storage tank was started in preparation for transferring water in the basement of the Unit 1 turbine building to the condenser.

TEPCO has identified a possible leakage path from the Turbine building of Unit 2 to the sea via a series of trenches/tunnels used to provide power to the sea water intake pumps and supply of service water to the reactor and turbine buildings. On 4th April, a tracer was used in an attempt to determine where the water was coming from. So far, the tracer has not been observed in the water leaking into the sea.

In Unit 1 fresh water has been continuously injected into the reactor pressure vessel through feed-water line at an indicated flow rate of 6 m3/h using a temporary electric pump with off-site power. In Units 2 and 3 fresh water is being injected continuously into the RPVs through fire extinguisher line at indicated rates of 9 m3/h and 7 m3/h using a temporary electric pump with off-site power.

In Unit 1 the indicated temperature at the feed water nozzle of the RPV decreased from 243 °C to 234 °C and at the bottom of RPV stable at 115°C. The RPV pressure indications are fluctuating and Drywell pressure is stable. The RPV pressure indications for the 2 channels are diverging. For Unit 2 the indicated temperature at the feed water nozzle of the RPV is stable at 142°C. The temperature at the bottom of RPV was not reported. Indicated Drywell pressure remains at atmospheric pressure. In Unit 3 the indicated temperature at the feed water nozzle of the RPV is stable at 114°C and at the bottom of RPV is about 85°C. The validity of the RPV temperature measurement at the feed water nozzle is still under investigation.

In Unit 2 additional water was injected via the Spent Fuel Cooling System line to the spent fuel pool by a temporary pump on April 4. In Unit 4, 180 T of fresh water was sprayed to the spent fuel pool by concrete pump on April 3rd.

There has been no change of status on Units 5-6 and the Common Spent Fuel Storage Facility.

This is the end of the TEPCO section that I'm reprinting; the rest is about site monitoring and radioactive effluent / discharge and we've had quite a lot of solid data on that just this morning. At the moment, none of the specific data given above seems alarming given the other data we've reviewed and the trend analysis.

10:45 AM Eastern Tuesday 4/5
ATOMIC POWER REVIEW