[quote]

The radiation level of the surface of the contaminated water is 1.8 mSv per hour, but gamma rays, beta radiation were registered as high as 110 mSv. The leakage may have contained about 100,000 becquerels per cubic centimeter of radioactive strontium out the Beta, this concentration is equivalent to a million times that of seawater concentration standards.

[/quote]

Source: Yomiuri

December 04, 2011

<Draining Water on Underground Floor of Turbine Building (T/B)>

◇Status of highly concentrated accumulated radioactive water treatment facility and storage tank facility [Treatment Facility]

・6/17 20:00 Full operation of radioactive material removal instruments started.

・6/24 12:00 Start of desalination facilities operation

・6/27 16:20 Circulating injection cooling started.

・8/7 16:11 Evaporative Concentration Facility has started full operation.

･8/19 19:33 We activated 2nd cesium adsorption facility (System B) and started the treatment of accumulated water by the parallel operation of cesium adsorption instrument and decontamination instrument. At 19:41, the flow rate achieved steady state.

12/2 18:00 After completing the reinforcement work to on-site power, we stopped the evaporative concentration apparatus in order to start receiving power from the power source*.

* 2nd cesium absorption facility continued operation and treated accumulated water. Reactor water injection was continued by desalinated water in the buffer tank. There was no impact

from this power source switch over.

12/3 8:04 We stopped the water desalination apparatus (reverse osmosis membrane type). 8:30 We stopped the cesium adsorption apparatus.

13:30 We restarted the water desalination apparatus (reverse osmosis membrane type) after power receiving operation.

14:22 We restarted the cesium adsorption apparatus

14:34 We restarted the evaporative condensation apparatus.

12/4 11:33 Workers found that there was puddle water inside the barrier around the evaporative condensation apparatus (the estimated volume of water was approx.45 m3). At 11:52, stopped the apparatus.

12:14 Workers made visual inspection of the apparatus and thought that the leakage stopped. After that, conducted investigation. At 14:30, we found crack in the barrier made of

concrete and water was leaking to the gutter (surface dose rate of leaked water: beta ray 110mSv/h, gamma ray 1.8mSv/h). We are considering emergency response to stop leakage of

water to the outside of the barrier. In the meantime, water desalination apparatus is continuing operation. As we have sufficient volume of desalinated water, there is no impact on the Reactor water injection.

[Storage Facility]

・6/8～ Big tanks to store and keep treated or contaminated water have been transferred and installed sequentially.◇Accumulated water in vertical shafts of trenches and at basement level of building

From 17:48 on December 3 – MP-8’s dosage rate data was lost. As we could not figure out the cause and could not resume, we used an alternative dose rate meter located around MP-7 and MP-8 (enhancement to monitoring that

coincides with nitrogen injection to RPV). The most recent data did not have change from that of the day before. We are planning to repair MP-8.

19:07-21:01 on December 3 In order to transfer and cut the power cable* for the auxiliary transformer power board that receives power from Okuma Line 2L, we changed the power source for that power board. With this work, lighting at rest places, local air extractor and continuous dust monitoring at the main gate, anti-earthquake main building and rest places at the service building for Units 5 & 6 stopped. After completion of the power source switchover, stopped equipments resumed operation.

* This is a preparation work to stop leakage of water from the duct, STr, Unit 3 to the control building found on August 4 (announced on August 8).



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