H27.5月末 H27.3.12現在
66%
59%
27%
3% 31%
14%
[Reference]
March 16, 2015 Tokyo Electric Power Company
Regarding contaminated water purification
Treatment of contaminated water stored in tanks
○The effective dosage at the site boundary attributed to tanks (evaluated value) should hit the target of less than 1mSv/year by the end of the current fiscal year. (80% of the RO concentrated salt water will have been treated as of the end of March.)
○The treatment of RO contaminated salt water, with the exception of 3 percent of the total (approximately, 20, 000 tons) which includes rich sea water foulants produced at an early phase of the accident, will be completed by the end of May.
Continued treatment of groundwater accumulating in the reactor buildings
○Groundwater and other water (Approx. 300 tons/day of groundwater + 100 ton/day of water pumped up from well points) accumulating in the reactor buildings will be put through the cesium adsorption device and the second cesium adsorption device (Kurion and Sarry) in order to remove Strontium, and then further decontaminated through ALPS.
○There will be continuous effort to decrease the amount of groundwater running into the reactor buildings with new measures being explored, as well as efforts to reduce the accumulation of water in the buildings and decontaminate water which has already entered the building.
Further decontamination of Strontium‐removed water
○In order to further lower risk, the water which has had strontium removed through the use of non‐ALPS facilities will be re‐treated through the ALPS facility.
○Water which was treated through ALPS during the period in the past when the facility was not performing optimally will also be re‐treated through the ALPS facility.
○As part of the final review of the water discharge, further decontamination of treated water other than the above will be considered.
・
・
0 1 2 3 4 5 6 7 8 9 10
2013/9/24 2013/10/24 2013/11/24 2013/12/24 2014/1/24 2014/2/24 2014/3/24 2014/4/24 2014/5/24 2014/6/24 2014/7/24 2014/8/24 2014/9/24 2014/10/24 2014/11/24 2014/12/24 2015/1/24 2015/2/24 2015/3/24
ミリシーベルト/年
When not purified by ALPS
Lower to this level by ALPS
1mSV/year
FY2014 FY2013
Transition of the effective dosage at the site boundary attributed to tanks
Condition of contaminated water purification
RO concentrated salt water
Strontium treated water
ｏContaminated water with rich foulants of seawater produced at an early phase of the accident.
・A lot of time is required for purifying contaminated water which includes rich foulants of seawater as calcium and magnesium hinder the rated flow operation to work normally.
・It requires another few months to treat the water.
Treated water via ALPS Treated water
3/31
Residual water at the bottom of tanks
○Due to the structure of the facility, residual water will be produced as contaminated water retained at the bottom of a tank is hard to be pumped up completely with an installed pump.
○The total volume of residual water is estimated to be approximately 20,000 tons.
○Keeping in mind safety first, the residual water will be removed when dismantling each tank following the preventive measures for dust scattering/ radiation exposure.
・
Contaminated water with rich foulants of seawater
Residual water Estimated to be 20,000 tons.
As of Mar. 12, 2015
End of May, 2015
mSV/year
