There is currently great amount of radioactive waste water in the turbine
buildings of the Fukushima Daiichi Nuclear Power Station and especially
the turbine building of Unit 2 has extremely high level radioactive waste
We think it is necessary to transfer the radioactive waste water to the
Central Radioactive Waste Disposal Facility in order to store it in a
stable condition. However, ten thousand of low level radioactive waste
water has been already stored and we have to discharge the existing low
level radioactive waste water to receive new liquids.
In addition, as low radioactive subsurface water is piling up in sub-drain
pits of Unit 5 and 6 and a part of subsurface water is running into
buildings, we are concerned that important equipment to secure the safety
of reactors will be submerged.
Based on the Section 1 of the Article 64 of the Nuclear Reactor Regulation
Law, we have decided to discharge to the sea approximately ten thousand
tons of the accumulated low level radioactive water and a total of 1,500
tons of the low level radioactive subsurface water stored in the sub drain
pits of Unit 5 and 6 as soon as we get ready.
We evaluate approximately 0.6 mSv of effective radioactive doses per year
for adults as the impact on the discharge of the low radioactive waste
water to the sea if they eat adjacent fish and seaweeds every day. The
amount (0.6 mSv of effective radioactive doses per year) is one-forth of
annual radioactive dose to which the general public is exposed in nature.