Press Conference by the Chief Cabinet Secretary
CHIEF CABINET SECRETARY EDANO As I announced this morning, I will now give a report on the situation in the Unit 3 reactor at the Fukushima Dai-Ichi No. 1 nuclear power plant.
This morning, I reported that water supply functions had been lost in the Unit 3 reactor of the Tokyo Electric Power Fukushima Dai-Ichi No. 1 nuclear power plant. As a result of this, water levels dropped inside the pressure vessel, where the fuel rods are immersed, and it is believed that the top of the fuel rods was exposed above the surface of the water. Because of this, at 9:05am a safety valve on the innermost reactor vessel inside the nuclear reactor was opened, lowering the pressure inside the reactor. At 9:08am, injection began not of sea water but pure water, and at 9:25 the step was taken of mixing boric acid with the water in order to increase safety further. Following this, venting began in the containment vessel at 9:20, and as a result it is believed that cooling is now underway in the containment vessel in the reactor. Since venting began at 9:20, and continuing from yesterday, a small amount of radioactive material is thought to have been released from the exhaust duct.
Monitoring of radiation levels on the spot is ongoing. At point MP4, where a reading of 1,015μSv was detected yesterday, a radiation level of 44.6μSv was recorded at 00:30 this morning, and a level of 36.7μSv at 6:00am. After the start of venting around 9:20, a reading of 76.9μSv was recorded at 9:20 and of 70.3μSv at 9:30.
We are continuing to monitor the situation on an ongoing basis. At present the situation is that as a result of the venting, gas is being released that includes small, controlled amounts of radioactive material within the expected levels. These steps are being carried out in accordance with the procedures for dealing with a situation of this kind. Please be assured that the level of radiation being released is not sufficient to have any effect on human health.
However, I understand that concern is high about the risk of exposure among evacuees. We are considering taking the following measures, while confirming the desires of Fukushima Prefecture.
We are compiling a list of all evacuees in Fukushima Prefecture. As a matter of national responsibility, the government is liaising with Fukushima Prefecture in establishing first aid stations staffed by specialists in each emergency evacuation area. Multiple specialist teams will be assigned to monitor all evacuees and other concerned persons for radiation exposure, as well as providing follow-up evaluations and liaisons with medical response services where necessary. I will be asking all the prefectures concerned for their cooperation in this matter; we are currently in the process of making arrangements along those lines.
This ends my report on the latest situation at the nuclear power plant.
That is all from me for now.
Please wait a moment.
I have some additional information to give you.
Regarding data from the MP4 monitoring point I mentioned earlier: At 8:33 a reading of 1,204.2μSv was recorded. This was not the direct effect of the venting. If you look at the overall picture presented by these figures, you will see that although there are large fluctuations in radiation levels, there have been no sudden rises as a result of the venting.