IAEA Briefing on Fukushima Nuclear Accident (10 April 2011, 15:00 UTC)
Presentation Summary of Reactor Status
On Sunday, 10 April 2011, the IAEA provided the following information on the current status of nuclear safety in Japan:
1. Current Situation
Earthquake of 7th April
External power has been restored at all sites affected by the 7th April earthquake. The 3 litres of water that were spilled at Onagawa NPP have been cleaned up.
Changes to Fukushima Daiichi Plant Status
Overall, the situation at the Fukushima Daiichi plant remains very serious but there are early signs of recovery in some functions such as electrical power and instrumentation.
In Units 1, 2 and 3, 60,000 tons of contaminated water need to be removed from the turbine buildings and trenches. This water will be transferred to the condensers of each unit and the Radioactive Waste Treatment facility. In addition, temporary storage tanks have been ordered to provide additional capacity for the water and will be located adjacent to the Radioactive Waste Treatment facility. In Unit 2 water transfer from the condenser to the condensate storage tank was completed on 9th April.
…On 9th April, deposition of both iodine-131 and cesium-137 was detected in 5 and 6 prefectures respectively. The values reported for iodine-131 ranged from 7.8 to 650 becquerel per square metre and for cesium-137 from 3.3 to 370 becquerel per square metre. The highest deposition was reported for both, iodine-131 and cesium-137, in the prefecture of Ibaraki.
Gamma dose rates are measured daily in all 47 prefectures, the values tend to decrease. Dose rates are also reported daily for the Eastern part of the Fukushima prefecture, these values are decreasing as well. As of 9th April, the gamma dose rates, reported for distances of more than 30 km to Fukushima-Daiichi, ranged from 0.2 to 26 μSv/h.
In an additional monitoring programme, set up by MEXT in cooperation with local universities, measurements are made in 27 cities in 14 prefectures. As of 9th April, in 19 cities, the gamma dose rates were below 0.1 μSv/h. In 7 cities, gamma dose rates range from 0.13 to 0.21 μSv/h. In Fukushima City, a value of 0.46 μSv/h was observed. Typical normal background levels are in the range of 0.05 to 0.10 μSv/hr.
As of 7th April, iodine-131 and cesium-137 was detectable in drinking water in a few prefectures at levels far below those that would trigger recommendations for restrictions of drinking water. As of 7th April, one restriction for infants related to I-131 (100 Bq/l) is in place as a precautionary measure in only one village of the Fukushima prefecture.