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Old 04-08-2011, 08:13 AM
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The Dominican
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An update published by the World Health Organization on April 4th.
http://www.wpro.who.int/NR/rdonlyres...0/Sitrep24.pdf





IAEA Briefing on Fukushima Nuclear Accident (7 April 2011, 18:00 UTC)
Presentation:
Summary of Reactor Status
Radiological Monitoring and Consequences
Status of Fukushima Units
Marine Environment Monitoring

1. Current Situation
Overall, the situation at the Fukushima Daiichi plant remains very serious although there are early signs of recovery in some functions such as electrical power and instrumentation.
On 6th April it was reported that the leakage of water from the sidewall of the pit closest to the sea has stopped after coagulation agents (liquid glass) were injected into the holes drilled around the pits. Work continues to prevent further releases to the sea.
According to the TEPCO Press Release of 4th April, approximately 10,000 T of water from the radioactive waste treatment plant and 1,500 T of subsurface waters stored in the sub drain pits of Unit 5 and 6 are being discharged to the sea to provide room to store water with higher levels of radioactivity in a safer manner. TEPCO has estimated that these discharges would increase the effective dose to a member of the public by 0.6 mSv, if he/she were to eat seaweed and seafood from 1 km from the discharge point every day for a year. It should be noted however that the movements of all ships, including fishing boats, are restricted within a 30km zone from the NPP.
In Unit 1 fresh water is being continuously injected into the reactor pressure vessel through the feed-water line at an indicated flow rate of 6 m3/h using a temporary electric pump with off-site power. Fresh water is being injected continuously into the RPVs through the fire extinguisher lines in Units 2 and 3 at indicated rates of 8 m3/h and 7 m3/h respectively using a temporary electric pump with off-site power.
As of 6th April, TEPCO started injecting nitrogen gas to Unit 1 containment vessel to provide an inerted atmosphere to reduce the possibility of hydrogen combustion within the containment vessel.
On Unit 1 the indicated temperature at the feed water nozzle of the RPV is 224° and at the bottom of RPV it is 117°. Instrumentation ‘B’ for Reactor Pressure indicates that the pressure in the RPV is increasing and instrumentation ‘A’ indicates that it has stabilized. NISA has indicated that some instruments in the reactor vessel may not be working properly. Drywell pressure has increased slightly due to the injection of nitrogen. In Unit 2 the indicated temperature at the feed water nozzle of the RPV is stable at 143°. The temperature at the bottom of RPV was not reported. Indicated Drywell pressure remains at atmospheric pressure. The indicated temperature at the feed water nozzle of the RPV in Unit 3 is 88° and at the bottom of RPV is about 115°.
Additional water was injected via the Spent Fuel Cooling System line to the spent fuel pool by a temporary pump on 4th April.
There has been no change in status on Units 4, 5, 6 and the Common Spent Fuel Storage Facility
2. Radiation monitoring
On 6th April, low levels of deposition of both I-131 and Cs-137 were detected in 4 and 6 prefectures respectively. The values reported for I-131 ranged from 3.4 to 10 becquerels per square metre, for Cs-137 from 4.9 to 19 becquerels per square metre. Gamma dose rates continue decreasing . There is no significant change in gamma dose rates reported for 6th April compared to yesterday.
As of 5th April, I-131 and Cs-134/137 was detectable in drinking water in a small number of prefectures. All values were well below levels that would initiate recommendations for restrictions of drinking water. As of 6th 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.
TEPCO is responsible for near-shore sampling, taking samples of surface seawater. Samples near discharge areas are collected daily. Until 3rd April a general decreasing trend was observed. However, after the discharge of contaminated water at 4th April, an increase from about 11 kBq/l as measured at 09:00 to 41 kBq/l at 14:00 for I-131; from 5.1 kBq/l at 09:00 to 19 kBq/l for both, Cs-134 and Cs-137 at 14:00 was recorded. On the 5th April a decrease was observed as compared to the previous day, with seawater concentration of 5 kBq/l for Cs-137 and 11 kBq/l for I-131.
Since 4th April TEPCO added 3 new sampling points 15 km offshore, in addition to the already established 3 sampling points at the same distance, this resulting in a total of 6 sampling points situated along a north-south transect at a distance of 15 km from the coast.
Levels of radionuclides reported at these l°ations for the 5th of April are in the range 57 - 200 Bq/l for I-131, 18 - 310 Bq/l for Cs-134 and 18 - 320 Bq/l for Cs-137.
There were no new data for 30 km off shore monitoring, carried out under the responsibility of MEXT, compared to yesterday’s briefing.
On 6th April the marine expert from the IAEA Environment Laboratories Monaco completed his mission in Japan. From the 2nd to 4th April he embarked on the research vessel MIRAI to observe the sampling conducted 30 km offshore. He visited the JAEA laboratory in Tokai where the gamma spectrometric analyses are performed. He briefed representatives of the Japanese Government
Since our written briefing of yesterday, data related to food contamination were reported on 6th April by the Japanese Ministry of Health, Labour and Welfare. These reported analytical results covered a total of 78 samples taken on 3rd April (2 samples), 4th April (39 samples), 5th April (35 samples) and 6th April (2 samples). Analytical results for 52 of the 78 samples for various vegetables, spinach and other leafy vegetables, fruit (strawberry) and unprocessed raw milk in eight prefectures (Fukushima, Gunma, Hyogo, Ibaraki, Kanagawa, Niigata, Saitama and Yamagata) indicated that I-131, Cs-134 and/or Cs-137 were either not detected or were below the regulation values set by the Japanese authorities. However, it was reported that analytical results for 26 of the total 41 samples taken in Fukushima prefecture for various vegetables, spinach and other leafy vegetables indicated that I-131 and/or Cs-134/Cs-137 exceeded the regulation values set by the Japanese authorities.
On 5th April, the Japanese Ministry of Health, Labour and Welfare issued a press release indicating that a new provisional regulation value was set for I-131 at a limit of 2000 Bq/kg in fishery products.
As of 4th April, food restrictions (distribution and/or consumption) are in place in four prefectures (Fukushima, Ibaraki, T°higi, and Gunma) and in certain l°ations in Chiba prefecture (Katori City, Tako Town and Asahi City).
In Fukushima, there are restrictions on the consumption of leafy vegetables, headed and non-headed leafy vegetables (e.g. spinach, komatsuna, cabbage), and flower-headed brassicas (broccoli, cauliflower). There are also restrictions on the distribution of headed and non-headed leafy vegetables, flower-headed brassicas (including turnips), spinach, kakina and unprocessed raw milk produced in the prefecture.
In Ibaraki, there are restrictions on the distribution of unprocessed raw milk, parsley, spinach and kakina produced in the prefecture.
In Chiba, there are restrictions on the distribution of spinach produced in Katori City and Tako Town. There are also restrictions on the distribution of spinach, chingensai, shungiku, sanchu, celery and parsley produced in Asahi City.
In Gunma and Tohigi, there are restrictions on the distribution of spinach and kakina produced in these prefectures.
3. IAEA Activities
The two agency experts in BWR technology are in Japan to have a direct exchange of views with the Japanese counterparts. They met with officials of NISA, TEPCO, the Japanese Atomic Energy Commission and the Nuclear Safety Commission. They visited the off-site emergency response center and the Fukushima Daiichi site. A third agency expert will join the team in Tokyo to have follow-up meetings with TEPCO and NISA at the end of the week.
The following countries have submitted monitoring data and/or links to national websites where data is available: Austria, Belgium, Bulgaria, Canada, China, Finland, France, Greece, Iran, Ireland, Italy, Malaysia, Poland, Romania, Russian Federation, Singapore, Spain, Sweden, Switzerland, and Ukraine.
(Reuters) - A major aftershock rocked northeast Japan on Thursday and a tsunami warning was issued for the coast devastated by last month's massive quake and tsunami that crippled a nuclear power plant.
The warning was later lifted and no tsunami was reported after the quake, which struck shortly before midnight. No damage from the tremor, measured at magnitude 7.4 by the Japan Meteorological Agency, was detected at the Fukushima Daiichi nuclear plant, operator Tokyo Electric Power Co (TEPCO) said.
Workers struggling to bring the plant under control were evacuated but returned once the tsunami warning was lifted, a TEPCO official said.
There were signs progress had been made toward stabilizing the plant, though overall the situation was still very serious, an official at U.N. nuclear watchdog the International Atomic Energy Agency (IAEA) said late on Thursday, before the aftershock struck.
Large parts of northern Japan, whose infrastructure was severely damaged by the March 11 quake and tsunami, were without electricity following the latest of many aftershocks, the biggest since last month's killer quake.
Toru Hanai, a Reuters photographer in Oshu, Iwate prefecture, near the epicenter of Thursday's aftershock, said his hotel lost power and a water pipe burst.
"Everything fell. My room is a complete mess and power is widely out in this area," he said.
In the capital, Tokyo, buildings also shook.
"It started out as nothing much, then the building started swaying quite strongly," a Reuters witness said.
By 1:30 a.m. (12:30 p.m. EDT) seven people were reported injured, two seriously, a spokesman for the National Police Agency said.
Last month's 9.0 magnitude quake triggered tsunami waves which swept in along the coast, wiping out towns. About 28,000 people were killed or are missing.
The disaster disrupted industry and affected supply chains around the world but it was not immediately clear if Thursday's aftershock would compound those problems.
At the Fukushima nuclear plant, TEPCO said it was continuing to inject nitrogen into reactor No.1 in order to prevent the risk of a hydrogen gas explosion.
An IAEA official said radiation in the region around the plant, as measured by gamma dose rates, had peaked in the early days of the crisis, and aside from a rise on March 22, had since fallen to "a level very close to background."
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