Japanese Earthquake, Tsunami, and Nuclear Reactors

UPDATE AS OF 9:30 A.M. EDT, MARCH 25:
Japanese officials are investigating the source of higher radiation readings at reactor 3 at the Fukushima Daiichi nuclear power plant after two workers were contaminated while laying cable in the turbine building. Tests of the water in which the workers were standing contained a concentration of radioactive material many times the level normally found in water circulating in the reactor, the Nuclear and Industrial Safety Agency said.

"When we looked into the composition of the water, the source...seems to be the reactor core," said NISA's Hidehiko Nishiyama. "Another possibility is the spent fuel, and we cannot rule out that possibility either."

Several possibilities could account for the presence of radioactive materials in the turbine building. Seawater sprayed onto the fuel pool area may have washed over the floor of the fuel pool area onto the turbine building and leaked through the damaged roof into the basement of that building. Other possibilities include a problem with an interconnected system to the primary containment, such as the main steam system, or a small opening in the reactor containment structure.

Japanese authorities recommended residents within 30 kilometers of the plant evacuate voluntarily, extending the recommendation from 20 kilometers. Damage to infrastructure in the area from the earthquake severely limits the ability to provide water, food and other necessary supplies to people sheltering in their homes for the coming weeks.

ETA With all ther concern about the nuclear plants, it is easy to forget that the entire area around Daiichi was devastated by a 45 foot tsunami and a Richter Level 9 earthquake.

Tokyo Electric Power Co. is stepping up efforts to switch from sea water to fresh water for cooling the reactors and used fuel storage pools. The United States government has urged the switch to fresh water as soon as possible and is providing two U.S. Navy barges, each of which can carry up to 1,000 tons of water. The ships are scheduled to reach port about 60 kilometers from the Daiichi plant in about three days. Japanese workers at the site will install pipes and hoses to carry the water to the plant.

[ETA The Navy guy's facebook was correct.]

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Press Release (Mar 25,2011)
Special Measures for the electricity bills for the customers who have suffered from the Tohoku-Chihou-Taiheiyo-Oki Earthquake (2011)


We sincerely express our best wish for all the customers who have suffered from the Tohoku-Chihou-Taiheiyo-Oki Earthquake ("Earthquake").

If requested from customers who suffered from the Earthquake in the areas where the Disaster Relief Act was applied, we will offer special measures for the electricity bills for such customers (previously announce on March 15th, 16th and 18th).

Further to the additional application of Disaster Relief Act to 4 municipalities in Chiba Prefectures, we have decided to expand areas to those we apply exceptional conditions of electricity supply (Special Measures for the customers who have seriously suffered from Tohoku-Chihou-Taiheiyo-Oki Earthquake) to General Supply Provisions, based on a proviso of Section I of Article 21 of Electricity Business Act., have applied to Ministry of Economy, Trade and Industry for and have acquired an additional approval. The contents are as follows.

‹Eligible Customers>
All the customers who have suffered from the Earthquake since March 11th in the areas shown below to which the Disaster Relief Act is applied in relation to the Earthquake and who applied for the special measures:

Ibaraki Prefecture; Mito city, Hitachi city, Tsuchiura city, Ishioka city, Ryugasaki city, Shimotsuma city, Joso city, Hitachiota city, Takahagi city, Kitaibaraki city, Kasama city, Toride city, Ushiku city, Tsukuba city, Hitachinaka city, Kashima city, Itako city, Hitachiomiya city, Kasumigaura city, Sakuragawa city, Kamisu city, Namegata city, Hokota city, Tsukubamirai city, Omitama city, Ibaraki town, Oarai town, Shirosato town, Tokai village, Daigo town, Ami town, Naka city, Miho village, Kawachi village, Chikusei city, Inashiki city, Tone town Tochigi Prefecture; Utsunomiya city, Oyama city, Moka city, Otawara city,Yaita city, Nasukarasuyama city, Sakura city, Nasushiobara city, Mashiko town, Motegi town, Ichikai town, Haga town, Takanezawa town, Nasu town, Nakagawa townChiba Prefecture; Asahi city, Katori city, Yamatake city, Tsukumo town, Chiba city (Mihama ward), Narashino city, Abiko city and Urayasu city, and other neighboring areas below. Ibaraki Prefecture; Bando city, Moriya city, Yachiyo town, Yuuki city, Koga city Tochigi Prefecture; Nikko city, Kanuma city, Shimotsuke city, Shioya town, Mibu town, Kaminokawa town, Tochigi city, Nogi town Chiba Prefecture; Noda city, Kashiwa city, Choshi city, Tohnosyo town, Narita city, Yachimata city, Togane city, Tomisato city, Sosa city, Sakae town, Oamishirasato town, Shibayama town, Yokoshibahikari town, Kanzaki town, Tako town, Inzai city, Chiba city (Chuo ward, Hanamigawa ward, Inage ward), Ichikawa city, Funabashi city, Yachiyo city Tokyo; Edogawa ward

‹Special Measures>
1.Deferring the due date for 1 month As to the electricity bill for February 2011 (whose due date is March 11 or afterward), March 2011, and April 2011, the due date* is deferred for 1 month.
*The due date is 30 days after the next day of meter-reading.

2.Exemption from payment for the months of no electricity use If you have been used no electricity since the occurrence of damage from the Earthquake, we do not charge any amount for the 6 month after the month when the damage of the Earthquake has risen.

3.Exemption from the payment for the construction If you have been used no electricity, terminate the contract of electricity since the occurrence of damage from the Earthquake, and applied for a new electricity contract by the end of September, 2011, basically we do not charge any amount for the construction.

4.Exemption from the payment for temporary construction If you applied for an contract of temporary electricity for the purpose of restore the damaged areas by the end of September, 2011, we do not charge any amount for the temporarily construction.

5.Exemption from payment of the basic fee for the broken facilities due to the Earthquake If customers' electricity facilities partly broke down due to the Earthquake, we do not charge basic fees for the broken facilities unless the facilities become in service, by the end of September 2011.
6.Exemption from the construction to install electricity meters etcetera If you apply for changing the position of an electricity meter or a service wire by the end of September 2011, basically we do not charge any amount for the first part of the construction.

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Status of Fukushima Daiichi nuclear power station as of 21:00, March 25,
2011
Here is information regarding the status of Fukushima Daiichi nuclear power station from the news reports aired by NHK in this afternoon and evening on March 25.

 Nuclear and Industrial Safety Agency pointed a possibility that radioactive material from damaged fuel rods would have leaked into the environment based on the fact that water containing high amount of radioactive material was found at unit-3 on March 24. (19:18, March 25)

 The self defense force released video image of the nuclear power station taken from a helicopter. Steam rising from the spent fuel pool of the unit-3 was observed. (18:21, March 25)

 Nuclear and Industrial Safety Agency ordered TEPCO take preventive step after the accident in which three workers were exposed to radiation at unit-3 on March 24. (18:50, March 25)

 It has been pointed out that the reactor will become eroded if seawater is injected continually. The self defense force and U.S forces made decision to consolidate a system to feed freshwater from a large ship of U.S forces.
(16:30, March 25)

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<March 25th>
06:45-10:20 Water injection to Spent Fuel Pool (SFP) via reactor water clean up system started in Unit 4
10:30-12:19 Water injection to SFP via reactor water clean up system started in Unit 2
11:00 Switching the water source for injecting into Reactor Pressure Vessel from seawater to freshwater was started at Unit 2 and 3. That has become ready at Unit 1.
2.

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Lowe's Ups Defective Drywall Settlement Offer
Facing withering criticism, Lowe’s Companies Inc. has increased its offer to settle toxic drywall lawsuits. According to ProPublica, the home improvement store chain is offering as much as $100,000 to customers who claim their homes and health sustained damages because of toxic drywall they allegedly purchased at Lowe’s.

Despite the settlement, Lowe’s continues to maintain it did not sell any Chinese-made drywall, which has been linked to corrosion and other problems seen in homes around the country. When it announced an earlier version of the settlement, the company said it “entered into this agreement as part of our commitment to serving our customers.”

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Fukushima Daiichi Nuclear Accident Update (25 March, 15:45 UTC)
Japanese authorities have informed the IAEA that on March 24, examinations of the thyroid glands in 66 children (14 of which are infants) were conducted near the evacuation area around the Fukushima nuclear plant. The exams were conducted at the Kawamata Town Health Center (40-50 kilometres from Fukushima Daiichi NPP) and Kawamata Town Yamakiya Branch Office (30-40 kilometres from Fukushima Daiichi NPP).

According to a 25 March 2011 Nuclear and Industrial Safety Agency press release, the results of the examinations indicated that the dose rate "of all the 66 children including 14 infants from 1 to 6 years old had no big difference from the level of background and was at the level of no problem in light of the view of Nuclear Safety Commission."

Regarding developments at the Fukushima Daiichi nuclear power plant, 'white smoke' was reported at Units 1, 2 and 4 from 21:20 UTC on 24 March. Sea water injection to Units 1, 2, 3 and 4 continues as of 23:00 UTC 24 March. The IAEA is seeking further information on the latest status of all Units and spent nuclear fuel at Fukushima Daiichi NPP.

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Average Yearly Ionizing Radiation Doses Caused by the Chernobyl Disaster

Chernobyl (1992) 490 millirem
Pripyat (1992) 2,500 millirem * ETA this is closer to the reactor site than Chernobyl

Average Yearly Ionizing Radiation Doses, at Sites in the World Where it is Highest, Due to Natural Causes

Average in Poland 240 millirem
Grand Central Station, New York City 540 millirem
Kerala, India 900 millirem
A region in Norway 1,000 millirem
A region in Sweden 3,500 millirem
Guarapari, Brazil 3,700 millirem
Tamil Nadu, India 5,300 millirem
Ramsar, Iran 8,900-13,200 millirem, in a house more than 100 years old

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"It bears repeating that in regions high in natural background radiation, no studies have found a radiation-induced increase of cancers and hereditary diseases."

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Abstract—People in some areas of Ramsar, a city in northern
Iran, receive an annual radiation absorbed dose from background
radiation that is up to 260 mSv y
1, substantially
higher than the 20 mSv y
1 that is permitted for radiation
workers. Inhabitants of Ramsar have lived for many generations
in these high background areas. Cytogenetic studies show
no significant differences between people in the high background
compared to people in normal background areas. An
in vitro challenge dose of 1.5 Gy of gamma rays was administered
to the lymphocytes, which showed significantly reduced
frequency for chromosome aberrations of people living in high
background compared to those in normal background areas in
and near Ramsar. Specifically, inhabitants of high background
radiation areas had about 56% the average number of induced
chromosomal abnormalities of normal background radiation
area inhabitants following this exposure. This suggests that
adaptive response might be induced by chronic exposure to
natural background radiation as opposed to acute exposure to
higher (tens of mGy) levels of radiation in the laboratory.
There were no differences in laboratory tests of the immune
systems, and no noted differences in hematological alterations
between these two groups of people.
Health Phys. 82(1):87–93; 2002
Key words: health effects; naturally occurring radionuclides;
radiation, background; exposure, population

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Today's work for cooling the spent fuel pools

-At :05 am, March 25th, we started injecting seawater into the spent fuel pool of Unit 4, using Fuel Pool Cooling and Filtering(clean up) system (FPC) and finished at 10:20 am.

At 10:30 am, March 25th, we started injecting seawater into the spent fuel pool of Unit 2, using Fuel Pool Cooling and Filtering (clean up) system (FPC) and finished it at 0:19 pm of the same day.

-Spraying at the spent fuel pool of Unit 3 by Kawasaki City Fire Department was carried out from 1:28 pm to 4:00 pm on March 25th.

-From 7:05 PM to 10:07 PM, Mar 25, water discharge by concrete pumping vehicle to the spent fuel pool of Unit 4 was conducted.

-We are considering further spraying at other units and others subject to the conditions of spent fuel pools.

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UPDATE AS OF 7:00 P.M. EDT, MARCH 25:
Fresh water is being injected into the reactor pressure vessel at reactor 3 at Fukushima Daiichi nuclear power plant, Japan's Nuclear and Industrial Safety Agency said.

TEPCO said that radioactive materials discovered at the reactor 3 turbine building possibly came from water from the reactor system, not the spent fuel pool. TEPCO made that statement after collecting samples of contaminated water in the reactor 3 turbine building and conducting a gamma-emitting nuclide analysis of the sample. The reactor pressure and drywell pressure at reactor 3 remained stable on Friday, leading TEPCO to believe that "the reactor pressure vessel is not seriously damaged.

Cooling efforts at Reactor 1 already had switched back to fresh water cooling. Reactor 2 is still being injected with seawater, but is expected to switch to fresh water soon.

Tokyo Electric Power Co. said that crews continued spraying water into the used fuel storage pools at reactors 3 and 4 on Friday to keep the used uranium fuel rods safe. Also on Friday, the heat removal system at reactor 6 was switched to a permanent power supply, NISA added.

TEPCO said it was assessing the radiation dose to two workers who were contaminated while laying cable in the turbine building of reactor 3. TEPCO said it had instructed its employees and contract workers to pay attention to their personal radiation dosimeter alarms and evacuate when necessary.

On-site radiation monitoring at the Fukushima Daiichi nuclear power plant indicates that radiation dose rates continue to decrease, the International Atomic Energy Agency said.

Radiation Monitoring Update

Air and seawater sampling continues by the Japanese government. Measurements in the ocean were taken 30 kilometers off-shore and 330 meters from the discharge points on March 23 and March 24. Results indicate concentrations of iodine-131 at 2,162 picocuries per liter and cesium-137 at approximately 703 picocuries per liter. Adult consumption of 1,000 picocuries (1 picocurie is one-trillionth of a curie) per liter concentration for 30 days will result in 24 millirem of radiation dose. For comparison, a typical dose from a chest x-ray is 10 millirem.

The concentrations found in the seawater samples are most likely "due to atmospheric fallout rather than just ocean currents," IAEA said. Dilution is expected to rapidly decrease this surface contamination, IAEA added.

Iodine-131 was detected in drinking water in 13 prefectures and cesium-137 was detected in drinking water in six prefectures. All results remained below the limits set by the Japanese government, IAEA said. Iodine-131 levels in drinking water in Tokyo are now below limits for consumption by infants set by the Japanese authorities and restrictions have been lifted.

On March 25, the IAEA radiation monitoring team made additional measurements at distances from 34 to 62 kilometers from the Fukushima Daiichi nuclear power plant. At these locations, the radiation dose rate was at extraordinarily low levels, ranging from 0.073 millirem per hour to 0.88 millirem per hour.

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IAEA Briefing on Fukushima Nuclear Accident (25 March 2011, 15:30 UTC)
On Friday, 25 March 2011, Graham Andrew, Special Adviser to the IAEA Director General on Scientific and Technical Affairs, provided the following information on the current status of nuclear safety in Japan.

1. Current Situation

There has not been much change at the Fukushima Daiichi plant over the last 24 hours. Some positive trends are continuing, but there remain areas of uncertainty that are of serious concern.

Unit 1 is with offsite AC power to the lighting of its central control room and to some of its instrumentation. Unit 3 now also has lighting to its central control room, but not power to its instrumentation. It remains too early to evaluate how much instrumentation may effectively be recovered at Units 1, 2, 3 and 4.

Reactor pressure is decreasing at Unit 1 and so is seawater injection. On the other hand, pressure readings in the reactor pressure vessels remain unreliable in Unit 2 and have become unreliable in Unit 3.

The temperature at the feed-water nozzle of the reactor pressure vessel continues to decrease (to 205 °C) at Unit 1, and at Unit 3 (42.8 °C), and it remains stable at Unit 2 (105 °C).

The dose rates in the containment vessel and suppression chamber have continued to decrease at Unit 1, and remained stable at Unit 2.

At Unit 3, radiation exposure of three TEPCO subcontracting workers has been confirmed. They were working in the basement, with contaminated water on the floor. Two of them were transferred to hospital with contamination of their feet.

There are no significant developments to report at Unit 4, where water spraying continues.

Units 5 and 6 remain in comparatively good condition. Temperatures at both, which had risen when the cooling pumps were briefly shut down in order to switch to off-site power, temperatures have since been restored to lower levels, and both units are still in cold shutdown. For the same reasons, a brief rise in temperature also occurred at the Common Spent Fuel Pool on 24 March.

2. Radiation Monitoring

On-site radiation monitoring at the Daiichi NPP indicates that dose rates continue to decrease.

Deposition of radioactivity is monitored daily by Japanese authorities in all 47 prefectures. From 23 March to 24 March, additional deposition has been detected in 7 of the 47 prefectures. Considerable variations are observed, the deposition at this day ranged from 42 to 16,000 Becquerel per square metre for iodine-131; the highest value determined for caesium-137 was 210 Becquerel per square metre. For the Shinjuku district of Tokyo, the deposition of iodine-131 on this day increased by 13,000 Becquerel per square metre, and the caesium-137 deposition by 160 Becquerel per square metre.

As far as the marine environment is concerned, sampling of air and seawater continues to be carried out by the Japanese Ministry of Education, Culture, Sport, Science and Technology (MEXT). Results are sent to the IAEA Monaco laboratory for assessment.

Measurements in the marine environment have been carried out 30 km off-shore and 330 metres from the discharge points on 23 March and repeated the next day. The results made available up to 25 March indicate concentrations of iodine-31 (some 80 becquerel/litre) and caesium-137 (about 26 becquerel/litre). This contamination is most likely due to atmospheric fallout rather than just ocean currents. Dilution in the ocean is expected to decrease rapidly this initial surface contamination. Caesium-137 will be more important over the long term owing to its half-life (30 years) compared to that of iodine-131 (8 days). Modelling of the dispersion of these radionuclides has been started, and the first results are becoming available. Marine dispersion will of course be much slower than atmospheric transport.

Since yesterday, additional data has been made available by the Japanese authorities concerning radionuclide concentrations in milk, vegetables and drinking water.

Levels of iodine-131 exceeded levels recommended by the Japanese authorities in five raw milk samples taken in Fukushima Prefecture, and exceeded levels of iodine-131 and cesium-137 in one vegetable (mizuna) sampled in Ibaraki Prefecture.

Monitoring of drinking water is on-going, iodine-131 in drinking water was detected in 13 prefectures, caesium-137 was detected in 6 of the 47 prefectures. During the period of 19 to 23 March, all results remained below the limits set by the Japanese government. However, permissible levels of iodine-131 were exceeded in drinking water samples taken in the Fukushima and Ibaraki Prefectures and in Tokyo from 17 to 23 March. More positively, the iodine-131 levels in drinking water for Tokyo are now below limits for consumption for infants recommended by the Japanese authorities and restrictions have been lifted.

As a result of food monitoring where contamination exceeded the levels recommended by the Japanese authorities, current restrictions on the distribution of milk are in place in 2 prefectures (Fukushima, Ibaraki) and on the distribution of certain vegetables in 4 prefectures (Fukushima, Ibaraki, Tochigi, Gunma). This regulatory approach is to prevent food contaminated with radioactivity above these limits entering the market and thereby, ensure the safety of foods. On 23 March, the Japanese authorities requested sampling of agricultural products in 6 neighbouring prefectures (Miyagi, Yamagata, Saitama, Chiba, Niigata and Nagano). This request for further food monitoring covers the same types of foods currently under restriction.

The joint FAO/IAEA food safety mission is currently travelling to Japan.

On 25th March, the IAEA radiation monitoring team made additional measurements at distances from 34 to 62 km from the Fukushima nuclear power plant. At these locations, the dose rate ranged from 0.73 to 8.8 microsievert per hour. At the same locations, results of beta-gamma contamination measurements ranged from 0.07 to 0.96 Megabecquerel per square metre.

Director General Amano had a video conference today with the UN Secretary General and the Heads of a number of other UN system organizations concerning the accident. In addition, close coordination led by the IAEA through the Joint Radiation Emergency Management Plan of International Organizations (JPLAN) continues.

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Status of Fukushima Daiichi nuclear power station as of 13:00, March 26, 2011
Here is information regarding the status of Fukushima Daiichi nuclear power station from the news reports aired by NHK in this morning on March 26 and last night.

&#56256;&#56442; High level of radioactive iodine was detected in the seawater sample corrected 330m away from the seawater discharge outlet. Iodine density of the sample is almost 1,250 times as much as legal standard. (11:35, March 26)

&#56256;&#56442; The work to switch source of water to be injected to reactor from seawater to freshwater is in progress. Nuclear and Industrial Safety Agency told that source of water to be injected to the spent fuel pool will be switched to freshwater also on March 27. TEPCO is trying to switch injecting water to freshwater, concerning that salt accumulated in a reactor would prevent water from flowing if seawater injection was continued for long periods of time. (11:35, March 26)

&#56256;&#56442; It is found that water accumulated at the basement of the turbine building of unit-1 and 3 contains radioactive material 10,000 times as much as it in water in reactor at normal operation. TEPCO took immediate action to drain off this water since current situation would cause delay in recovery work. (11:35, March 26)

&#56256;&#56442; Fukushima Daiichi nuclear power station has been in serious condition since some units lost cooling function. TEPCO is trying to recover components for cooling that should be driven by external AC power. However, working condition in high radiation area is so bad and there is no prospect of accomplishing the work for this recovery. (05:15, March 26)

&#56256;&#56442; Source of water to be injected into the reactor was switched from seawater to freshwater at unit-1 and 3 in the afternoon on March 25. It is considered that saline matter from seawater injected to seawater would take adverse effect in recovering cooling function future. (21:17, March 25)

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Function of containing radioactive material inside the containment vessel
It is presumed that radioactive material inside the reactor vessel would have leaked outside the containment vessel at unit-1 and unit- 3, based on the investigation of the water sampled
at turbine building.

...

Cooling the Spent Fuel Pool
Steam like suibstance rose from the reactor building at unit 1, 2, 3 and 4 is being observed. operation of spraying water to the spent fuel pool is being conducted.

...

<March 25th>
06:45-10:20 Water injection to SFP via reactor water clean up system started in Unit 4
10:30-12:19 Water injection to SFP via reactor water clean up system started in Unit 2
15:37 Water injection to the reactor was switched from sweater to freshwater at unit-1
18:02 Source of water injection to the reactor was switched from sweater to freshwater at unit-3
<March 26th>
10:10 Source of water injection to the reactor was switched from sweater to freshwater at unit-3

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Fukushima Daiichi Nuclear Accident Update (26 March, 01:30 UTC)
Radioactive Materials Found in Japanese Seawater Sampling -- UPDATED

Japanese authorities today reported data on radiation samples collected 30 kilometres off shore of the Fukushima Daiichi nuclear power plant on 24 March, and the levels of iodine-131 and cesium-137 showed slight variations from data collected at the same locations on 23 March (see previous update.

A vessel from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) collected water samples at eight points 30 kilometres from the coastline and found measurable concentrations of iodine-131 and cesium-137. The iodine concentrations measured were about at Japanese regulatory limits, and the cesium levels were well below those limits.

The IAEA’s Marine Environmental Laboratory in Monaco has received the data and offered this preliminary analysis:

Dilution, both into deeper layers and by dispersion along the prevailing ocean currents will lead to a rapid decrease of the initial surface contamination.

For the short term, iodine-131 will be the relevant radionuclide as far as doses are concerned, but for the long term, cesium-137 will be the more important radionuclide in the marine environment. It will be possible to follow this nuclide over long distances for several years.

It can be expected that radionuclides will take months or years to reach other shores of the Pacific. The main transport of contamination takes place by atmospheric transport over long distances

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Fukushima Daiichi Nuclear Accident Update (26 March 2011, 10:30 UTC)
IAEA Sends Second and Third Teams to Japan to Aid Response to Nuclear Emergency

The IAEA has dispatched additional teams to Japan to assist in the response to the Fukushima Daiichi nuclear power plant emergency.

On 24 March, a team of IAEA specialists travelled to Japan, where they will continue efforts to supplement Japan's radiation monitoring efforts. Team members include worker radiation protection experts and safeguards department officials.

On 25 March, a joint IAEA/Food and Agriculture Organization team departed Vienna. The three-person team included the Head of the IAEA Food and Environmental Protection Laboratory, an IAEA soil scientist, and an FAO food safety specialist from FAO's headquarters in Rome.

This food contamination assessment team will provide advice and assistance on sampling and analytical strategies and will help interpret Japanese monitoring data.

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Status of Fukushima Daiichi nuclear power station as of 20:00, March 26, 2011
Here is information regarding the status of Fukushima Daiichi nuclear power station from the news reports aired by NHK in this morning on March 26 and last night.

&#56256;&#56442; TEPCO Fukushima office announced that lights are currently working in the main control room of the unit-2 at 16:40 on March 26, after external AC power was restored. Now, lights become available in the main control room of unit 1, 2 and 3 (18:03, March 26)

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UPDATE AS OF 1:30 P.M. EDT, MARCH 26
The first of two U.S. Navy barges with freshwater is scheduled to arrive today at an area off the coast of the Fukushima nuclear power plant in Japan. Together, the barges will provide a total of 500,000 gallons of fresh water to help with cooling at the storm-damaged reactor. The barges have been cleaned of fuel in order to transport freshwater.

"[The two barges] can hold up to approximately 300,000 gallons of freshwater each," said Lt. Cmdr. Michael Weatherford, operations officer to Command Fleet Activities Yososuka. However, "the maximum capacity is reduced to make the barges seaworthy for ocean travel."

Tokyo Electric Power Co. reported on Saturday that lights were turned on in the main control room of reactor 2.


UPDATE AS OF 9:30 A.M. EDT, MARCH 26
Japanese scientists yesterday detected higher levels radioactive iodine in seawater at water outlets near the Fukushima Daiichi nuclear power plant.

"Iodine 131 was detected at a level 1,250 times the national safety limit," Hidehiko Nishiyama of the Nuclear and Industrial Safety Agency said during a news conference. Officials said there is no immediate danger to residents near the plant from these levels.

Samples taken on Friday were significantly higher than those taken on Wednesday, which had 147 times the legal concentration of I-131. Authorities said the concentration of radioactive materials in the water will decrease as the water is diluted by ocean currents. Indeed, a sample taken at 8:50 a.m. on Friday had one-fifth the concentration of I-131 as the earlier measurement. Three subsequent measurements that morning showed fluctuation. All were below the highest level found at 8:30 a.m. on Friday.

"As of now, there is no report of adverse impact on the marine life, especially beyond kilometers [of the plant]," said Chief Cabinet Secretary Yukio Edano. "Experts say there is a very low possibility, but we must strengthen our monitoring."

Efforts to cool the reactors and fuel pools continues at the Daiichi site. Freshwater is now being used to cool reactors 1, 2 and 3 in lieu of seawater. Workers began injecting fresh water at reactors 1 and 3 on March 25 and at reactor 2 on March 26. Meanwhile, two U.S. Navy barges carrying 500,000 gallons of freshwater are en route to a port 37 miles south of the Fukushima plant.

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Fukushima Nuclear Accident Update (26 March 2011, 15:15 UTC)
The IAEA has been informed by Japanese authorities that fresh water is now being used in place of sea water to cool the reactor pressure vessels at Units 1, 2 and 3 at the Fukushima nuclear power plant. The switch to fresh water is preferable as it leaves fewer deposits in components and is less corrosive than sea water.

IAEA Briefing on Fukushima Nuclear Accident (26 March 2011, 14:30 UTC)
On Saturday, 26 March 2011, Graham Andrew, Special Adviser to the IAEA Director General on Scientific and Technical Affairs, provided the following briefing on the current status of nuclear safety in Japan:

1. Current Situation

The situation at the Fukushima Daiichi plant remains very serious.

The restoration of off-site power is still progressing and instrumentation is being tested in Units 1, 2 and 4.

At Unit 1, the main change is the injection of freshwater to the Reactor Pressure Vessel (RPV). The temperature measured at the bottom of the RPV is stable at 144 °C. Pressure in the RPV, containment vessel and suppression pool have come back down after having increased from 22 to 24 March.

At Unit 2, the injection of freshwater to the RPV commenced at 01:00 on 26 March. The RPV temperature is stable at 100 °C at the bottom of the RPV. The pressure measured in the RPV and in the containment pressure vessel is stable at circa one atmosphere. Freshwater is also being injected in the RPV of Unit 3. Temperature measurement at the feed-water nozzle of Unit 3's RPV is still judged to be unreliable, but at the bottom of the RPV it is stable at 102 °C. White "smoke" continues to be emitted as of 23:00 UTC on 25 March from Unit 3, as it does from Unit 4. Unit 3 shows a consistently low containment drywell pressure of circa 1 atmosphere.

There have been high radiation readings in Units 1 and 3, the likelihood of damage to the containment integrity of Unit 3 is a cause for concern.

We understand that a total of 17 TEPCO workers and contractors have received doses between 100 and 180 millisievert. TEPCO measured the dose rate of 400 millisievert per hour above the surface of the water in the Unit 3 turbine building where 2 workers had been contaminated.

Units 5 and 6 are still in cold shutdown, with slight variations in RPV water temperatures (down a few degrees at Unit 5, up a few at Unit 6).

2. Radiation Monitoring

Deposition of radioactivity is monitored daily by Japanese authorities in all 47 prefectures. From 24 to 25 March, the daily level of deposition decreased in all but one prefecture. The highest value was observed in the prefecture of Ibaraki, where on 25 March a deposition of 480 becquerel per square metre for iodine-131 was observed; the highest value for caesium 137 was measured in Yamagata at 150 becquerel per square metre. For the Shinjyuku district of Tokyo, the additional deposition of iodine-131 and caesium-137 on 25 March was below 200 becquerel per square metre.

Monitoring of the marine environment has continued. New data for 21 to 25 March on radionuclide concentrations were made available for the discharge area 330 metres south of the pipeline of Fukushima Daiichi. The levels are generally quite high and vary significantly with time. The highest levels were detected at 25 March with, for example, 50 000 becquerel per litre of iodine-131, 7,200 becquerel per litre of caesium-137, and 7 000 becquerel per litre of caesium-134. Other short lived radionuclides were also reported. No new data has been reported by Japan from the monitoring stations located about 30 km offshore.

Monitoring of drinking water is on-going: iodine-131 in drinking water was detected on 24 March in 12 prefectures, whereas caesium-137 was detected in 6 of the 47 prefectures. In Tochigi, a value of 110 becquerel per litre was observed, which is above the recommended value for drinking water to be consumed by infants (i.e. 100 becquerel per litre). All other measurements were far below 100 becquerel per litre. All caesium-137 concentrations measured were lower than 10 becquerel per litre, which is significantly below the limit set by Japan of 200 becquerel per litre.

Environmental monitoring of soil, surface water, vegetation and air continues to be carried out in the Fukushima prefecture. The monitoring results indicate high levels of contamination. The values reported are generally consistent with measurements of gamma dose rates and beta-gamma contamination carried out by an IAEA monitoring team.

Two IAEA teams are currently monitoring in Japan. One team made gamma-dose rate measurements in Tokyo and the south of Tokyo in the prefecture of Kanagawa. Gamma-dose rates ranged from 0.05 to 0.2 microsievert. Another monitoring team made additional measurements at distances of 23 to 97 km (in a southerly and south westerly direction) from the Fukushima nuclear power plant. At these locations, the dose rates ranged from 0.73 to 8.8 microsievert per hour. At the same locations, results of beta-gamma contamination measurements ranged from 0.02 to 0.4 Megabecquerel per square metre.

Two prefectures (Ibaraki, Tochigi) reported iodine-131 in unprocessed raw milk, but the measurement results were below the regulation values set by the Japanese authorities. In addition, iodine-131 was not detected in any of the samples taken from the remaining four prefectures (Chiba, Gunma, Kanagawa and Saitama) and Tokyo. Caesium-137 was not detected in any of the samples.

For two prefectures (Ibaraki, Tochigi) iodine-131 and cesium-137 were reported in spinach and other leafy vegetables above the regulation values set by the Japanese authorities. However, iodine-131 and caesium-137 were either not detected or were below the regulation values, in all of the samples taken from the remaining four prefectures (Chiba, Gunma, Kanagawa and Saitama) and Tokyo. In all six prefectures and Tokyo, no iodine-131 and caesium-137 were detected in leeks, or measurements were well below the regulation values set by the Japanese authorities.

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