Stallion Cornell's Moist Board

Radiation Plume Modelers Chafe at Scarcity of Data



Atmospheric modelers are still warily watching the spread of radionuclides from the stricken Fukushima nuclear plant as workers there struggle to bring the situation under control. "The wind is blowing everything out to sea, so they've been lucky so far," says Andreas Stohl of the Norwegian Institute for Air Research. Modelers' biggest problem at the moment is scant knowledge of how much radioactive material is actually escaping from Fukushima.

"The data flow is very incoherent," Stohl says. The weather is also causing concern as the forecasts currently show a change in wind direction on Sunday night and Monday that could blow contamination toward Tokyo. "Things may change in the meanwhile," says Gerhard Wotawa of Austria's Central Institute for Meteorology and Geodynamics in Vienna. "But if the worst happens [at the plant], then that could cause problems there [in Tokyo]."

Modelers have to first estimate how much material is coming from the Fukushima plant, known as the "source term," and then take current wind field data provided by, for example, the European Centre for Medium-Range Weather Forecasts. Then they plug all this into an atmospheric model to predict how the material will spread over the coming days. Stohl says information on the source term is so scarce that his model has had to rely in part on media information. Wotawa, on the other hand, has access to data from radionuclide sensors belonging to the Comprehensive Test Ban Treaty Organization for his model.

CTBTO has a network of different types of sensors scattered around the globe to detect signs of clandestine nuclear cheats. Of the 60 radionuclide stations currently operating, there are more than 20 on islands in the Pacific and around the Pacific Rim. Such sensors would be a valuable resource when dealing with a nuclear accident, but the organization's mandate says the information can be given only to signatory governments, not released publicly. CTBTO radionuclide stations test for radioactive particles; air filters are checked once daily with a gamma-ray detector to identify what radionuclides may be present and in what quantities. It takes 2 or 3 days for the information to get to the signatory governments. Wotawa says that there were problems with early data from one of the two stations in Japan this week, first because of a power failure following the earthquake and then because of contamination of the filter. Those problems have now been resolved and he is expecting the latest data tomorrow.

Based on the radionuclide data he has received so far, he believes none of the Fukushima reactors has experienced a full meltdown. Most of what has been detected have been volatile isotopes, including iodine, cesium, and xenon. A meltdown would have added less volatile elements to the mix, such as zirconium and barium, and these haven't been detected in large quantities.

Because of the source term uncertainties, all the dispersion models can do is give "qualitative advice on where the plume is going," says Stohl. Thus far, most has been blown out to sea and is unlikely to reach places like North America in significant concentrations because of three factors:

* Much of the matter has a short half-life and decays away over a few days.

* The plume often gets lifted up into the upper troposphere by anticyclones.

* The plume gets more and more diluted the farther it travels.

Stohl says the material will likely be measurable in the United States and Europe but not in any concentrations that will impact on human health.

The change in wind direction forecast for the end of Sunday is causing some concern, however. Stohl says a cold front is forecast to pass over Japan and the wind will start blowing from the north and that may continue for a couple of days. "If it blows over populated areas, there could be a problem," Wotawa says. "And in combination with rain the contamination would be more severe." With the amount of material currently coming from the reactors, this would require Tokyo residents to stay indoors for only a couple of days, Wotawa believes. And this is still only a tentative prediction. "It can be very difficult to make reliable predictions of processes such as the dispersion through the atmosphere in view of the variability of the wind speed and direction on the short term," says Luigi Monte of the Italian nuclear agency ENEA.

Early Radiation Data From Near Plant Ease Health Fears




The first radiation measurements from within a 37-mile radius of the disabled Fukushima Dai-ichi power plant do not reveal any immediate health threat — and perhaps not even any health problems measurable decades from now, if levels stay where they are.

This may surprise people who assume that radioactivity in the vicinity of the plant must be dangerous, since radiation levels inside the plant are so high that workers can stay outside for only minutes at a time.

"This is very important information," says Hiroshima-based researcher Evan Douple, who has been studying the health of atomic bomb survivors for decades.

Douple says the new radiation levels, shown to him by NPR, "should be reassuring. At these levels so far, I don't think a study would be able to measure that there would be any health effects" — even years from now.


The radiation levels come from 46 monitoring posts scattered around the vicinity of the devastated power plant, from 12 miles to about 37 miles away. The readings were taken at two or three time points on Thursday and Friday and posted on the website of the Ministry of Education, Culture, Sports, Science and Technology. They're the first systematic, ground-level measurements to be made public since the crisis began last weekend.

The general picture is that radiation levels in the vicinity of the power plant are close to "background" levels at some locations. A background level is ever-present, low-level radiation given off by rocks, cosmic rays, fossil fuels and other natural sources. It accounts for about half the radiation exposure everyone gets, with medical tests accounting for the other half.

"Readings 10 times above background I don't think one would bat an eyelash at, really," says David Brenner, director of Columbia University's Center for Radiation Research.

The only exception to the generally low-level radiation measurements are from three monitoring posts northwest of the power plant that have measured levels 50 to 170 times higher than the other posts.

These three posts are clustered together at a point about 18 miles from the power plant.

It's not clear, experts said, that these higher levels have anything to do with emissions from the nuclear power plant. Radiation levels are affected by natural circumstances, such as rock outcroppings. Human activities can also raise local radiation levels, such as what appears to be a large strip-mining operation 13 miles northwest of the Fukushima power plant.

Douple, head of research at the Radiation Effects Research Foundation, a 60-year-old project funded jointly by the U.S. and Japan, calculates that if someone spent three weeks at the spot with the highest current radiation levels in this area of Fukushima prefecture, that individual would get 100 millisieverts of radiation.

That's about the same as having 10 abdominal CT scans. Douple calculates that, over decades, a 100 millisievert dose would result in one additional case of cancer among a group of 100 people with the age profile of the U.S. population. That is, instead of 42 cancers normally expected among these 100 people by the age of 70, there would be 43 cases.

"There are no health risks here," Brenner agrees. "If these numbers were to continue for the next week or two, there's still no immediate health risk."

As for the long term, he says, "whenever you get any increase in radiation dose, there will be a small elevation in cancer risk, but it would be very small."

Looking at it another way, a person could spend an entire year at this Fukushima "hot spot" and still not receive a lethal dose of radiation, although he might suffer some radiation symptoms, such as nausea.

Both Douple and Brenner raise a number of caveats about the new data.

* It's not clear what the natural background levels of radiation are in this part of Fukushima prefecture. This would be necessary to know in judging whether the levels recorded this week are likely to be due to emissions from the power plant.
* There is no information so far on the types of radiation at these measuring posts. This could indicate whether the radioactivity is from radioisotopes such as iodine-131 or cesium-137 emanating from nuclear fuel rods in damaged reactor cores or spent fuel pools.
* None of the measurements so far are from monitoring posts located between the power plant's perimeter and a 12-mile radius from the plant — an area from which 170,000 residents have been evacuated. If levels are higher within this ring, that could be a clue that plant emissions are responsible.

Still, Brenner says, "this is good stuff. If we had a map like this every day for the next week — and maybe we will — I think we will really start to see trends. We need this information, and we need it over time."

Although it's too soon to call it a trend, there is a difference in the measurements at the three hot spot posts between Thursday and Friday. They went down over that 24-hour period. For instance, at monitoring post No. 31, levels went down from around 0.06 millisieverts per hour on Thursday to around 0.045 on Friday. At post No. 32, readings went down from as high as 0.17 on Thursday to 0.15 on Friday.

But at this point, it's impossible to say whether that's due to the instruments or the methods of measurement — or to true fluctuations in the radiation level.
Chart of radiation sources and effects

Credit: Alyson Hurt and Andrew Prince/NPR

For comparison, an airline passenger on a flight from New York to Los Angeles would get 0.2 millisieverts of radiation from high-altitude cosmic rays.

By contrast, newly released radiation levels at the power plant were vastly higher — 3.6 millisieverts on Thursday morning in the middle of the plant, and 0.647 millisieverts at the plant's main gate.

Cooling function operable at 2 reactors

The government says parts of the cooling systems at 2 of the 6 reactors at the Fukushima Daiichi nuclear power plant have been confirmed to be operable.

The Nuclear and Industrial Safety Agency told a news conference on Saturday that an emergency diesel generator at the No. 6 reactor has resumed operation.

The agency also said that a cooling pump, at the No. 5 reactor, has been confirmed to be usable, and that workers started cooling the spent fuel storage pool there at 5 AM on Saturday.

The agency said the radiation level at the west gate of the plant, located about 1.1 kilometers west of the No. 3 reactor, was relatively high at 830.8 microsieverts per hour at 8:10 AM. But it said the figure fell to 364.5 microsieverts at 9:00 AM.

Saturday, March 19, 2011 14:07 +0900 (JST)

Efforts to restore cooling function continue at nuke plant

TOKYO, March 19, Kyodo

Japan on Saturday continued efforts to contain the quake-triggered crisis at a nuclear power plant, with Tokyo Electric Power Co. trying to bring electricity back to its crippled nuclear reactors in the hope of restoring their cooling functions, while firefighters again threw water to cool down overheating spent fuel pools.

Connecting a power line to the No. 2 reactor of the Fukushima Daiichi power plant is expected to be completed during the day.

Restoring a stable source of electricity is a key step to prevent further deterioration of the situation by cooling down the reactor cores or water in the spent fuel tanks.

After smoke was detected from the No. 3 reactor building on Wednesday, Self-Defense Forces, fire fighters and others have engaged in an unprecedented mission to spray massive amounts of water at the damaged building so that the spent fuel pool located inside would fill with water, which is vital to prevent radioactive release.

The Tokyo Fire Department, including disaster relief specialists of its ''hyper rescue'' team, discharged 60 tons of water early Saturday and resumed the work in the afternoon and continued shooting water for seven hours. But the firefighters are believed to have left the water cannon truck unmanned apparently out of concerns over the radiation level in the area.

The Tokyo Fire Department said the dose that workers were exposed to so far was not ''at a level that would affect health.''

Meanwhile, a Ground Self-Defense Force helicopter flew over the troubled Daiichi plant Saturday morning to check the changes in temperatures at its reactors using thermography, the Defense Ministry said.

The CH47 chopper also examined what effect the water sprayed on the reactor had in cooling the spent fuel pool, it said.

A rise in water temperature, usually to 40 C, causes the water level to fall, thus exposing the spent nuclear fuel rods, which could then heat up further, melt and discharge highly radioactive materials in the worst-case scenario, experts say.

According to the plant operator Tokyo Electric, the maximum earthquake intensity measured at the nuclear power plant was 507 gals at the No. 3 reactor building, smaller than 600 gals the nuclear plant is required to withstand. The data is a provisional figure.

The Nuclear and Industry Safety Agency has raised the severity level of the crisis-hit reactors to 5 from 4 on an international scale Friday, the same level as the Three Mile Island accident in the United States in 1979.

Among the six reactors at the Fukushima Daiichi Nuclear Power Station, the No. 1, No. 2 and No. 3 reactors, the only ones operating at the time of the magnitude 9.0 quake, halted automatically, but the cores are believed to have partially melted as the reactors lost cooling function after the quake.

The buildings housing the No. 1, No. 3 and No. 4 reactors have been severely damaged, leaving fuel pools there uncovered, and the No. 2 reactor's containment vessel suffered damage to its pressure-suppression chamber below.

The government has set an exclusion zone covering areas within a 20-kilometer radius of the plant and has urged people within 20 to 30 km to stay indoors.

SDF sprays water into No.3 reactor

The Self-Defense Forces have released a video of the operation to cool the No.3 reactor at the quake-hit Fukushima Daiichi nuclear power plant.

The SDF used helicopters and fire trucks to spray water into the spent fuel rod pool on Thursday and Friday.

The pool could no longer be cooled, raising the risk of a massive radioactive leak.

The footage shows the spraying of water from the ground, which was part of the operation that lasted for 40 minutes from shortly before 2 PM on Friday.

It also shows the situation around the No.3 reactor.

The 7-minute video was taken by a member of a special unit of the Ground Self-Defense Force.

Six special fire trucks from the SDF's air bases across the country and a fire truck that Tokyo Electric Power Company borrowed from the US military sprayed a total of 50 tons of water toward the No.3 reactor.

The Defense Ministry says the water reached inside the building.

Saturday, March 19, 2011 16:58 +0900 (JST)

Japan officials: radioactive iodine in Tokyo water
By MARI YAMAGUCHI, Associated Press Mari Yamaguchi, Associated Press 1 hr 30 mins ago

TOKYO – The government said Saturday that small but safe amounts of radioactive iodine turned up in tap water in Tokyo and five other areas, amid concerns about radiation leaking from a damaged nuclear power plant.

The trace amounts were found in Tokyo and the other prefectures on Friday, the first day since the government ordered nationwide daily sampling due to the nuclear crisis at the Fukushima Dai-ichi nuclear plant, the Ministry of Education, Culture, Sports, Science and Technology said.

A ministry statement said the amounts found did not exceed government safety limits. But tests on water, which for decades were only done once a year, usually show no iodine.

The highest reading was less than a third of the allowable limit. A ministry official, who could not be quoted by name as is customary, said the government deems the small amounts safe and was awaiting further expert analysis.

"The figure is still below the national limit and safe," said Masayuki Kubo, an environmental protection official at Tochigi prefecture, where the highest tap water reading was found. "You can drink it safely without limiting the amount of water you take."

Nuclear reactors at the Fukushima plant began leaking radiation in the days after the March 11 earthquake and tsunami knocked out its cooling systems. The crisis has raised public alarm about the threat to public heath, and earlier Saturday, the government acknowledged that tests found iodine in spinach and iodine and the radioactive element cesium in milk from some farms 20 to 75 miles (30 to 120 kilometers) from Fukushima.

The areas where iodine turned up in the tap water are well to the west and south of the nuclear plant.

Japan cites radiation in milk, spinach near plant
By SHINO YUASA and ERIC TALMADGE, Associated Press Shino Yuasa And Eric Talmadge, Associated Press 52 mins ago

FUKUSHIMA, Japan – In the first sign that contamination from Japan's stricken nuclear complex had seeped into the food chain, officials said Saturday that radiation levels in spinach and milk from farms near the tsunami-crippled facility exceeded government safety limits.

Minuscule amounts of radioactive iodine also were found in tap water in Tokyo and elsewhere in Japan — although experts said none of the tests showed any health risks.

The discovery came as officials said the crisis at the nuclear plant appeared to be stabilizing, with near-constant dousing of dangerously overheated reactors and uranium fuel, but the situation was still far from resolved.

"We more or less do not expect to see anything worse than what we are seeing now," said Hidehiko Nishiyama of the Nuclear and Industrial Safety Agency.

Japan has been grappling with a cascade of disasters unleashed by the 9.0-magnitude earthquake on March 11. The quake spawned a tsunami that ravaged Japan's northeastern coast, killing more than 7,300 people and knocking out cooling systems at the Fukushima Dai-ichi nuclear plant, causing the complex to leak radiation.

Nearly 11,000 people are still missing, and more than 452,000 are living in shelters.

Chief Cabinet Secretary Yukio Edano, meanwhile, insisted the contaminated foods "pose no immediate health risk."

The tainted milk was found 20 miles (30 kilometers) from the plant, a local official said. The spinach was collected from six farms between 60 miles (100 kilometers) and 75 miles (120 kilometers) to the south of the reactors.

Those areas are rich farm country known for melons, rice and peaches, so the contamination could affect food supplies for large parts of Japan.

More tests was being done on other foods, Edano said, and if they show further contamination, then food shipments from the area would be halted.

Officials said it was too early to know if the nuclear crisis caused the contamination, but Edano said air sampling done near the dairy showed higher-than-normal radiation levels.

Iodine levels in the spinach exceeded safety limits by three to seven times, a food safety official said. Tests on the milk done Wednesday detected small amounts of iodine-131 and cesium-137, the latter being a longer-lasting element that can cause more types of cancer. But only iodine was detected Thursday and Friday, a Health Ministry official said.

After the announcements, Japanese officials immediately tried to calm an already-jittery public, saying the amounts detected were so small that people would have to consume unimaginable amounts to endanger their health.

"Can you imagine eating one kilogram of spinach every day for one year?" said State Secretary of Health Minister Yoko Komiyama. One kilogram is a little over two pounds.

Edano said someone drinking the tainted milk for one year would consume as much radiation as in a CT scan; for the spinach, it would be one-fifth of a CT scan. A CT scan is a compressed series of X-rays used for medical tests.

Masayuki Kubo, an environmental protection official in Tochigi prefecture, where the highest tap water reading was found, said the water was also safe.

"You can drink it safely without limiting the amount of water you take," Kubo said.

At the Fukushima plant, emergency workers have been struggling to cool the reactors and the pools used to store used nuclear fuel, as well as to put the facility back on the electricity grid.

A replacement power line reached the complex Friday, but workers needed to methodically work through badly damaged and deeply complex electrical systems to make the final linkups without setting off a spark and potentially an explosion. Company officials hoped to be able to switch on the cooling systems Sunday.

Once the power is reconnected, it is not clear if the cooling systems will still work.

A fire truck with a high-pressure cannon pumped water directly from the ocean into one of the most troubled areas of the complex — the cooling pool for used fuel rods at the plant's Unit 3. Because of high radiation levels, firefighters only went to the truck every three hours to refuel it.

Holes were also punched in the roofs of units 5 and 6 to vent buildups of hydrogen gas, and the temperature in Unit 5's fuel storage pool dropped after new water was pumped in, according to officials with Tokyo Electric Power Co., which owns the complex.

More workers were thrown into the effort — bringing the total at the complex to 500 — and the safety threshold for their radiation exposure was raised 2 1/2 times so they could keep working.

Officials insisted that would cause no health damage.

Edano said conditions at the reactors in Units 1, 2 and 3 — all of which have been rocked by explosions in the past eight days — had "stabilized."

The reactors and the storage pools both need constant sources of cooling water. Even when they are taken from reactors, uranium rods remain very hot and must be cooled for months, possibly longer, to prevent them from heating up again and emitting radioactivity.

Low levels of radiation have been detected well beyond Tokyo, which is 140 miles (220 kilometers) south of the plant, but hazardous levels have been limited to the plant itself.

People evacuated from around the plant, along with some emergency workers, have tested positive for radiation exposure. Three firefighters needed to be decontaminated with showers, while among the 18 plant workers who tested positive, one absorbed about one-tenth of the amount that could induce radiation poisoning.

Outside the bustling disaster response center in the city of Fukushima, 40 miles (60 kilometers) northwest of the plant, government nuclear specialist Kazuya Konno was able to take only a three-minute break for his first meeting since the quake with his wife, Junko, and their children.

"It's very nerve-racking. We really don't know what is going to become of our city," said Junko Konno, 35. "Like most other people, we have been staying indoors unless we have to go out."

She brought her husband a small backpack with a change of clothes and snacks. The girls — aged 4 and 6 and wearing pink surgical masks decorated with Mickey Mouse — gave their father hugs.

The government conceded Friday that it was slow to respond to the crisis and welcomed ever-growing help from the U.S. in hopes of preventing a complete meltdown.

Nishiyama, of the nuclear safety agency, also said backup power systems at the plant had been improperly protected, leaving them vulnerable to the tsunami.

The failure of Fukushima's backup power systems, which were supposed to keep cooling systems going in the aftermath of the earthquake, let uranium fuel overheat and were a "main cause" of the crisis, Nishiyama said.

"I cannot say whether it was a human error, but we should examine the case closely," he told reporters.

A spokesman for Tokyo Electric said that while the generators were not directly exposed to the waves, some electrical support equipment was outside. The complex was protected against tsunamis of up to 5 meters (16 feet), he said. Media reports say the tsunami was at least 6 meters (20 feet) high when it struck Fukushima.

Spokesman Motoyasu Tamaki also acknowledged that the complex was old, and might not have been as well-equipped as newer facilities.

The crisis has led to power shortages and factory closures, and triggered a plunge in Japanese stock prices.

On Saturday evening, Japan was rattled by 6.1-magnitude aftershock, with an epicenter just south of the troubled nuclear plants. The temblor, centered 150 kilometers (90 miles) northeast of Tokyo, shook buildings in the capital.

Japan says makes progress in nuclear crisis
By Taiga Uranaka and Yoko Nishikawa Taiga Uranaka And Yoko Nishikawa 58 mins ago

TOKYO (Reuters) – Japan saw some success in its race to avert disaster at a tsunami-damaged power plant, though minor radiation leaks underlined perils from the world's worst nuclear crisis since Chernobyl 25 years ago.

Three hundred engineers have been battling inside a danger zone to salvage the six-reactor Fukushima plant since it was hit by an earthquake and tsunami that also killed 7,653 people and left 11,746 more missing in northeast Japan.

The unprecedented multiple crisis will cost the world's third largest economy nearly $200 billion and require Japan's biggest reconstruction push since post-World War II.

It has also set back nuclear power plans the world over.

Encouragingly for Japanese transfixed on work at the Fukushima complex, the most critical reactor -- No. 3 which has highly toxic plutonium -- stabilized after fire trucks doused it for hours with hundreds of metric tons of water.

Work also advanced on bringing power back to water pumps used to cool overheating nuclear fuel.

"We are making progress ... (but) we shouldn't be too optimistic," said Hidehiko Nishiyama, deputy-general at Japan's Nuclear Safety Agency.

Technicians attached a power cable to the No. 1 and No. 2 reactors, hoping to restore electricity later in the day prior to an attempt to switch the pumps on.

They aim to reach No. 3 and 4 soon after that.

If successful, that could be a turning point in a crisis classed as bad as America's 1979 Three Mile Island accident.

If not, drastic measures may be required such as burying the plant in sand and concrete as happened at Chernobyl after the world's worst nuclear reactor disaster in 1986.

Facing criticism of its early handling of the situation, plant operator TEPCO's president issued a public apology for "causing such great concern and nuisance".

Even after restoring power, the company faces a tricky task reactivating the cooling pumps, with parts of the system probably damaged from the quake or subsequent explosions.

"The workers need to go through the plant, figure out what survived and what didn't, what can be readily repaired and get the cooling systems back up and running to deal with the cores and the spent fuel pools," said David Lochbaum, of U.S. nuclear watchdog the Union of Concerned Scientists.

FOREIGN ENCOURAGEMENT

Russia's Prime Minister Vladimir Putin recognized

Japan's progress during a trip to reassure residents of eastern regions there was no immediate danger from the nuclear accident.

"Our Japanese colleagues are gradually, not right away and with mistakes ... getting the situation under control," he said in the city of Yuzhno-Sakhalinsk. "The work is being done properly, in the right way -- 24 hours a day."

Putin proposed freeing up energy for Japan by increasing Russian gas supplies to Europe so more liquefied natural gas (LNG) cargoes could go to the Asian nation.

U.N. watchdog the International Atomic Energy Agency (IAEA) also offered encouragement to Tokyo. Its chief Yukiya Amano, who is Japanese, hailed the "strengthening" of work at the site.

On the negative side, evidence has begun emerging of radiation leaks from the plant, including into food and water.

Though public fear of radiation runs deep, and anxiety has spread as far as the Pacific-facing side of the United States,

Japanese officials say levels so far are not alarming.

Traces exceeding national safety standards were, though, found in milk from a farm about 30 km (18 miles) from the plant and spinach grown in neighboring Ibaraki prefecture.

The first discovery of contaminated food since the March 11 disaster is likely to heighten scrutiny of Japanese food exports, especially in Asia, their biggest market.

Tiny levels of radioactive iodine have also been found in tap water in Tokyo, one of the world's largest cities about 240 km (150 miles) to south. Many tourists and expatriates have already left and residents are generally staying indoors.

Prime Minister Naoto Kan, who has kept a low profile during the crisis except for shouting at plant operator Tokyo Electric Power Co (TEPCO), sounded out the opposition about forming a government of national unity to deal with the crisis.

But the largest opposition party rejected that.

MOVING EARTH

Showing the incredible power of the 9.0 magnitude earthquake, the largest in tremor-prone Japan's recorded history, Oshika peninsula in Miyagi prefecture shifted a whole 5.3 meters (17 ft) east and its land sank 1.2 meters (4 ft).

In contrast to the generally traumatic and negative images so far, one video emerged showing the crew of a Japanese coastguard vessel successfully riding a massive wave by turning the bow directly at the wall of waters.

The quake and ensuing 10-meter high tsunami devastated Japan's north east coastal region, wiping towns off the map and making more than 360,000 people homeless in a test for the Asian nation's reputation for resilience and social cohesion.

Food, water, medicine and fuel are short in some parts, and low temperatures during Japan's winter are not helping.

The traumatic hunt for bodies and missing people continues.

"This morning my next door neighbor came crying to me that she still can't find her husband. All I could tell her was, 'We'll do our best, so just hold on a little longer,'" said fire brigade officer Takao Sato in the disaster zone.

About 257,000 households in the north still have no electricity and at least one million lack running water.

Japan's crisis spooked markets, prompted a rare intervention by the G7 group of rich nations to stabilize the yen on Friday , and may disrupt supplies to auto and technology markets.

Automaker General Motors Co said it was suspending all nonessential spending and global travel, plus freezing production at a plant in Spain and cancelling two shifts in Germany while it assessed the impact of the Japan crisis.

6 workers exposed to excessive radiation at Fukushima plant

TOKYO, March 19, Kyodo

Six workers at the crisis-hit Fukushima Daiichi nuclear power plant have been exposed to radiation levels beyond the limit applied to an emergency operation, Tokyo Electric Power Co. said Saturday, without elaborating on the work that they were engaged in.

They are continuing to work on different tasks because they have not shown any abnormal signs since being exposed to over 100 millisieverts of radiation, the utility said. The limit has been raised to 250 millisieverts for the ongoing crisis, the worst in Japan's history, by the Health, Labor and Welfare Ministry.

The government's Fire and Disaster Management Agency said separately that readings of up to 27 millisieverts of radiation were detected as of noon on around 50 employees of the Tokyo Fire Department who were decontaminated after spraying water earlier in the day at the plant's highly dangerous No. 3 reactor.

==Kyodo

Police found two survivors

Police in Miyagi Prefecture say rescuers found 2 people under rubble in Ishinomaki City on Sunday, 9 days after the initial earthquake on March 11th.

Police say an 80-year-old woman and a 16-year-old boy responded to rescue workers.

Sunday, March 20, 2011 16:55 +0900 (JST)

Gases to be vented from No.3 reactor

Workers at the Fukushima Daiichi nuclear power plant are preparing to release gases from the overheating Number 3 reactor to lower pressure inside its container vessel.

The Nuclear and Industrial Safety Agency said on Sunday that pressure inside the vessel is rising despite efforts to cool the reactor.

The agency said the workers will first try to vent gases through a suppression pool to reduce the amount of radioactive substances released into the environment.

If the pressure doesn't decline, the officials will release gases directly from the vessel. If that happens, the level of radioactive iodine in the air will increase by 100-fold.

Reducing pressure is necessary to protect the container vessel, which keeps radioactive materials inside the reactor in case of an accident.

The plant operator, Tokyo Electric Power Company, says firefighters who are preparing to resume hosing water into the reactor and officials installing power cables will first be evacuated.

The agency says it agreed with the utility firm that it is absolutely essential to release gases despite the expected increase in radiation levels.

Sunday, March 20, 2011 15:16 +0900 (JST)

Water temperature drops in fuel rod pools

The water temperature is dropping in the spent fuel rod pools of the No.5 and No.6 reactors at the Fukushima Daiichi nuclear power plant.

The Tokyo Electric Power Company restored a power generator at the No.6 reactor on Saturday morning.

A backup generator at the reactor had been used since the quake to cool the spent fuel rod pools at both the No.5 and No.6 reactors.

But as water temperatures rose, a single generator was unable to supply enough power for the two reactors.

The newly restored generator is being used to activate a cooling pump in the No.5 reactor.

The power company measured the water temperature of the spent fuel pool in the No.5 reactor and found it had decreased from 68.8 degrees Celsius at 5 AM Saturday to 43.1 degrees at 3 AM Sunday.

After the cooling pump at the No. 6 reactor was restored, the water temperature dropped more than 15 degrees, from 67.5 degrees Celsius at 11PM Saturday to 52 degrees at 3 AM Sunday.

On the other hand, the water temperature of the reactor vessels is rising.

The water temperature was 194.5 degrees Celsius in the No.5 reactor and 152.4 degrees in the No. 6 reactor at 6 PM Saturday.

Those temperatures are lower than when the reactors are in operation, but they are increasing.

The power company says it will begin cooling the reactor water as soon as the spent fuel rod pools are cooled down.

It hopes to restore connections to external power sources to cool down the reactors in a stable manner.

Sunday, March 20, 2011 09:19 +0900 (JST)

Thanks for the updates. Some positive developments for a change.
And some ominous ones as well.

You probably are following all this on a TV so don't really need it I on the other hand do not have a TV so this is it!