March 30, 2011 at 10:51 pm By Roz Potter
A very important post from the Union of Concerned Scientists blog link
Cesium-137, which has a half-life of 30 years, has been found 40 km (25 miles) northwest of the Fukushima plant in concentrations much higher than those that triggered a compulsory evacuation after Chernobyl.
The IAEA is reporting that measured soil concentrations of Cs-137 as far away as Iitate Village, 40 kilometers northwest of Fukushima-Dai-Ichi, correspond to deposition levels of up to 3.7 megabecquerels per square meter (MBq/sq. m). This is far higher than previous IAEA reports of values of Cs-137 deposition, and comparable to the total beta-gamma measurements reported previously by IAEA and mentioned on this blog.
This should be compared with the deposition level that triggered compulsory relocation in the aftermath of the Chernobyl accident: the level set in 1990 by the Soviet Union was 1.48 MBq/sq. m.
March 21, 2011 at 11:25 pm By Roz Potter
We have now had four grave nuclear reactor accidents: Windscale in Britain in 1957 (the one that is never mentioned), Three Mile Island in the United States in 1979, Chernobyl in the Soviet Union in 1986, and now Fukushima. Each accident was unique, and each was supposed to be impossible. Nuclear engineers have learned from each accident how to improve reactor design so as to diminish the likelihood of that particular accident repeating itself but, as Donald Rumsfeld famously reminded us, there are always “unknown unknowns,” and so each accident has been succeeded by another, unwinding in a way that was not foreseen. The designers of the reactors at Fukushima did not anticipate that the tsunami generated by an earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake.
And presumably there are other complicated technological scenarios that we have not foreseen, earthquake faults that are undetected or underestimated, and terrorists hatching plans for mayhem as yet unknown. Not to mention regulators who place too much trust in those they regulate.
March 21, 2011 at 10:58 pm By Roz Potter
Radiation 1,600 times higher than normal levels has been detected in an area about 20 kilometers from the crippled Fukushima Daiichi nuclear power plant.
The International Atomic Energy Agency says its team of experts measured radiation in the air and soil at 11 locations in Fukushima Prefecture.
March 21, 2011 at 3:33 pm By Roz Potter
The Idaho Department of Environmental Quality has an informative chart on its website , that will give readers an idea of the average amount of radiation absorbed each year from food, water, natural gas powered stoves and heaters, medical x-rays and nuclear medicine procedures, proximity to nuclear power or coal fired power plants, smoking, flying in an airplane, and other sources.
There is several other nifty charts on the website including a personal yearly dose calculator.
These sources do provide welcome perspective.
March 19, 2011 at 9:30 pm By Roz Potter
“Situation on the site is getting better, but food issue is emerging.
The 1,200 tons of water sprayed on the storage pool of unit 3 seems to be having a positive impact. The Nuclear Industry and Safety Agency (NISA) reported that, 500 meters from the plant, the radiation level decreased from 3,443 microsieverts per hour to 2,906 microsieverts per hour; however, detailed analysis is still needed.
Meanwhile, units 1 and 2 are now connected to the grid. The equipment needs to be checked whether it is in working order.”
March 19, 2011 at 3:34 pm By Roz Potter
These WHO guidelines apply to those exposed to radiation in doses high enough to cause concern for health. This in not the current state of affairs outside of affected area of Japan, except perhaps for Japan’s neighbors. Health risks are dependent on the concentration of particles being disseminated, proximity to radiation source(s), ground wind, weather and atmospheric conditions. and the duration of exposure.
For those not currently at risk, this is good information to have on hand in the event of a nuclear accident or nuclear terrorism events within a distance that could cause health risks. Link
Radiation exposure and related information will be covered in the upcoming workshop on Earthquake and Nuclear/Radiological preparedness given Saturday, March 26 from 9 am to 12 pm, at the John Muir Inn in Napa. There will be a question and answer session
March 17, 2011 at 11:41 pm By Roz Potter
A bleak and realistic appraisal from the head of the U.S. Nuclear Regulatory Commission.
March 17, 2011 at 10:10 pm By Roz Potter
- Q. Why are potassium iodide tablets used during emergencies involving radiation exposure?
A. Potassium iodide tablets may be recommended to individuals who are at risk for radiation exposure or have been exposed to excessive radiation to block the body’s absorption of radioactive iodine. Using potassium iodide when inappropriate could have potential serious side effects such as abnormal heart rhythms, nausea, vomiting, electrolyte abnormalities and bleeding.
- Q. Should I be taking potassium iodide to protect myself?
A. No. Potassium iodide tablets are not recommended at this time, and can present a danger to people with allergies to iodine, shellfish or who have thyroid problems.
- Q. Should I purchase potassium iodide as a precaution?
A. No. Potassium iodide is only appropriate within a very close proximity to a nuclear event. Using potassium iodide when inappropriate could have potential serious side effects such as abnormal heart rhythms, nausea, vomiting, electrolyte abnormalities and bleeding.
March 16, 2011 at 1:44 pm By Roz Potter
Link . An important article.
After the explosions and fire, the Fukushima nuclear complex released radiation of up to 400 millisieverts per hour, Japanese officials have said. That would be about 20 times the annual exposure for some nuclear industry workers.
Dr. James Thrall, radiologist-in-chief at Massachusetts General Hospital in Boston and president of the American College of Radiology, said anything more than about 50 millisieverts may be cause for alarm, including the use of potassium iodide pills to mitigate exposure. Studies conducted after the atomic bombing of Japan during World War II showed those exposed to 50 millisieverts or more of radiation were at increased risk for leukemia and cancer, Thrall said.
March 15, 2011 at 8:37 pm By Roz Potter
There is little hope left of cooling down nuclear reactor rods in 4 reactors at Fukushima Dai-ichi plant and averting further meltdowns. There are reports of partial meltdowns at two reactors. Fuel rods at a third reactor have sustained damage and are releasing radioactivity directly into the atmosphere from a cooling pond. After yet another fire at the nuclear plant today, the fifth since the earthquake, radiation levels surged making work at the plant a suicide mission. All workers have been withdrawn. Helicopters and fire trucks will be used in a last ditch effort to cool down the reactors.
For the full story, Link
March 15, 2011 at 7:35 pm By Roz Potter
The monitors of gamma radiation and radioactive particles, will be set up in “parts of the Western U.S. and U.S. territories,” the agency said in a statement.
EPA officials, however, refused to answer questions or make staff members available to explain the exact location and number of monitors, or the levels of radiation, if any, being recorded at existing monitors in California. Margot Perez-Sullivan, a spokeswoman at EPA regional headquarters in San Francisco, said the agency’s written statement would stand on its own.
Critics said the public needs more information.
“It’s disappointing,” said Bill Magavern, director of Sierra Club California. “I have a strong suspicion that EPA is being silenced by those in the federal government who don’t want anything to stand in the way of a nuclear power expansion in this country, heavily subsidized by taxpayer money.”
For the full story, Link
March 15, 2011 at 3:02 pm By Roz Potter
CBS news reports that 2 workers are missing and a crack in the roof of reactor #4, has been discovered. There was an explosion at the reactor yesterday.
Although the fire in the pond where fuel rods are kept has been extinguished, water in the pond is boiling, releasing radioactive particles into the air. The fuel rod containers may have been damaged. The walls of the storage pool building were damaged, making containment of released radioactive particles impossible.
There is deepening concern and some outright panic in Japan and other vulnerable areas.
Read the story Link
March 15, 2011 at 2:40 pm By Roz Potter
A third explosions at the Fukushima Dai-ichi plant, ripped a 26 foot hole into in the reactor building and damaged the vessel below the reactor, but not the reactor core. The damaged vessel underneath the reactor will make it more difficult to control a meltdown, should it occur.
Three hours later, a fire erupted at a fourth reactor which has been offline. Steam with radioactive particles is being emitted directly into the atmosphere from nuclear fuel rods stored in a pool.
The US Navy has moved its ships to the east after detecting larger amounts of radioactivity than expected, through air monitoring. Several US military personnel were treated for radiation exposure.
140, 000 people living within 20 miles of the plant were ordered to seal themselves indoors until dangerous levels of radioactive emissions are under control. There is a ban on commercial air travel due to health concerns.
March 15, 2011 at 12:41 pm By Roz Potter
This is a UTube video. First a very solid explanation of events through yesterday by Maddow. Then Rachael is joined by David Lochbaum, the Director of the Nuclear Safety Project at the Union of Concerned Scientists. Link
March 15, 2011 at 1:16 am By Roz Potter
According to an article in the Los Angeles Times today, “the U.S. Department of Energy activated the National Atmospheric Release Advisory Center at Livermore to create sophisticated computer models of how the radioactive releases from Fukushima No. 1 would disburse into the atmosphere. The center, which was created to deal with contamination in the event of a nuclear war, played a key role in predicting contamination patterns during the 1986 Chernobyl nuclear crisis”. Link
March 15, 2011 at 12:09 am By Roz Potter
Two more reactors exploded today in Japan at the troubled Fkushima Daiichi plant. At a news conference held after the second blast, Japan’s Prime Minister advised that one explosion has caused damage to a reactor container vessel, resulting in significant radiation leakage outside the nuclear facility. Those injured also had to be treated for radiation exposure.
Today, the New York Times has written an article that pierces the newspeak and presents the current situation in clear terms. I urge you to read it.
The sudden turn of events, after an explosion Monday at one reactor and then an early-morning explosion Tuesday at yet another — the third in four days at the plant — already made the crisis at the Fukushima Daiichi Nuclear Power Station the worst nuclear accident since the Chernobyl reactor disaster a quarter century ago.
It diminished hopes earlier in the day that engineers at the plant, working at tremendous personal risk, might yet succeed in cooling down the most damaged of the reactors, No. 2, by pumping in sea water. According to government statements, most of the 800 workers at the plant had been withdrawn, leaving 50 or so workers in a desperate effort to keep the cores of three stricken reactors cooled with seawater pumped by firefighting equipment, while the same crews battled to put out the fire at the No. 4 reactor, which they claimed to have done just after noon on Tuesday.
…The two critical questions over the next day or so are how much radioactive material is spewed into the atmosphere, and where the winds carry it. Readings reported on Tuesday showed a spike of radioactivity around the plant that made the leakage categorically worse than in had been, with radiation levels measured at one point as high as 400 millisieverts an hour. Even 7 minutes of exposure at that level will reach the maximum annual dose that a worker at an American nuclear plant is allowed. And exposure for 75 minutes would likely lead to acute radiation sickness.
The extent of the public health risk depends on how long such elevated levels persist — they may have declined after the fire at No. 4 reactor was extinguished — as well as how far and fast the radioactive materials spread, and whether the limited evacuation plan announced by the government proves sufficient.
The succession of problems at Daiichi was initially difficult to interpret — with confusion compounded by incomplete and inconsistent information provided by government officials and executives of the plant’s operator, Tokyo Electric Power.
That fourth reactor had been turned off and was under refurbishment for months before the earthquake and tsunami hit the plant on Friday. But the plant contains spent fuel rods that were removed from the reactor, and experts guessed that the pool containing those rods had run dry, allowing the rods to overheat and catch fire. That is almost as dangerous as the fuel in working reactors melting down, because the spent fuel can also spew radioactivity into the atmosphere.
March 13, 2011 at 8:25 pm By Roz Potter
Via Nikkei.com Link
TOKYO (Kyodo)–A hydrogen explosion occurred Monday morning at the quake-hit Fukushima No. 1 nuclear power plant’s troubled No. 3 reactor, the government’s nuclear safety agency said.
The 11:01 a.m. incident came after a hydrogen explosion hit the No. 1 reactor at the same plant Saturday, and prompted the Nuclear and Industrial Safety Agency to urge residents within a 20-kilometer radius to take shelter inside buildings.
It also followed a report by Tokyo Electric Power Co., the plant’s operator, to the government earlier in the day that the radiation level at the plant had again exceeded the legal limit and pressure in the container of the No. 3 reactor had increased.
Millions are without power, water, food, sanitation or adequate shelter. The latter is what is needed most in a release of radioactive particles.
March 13, 2011 at 5:22 pm By Roz Potter
This group of scientists is more concerned than other sources posted earlier today.
Officials from Tokyo Electric reported that after multiple cooling system failures, the water level in the Unit 3 reactor vessel dropped 3 meters (nearly 10 feet), uncovering approximately 90 percent of the fuel in the reactor core. Authorities were able to inject cooling water with a fire pump after reducing the containment pressure by a controlled venting of radioactive gas. As they did with Unit 1, they began pumping sea water into Unit 3, which is highly corrosive and may preclude any future use of the reactor even if a crisis is averted.
However, Tokyo Electric has reported that the water level in the Unit 3 reactor still remains more than 2 meters (6 feet) below the top of the fuel, exposing about half the fuel to air, and they believe that water may be leaking from the reactor vessel. When the fuel is exposed to air it eventually overheats and suffers damage. It is likely that the fuel has experienced significant damage at this point, and the authorities have said they are proceeding on this assumption.
One particular concern with Unit 3 is the presence of mixed-oxide (MOX) fuel in the core. MOX is a mixture of plutonium and uranium oxides. In September 2010, 32 fuel assemblies containing MOX fuel were loaded into this reactor. This is about 6% of the core.
To read the full article Link
March 13, 2011 at 2:03 pm By Roz Potter
The U.S. Nuclear Regulatory Commission, the NRC, states today that fallout risk is “unlikely” to the U.S. due to the thousands of miles separating our country from Japan. Link
Scientists in Washington state are monitoring fallout levels. They see no reason for concern in the U.S. or Canada, but have concern for areas close to radiation source(s). Link
For those interested in detailed explanations and graphics of the situation at Japan’s nuclear reactors, see “Battle to Stabilize Earthquake Reactors” Link, an article from World Nuclear News.
It’s possible the jet stream could bring some highly diluted radioactive particles to the Americas. This will present no more radioactivity risk than everyday exposure. We have yet to learn if the meltdown(s) have resulted in breaches of the nuclear reactor container vessels, and if so, what type. That information could change the risk assessment.
Some radioactive elements such as iodine have a half life of 8 days. That means 50% will degrade in 8 days, another 50% in another 8 days, etc. (correction 3 14 11). Others, such as strontium, cesium and uranium remain radioactive for up to thousands of years.
March 13, 2011 at 1:35 pm By Roz Potter
There is consensus that at least one nuclear reactor has had a “meltdown”, without explanation as to the extent. There are conflicting reports on the number of reactors involved. Those within the affected area in Japan are urged to stay indoors, place a wet cloth over the mouth and nose, and close doors and windows.
If a core meltdown were to occur in the U.S., additional precautions would be advisable. These include: changing clothes and showering/shampooing or wiping down immediately upon coming indoors; turning off any heating or air conditioning systems; sealing vents to exhaust systems, bringing all pets indoors, avoiding activities that raise dust such as vaccuming; not consuming food that has been exposed in fields including animals and the milk of exposed animals, or water from open storage containers. An iodine preparation is often prescribed to prevent thyroid cancer but there are many other health effects from radiation. More on this topic later.
According to an NYT article, meltdowns have occurred at two nuclear reactors, and three more are at risk. Link
Japan’s top government official, Yukio Edano, said Sunday that one meltdown had occurred Unit 1 at Fukushima) and another ( unit 3 at Fukushima) is possible. Link
For a critical look at the nuclear industry in Japan, see the Guardian’s story here
Greenpeace weighs in on the nuclear disaster and states that there will be health impacts, “more or less long term”. Link
For before and after scenes of Japanese communities hit by the earthquake and tsunami, see the astonishing before and after photo gallery provided by the NY Times here . Use your cursor to move the center vertical bar to the right or left to view the entire scene.
Please give what you can to help those affected by this triple disaster. It’s most important that each of us takes this opportunity to add significantly to our own preparedness efforts.