March 21, 2011
power plants in Japan after the March 11 , 2011 earthquakes could become
a major nuclear disaster.
March 26, 2011 - Day 16 of Disaster
msnbc.com news services
updated 3/26/2011 4:24:06 AM ET 2011-03-26T08:24:06
TOKYO — Radioactivity levels are soaring in seawater near the crippled Fukushima Daiichi plant, Japan's nuclear safety agency said on Saturday, two weeks after the nuclear power plant was hit by a massive earthquake and tsunami.
Even as engineers tried to pump puddles of radioactive water from the power plant 150 miles north of Tokyo, the nuclear safety agency said tests on Friday showed radioactive iodine had spiked 1,250 times higher than normal in the seawater just offshore the plant.
A senior official from Japan's Nuclear and Industrial Safety Agency, Hidehiko Nishiyama, said the contamination posed little risk to aquatic life.
"Ocean currents will disperse radiation particles and so it will be very diluted by the time it gets consumed by fish and seaweed," he said.
Despite that reassurance, the disclosure may well heighten international concern over Japanese seafood exports. Several countries have already banned milk and produce from areas around the Fukushima Daiichi plant, while others have been monitoring Japanese seafood.
Meanwhile, U.S. naval barges loaded with freshwater sped toward the overheated nuclear plant to help workers remove dangerously contaminated water from the facility.
The switch to cooling reactors with freshwater was necessary because of fears salt and other contaminants in seawater were clogging up pipes and coating the surface of reactor vessels and fuel rods, hampering the cooling process, NISA said.
Defense Minister Yoshimi Kitazawa said late Friday that the U.S. government had made "an extremely urgent" request to switch to freshwater. He said the U.S. military was sending water to nearby Onahama Bay and would begin water injections early next week.
The Pacific Command confirmed Saturday that barges loaded with freshwater were dispatched to Fukushima.
Nuclear power concerns
Radioactive water was found in buildings housing three of the six reactors at the crippled plant. On Thursday, three workers sustained burns at reactor No. 3 after being exposed to radiation levels 10,000 times higher than usually found in a reactor.
The crisis at the nuclear plant has overshadowed the massive relief and recovery effort from the magnitude 9.0 quake and the huge tsunami it triggered on March 11 that left more than 27,500 people dead or missing in northeast Japan.
Despite such a shocking toll, much attention since the disaster has been on the possibility of a catastrophic meltdown at Fukushima.
With elevated radiation levels around the plant triggering fears across the nation, storage of the contaminated water has to be handled carefully.
"We are working out ways of safely bailing out the water so that it does not get out into the environment, and we are making preparations," Nishiyama said.
He initially said the high radiation reading meant there could be damage to the reactor, but he later said it could be from venting operations to release pressure or water leakage from pipes or valves.
"There is no data suggesting a crack," he said.
Nuclear watchdog the International Atomic Energy Agency (IAEA) said on Friday there had not been much change in the crisis over the previous 24 hours.
"Some positive trends are continuing but there remain areas of uncertainty that are of serious concern," agency official Graham Andrew said in Vienna, adding the high radiation could be coming from steam.
On Friday, Nishiyama chided plant operator Tokyo Electric Power Co (TEPCO) for not following safety procedures inside the turbine building. Local media also criticized TEPCO, which has a poor safety record.
"The people on the spot have a strong sense of mission and may be trying to rush," the Nikkei business paper said. "But if the work is done hastily, it puts lives at risk and in the end, will delay the repairs. This kind of accident ought to have been avoidable by proceeding with the work cautiously."
UPDATE AS OF 7:00 P.M. EDT, MARCH 25:
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.
Lighting has been restored in the control rooms of reactors 1 through 4 at the plant, which lost electric power after the March 11 earthquake and tsunami, the Japan Atomic Industrial Forum said. With offsite electric service connected to all the units, workers are attempting to connect plant safety equipment. Some pumps and other equipment that were damaged in the earthquake and tsunami must be repaired or replaced.
Water spraying to maintain cooling of used uranium fuel rods in the reactor 3 used fuel storage pool was suspended because of high radiation levels near that building, but spraying into the reactor 1 and 4 storage pools continued.
Reactors 5 and 6 are safely shutdown and are being cooled with pumps using offsite electricity.
Radiation dose rates at the Fukushima Daiichi site boundary continue to range from 1 millirem to 3 millirem per hour.
March 25, 2011 - Day 15 of Disaster
Reactor 3 may have leaked. This news came as the Japanese government recommended all persons liviing up to 18 miles from the site be evacuated. This is up from the original 12 miles recommended earlier and far short of the US government's recommendation to it civilians to evacuate within 50 miles.
Confusing reports were issued about workers being "burned" by the radioactive water in the areas where they were laying cables. The burns by the radiation workers at Fukushima were reported to be 170 mSv. This is 17,000 mR or 17 RADs. In the USA and Japan as well, we allow our workers to have 500 mSv or 50 RADs to their feet as normal maximum industrial exposure. No burns would be seen at 170 mSv. Either the 170 mSv is wrong or they were not burned and this would not be an issue.
March 24, 2011 - Day 14 of Disaster
of Fukushima Daiichi nuclear power station as of 21:00, March 24, 2011
March 23, 2011
has issued warning about using tap water for infants due to I-131 levels
being double what is considered safe.
following interesting chart is by Randal Munroe at Reed Research Reactor
March 22, 2011
UPDATE AS OF 8:00 P.M. EDT, MONDAY, MARCH 21:
NEI has added a new graphic to its website: Emergency Preparedness: Protecting the Public and Environment.
UPDATE AS OF 6:30 P.M. EDT, MONDAY, MARCH 21:
Japan’s NHK broadcasting network reported that Tokyo Electric Power Co. confirmed that the March 11 earthquake and tsunami were beyond the Fukushima Daiichi plant’s design standards.
TEPCO believes the tsunami that inundated the Fukushima Daiichi site was 14 meters high, the network said. The design basis tsunami for the site was 5.7 meters, and the reactors and backup power sources were located 10 to 13 meters above sea level. The company reported that the maximum earthquake for which the Fukushima Daiichi plants were designed was magnitude 8. The quake that struck March 11 was magnitude 9.
Smoke seen from Fukushima Daiichi reactor 3 on Monday subsided after about two hours. Water pressure and levels at the reactor were unchanged through the episode, as were radiation levels, the company said.
The site was temporarily cleared of workers after smoke rose from at the secondary containment buildings that house reactors 2 and 3. The Nuclear and Industrial Safety Agency said the smoke from reactor 2 caused radiation levels downwind to rise for about three and a half hours.
TEPCO continues work to reconnect external power to all six reactors. Connections were made to the distribution line at reactor 1 and 2, and components and circuits at those reactors are being checked. Similar power connections have been made to reactors 5 and 6 and a diesel generator is providing power to a cooling pump for the used fuel pools. Power cable is being laid to reactor 4, and power is expected to be restored to reactors 3 and 4 by Tuesday.
March 21, 2011
March 21, 2011: The left is background in Sendai, Japan
... the right is Moore, SC
The following pictures show the normal
radiation levels in and airplane:
Originally published Monday, March 21, 2011 at 7:04 AM
NRC: Containment at 3 reactors in Japan intact
The Nuclear Regulatory Commission staff says containment at three reactors at Japan's crippled nuclear complex is currently intact and the situation at the plant appears to be stabilizing.
The NRC met to get an update from staff on the ongoing crisis in Japan and devise a plan to meet President Barack Obama's call for a comprehensive safety review at the 104 U.S. nuclear reactors.
Bill Borchardt, the commission's executive director for operations, says that units 1, 2 and 3 at the Fukushima Dai-ichi plant have some core damage but that containment for those three reactors is not currently breached.
He stated that the situation at the plant appear to be on the verge of stabilizing.
THE NUCLEAR COMMUNICATIONS NETWORK
Japan Update / Brief No. 75 /
Figures Released On Fukushima-Daiichi Seismic Design Reference Values 20 Mar (NucNet): The maximum ground acceleration near unit 3 of the
Fukushima-Daiichi nuclear plant from the earthquake that struck northern Japan on 11 March 2011 was 507 gal – or 507 centimetres per second squared
– which is above the plant’s design reference values of 449 gal, the JapanAtomic Industrial Forum (JAIF) said today.
It was also announced that the University of Tokyo has re-evaluated the maximum height of the tsunami wave and it had a peak height of at least 23 metres when it hit Miyagi and Fukushima prefectures. The plant design reference value was 10 metres.
Meanwhile, external power is available onsite at the plant and teams from the Tokyo fire service and national Self-Defence Force are continuing to
pump seawater into the reactor pressure vessels (RPV) and primary containment vessels (PCV) at units 1, 2 and 3 in an effort to cool the nuclear fuel.
The International Atomic Energy Agency said workers were continuing efforts to restore plant systems at units 1, 2 and 3.
At unit 2, external power has been established to the control room meaning essential surveillance and control systems are again operational, Japan’s
Nuclear and Industrial Safety Agency (NISA) said.
NISA said workers were preparing to connect an external power supply to the residual heat removal systems of unit 2 and then unit 3. If the systems
have not been damaged, this will allow cooling and feeding of the reactors and the spent fuel pools (SFPs).
Seawater spraying into the SFP at unit 3 has begun and while the pressure in the PCV went up early today, it was not sufficiently high to justify
venting. The local dose rate close to this unit is decreasing At unit 4, where there is no fuel in the reactor, seawater spraying of the
SFP started today at 09:40 Japan time (01:40 central European time). An external power supply connection is being prepared, NISA said.
At units 5 and 6, diesel generators were repaired yesterday and there is now enough power available to each unit for the residual heat removal
system pumps. NISA said the temperature has fallen in both SFPs and the units were now in cold shutdown. Workers were today preparing to connect an
external power supply to both these units.
Cold shutdown means the reactors are in a safe mode, with cooling systems stable and under control, and with low temperature and pressure within the
Air Sample Analysis
Plant operator Tokyo Electric Power Company (Tepco) said today it made the first spectral analysis of air samples taken on the Fukushima-Daiichi site
at noon on Saturday local time and found volatile iodine and particulate caesium isotopes as follows:
Iodine-131: 5900 becquerel per cubic metre (Bq/cubicm), above the limit of 1000 Bq/cubicm;
Iodine-132: 220 Bq/cubicm, below the limit of 70,000 Bq/cubicm;
Cesium-134: 22 Bq/cubicm, below the limit of 2000 Bq/cubicm;
Cesium-137: 24 Bq/cubicm, below the limit of 3000 Bq/cubicm.
The limits are for air being breathed by workers under surveillance, but Tepco said workers were wearing charcoal masks and no internal
contamination is expected.
Environmental Radiation Monitoring
The Ministry of Education, Culture, Sports, Science and Technology (MEXT) has published updated data from its surveillance network of automatic
measurement posts (MPs) at a distance of more than 20 kilometres from the plant site. Inside the 20 km zone, Tepco is responsible for the network,
but under NISA’s surveillance.
The downward trend of all measurements has continued since yesterday.
Today (Sunday), the highest dose rates were measured at the north-eastern Fukushima Mountains (summit 864 m, 30 km from the plant site), with values
between 45 and 110 microsieverts per hour (microSv/hr) at 12:00 noon Japan time today in comparison with 60 to 170 microSv/hr on Thursday.
In the valleys, where most people live, the readings range from 1 to 6 microSv/hr in a distance of 35 to 60 km from the plant site. This is 25
percent less than on Thursday.
All these readings refer to an area north-west of the plant. This was the direction in which prevailing winds were blowing during the first days of
the accident when the main releases occurred.
In the Tokyo area, the dose rate stayed very low at 0.05 microSv/hr.
Yesterday the government’s chief cabinet secretary Yukio Edano said radiation exceeding the government-set radiation level was detected in
sampled milk in Fukushima Prefecture and in six samples of spinach in neighbouring Ibaraki Prefecture.
March 19, 2011
Chidren's Cartoon About Acident: OMG
Six workers at Japan's Fukushima Daiichi nuclear power plant have been exposed to radiation beyond the previous limit for an emergency operation, Tokyo Electric Power Co. said Saturday.
Kyodo News reported the employees, whose job titles were not known, were continuing to work despite having been exposed to more than 100 milli-Sieverts of radiation. The Health, Labor and Welfare Ministry raised the exposure limit to 250 milli-Sieverts for the current nuclear crisis. This is 25 REMS. The power company said the workers have shown no abnormal signs from exposure.
Radiation levels shoot up in Tokyo, vicinity
TOKYO, March 15, Kyodo
Radiation levels shot up in Tokyo and its vicinity Tuesday following the nuclear accident at the Fukushima No. 1 nuclear power plant in northeastern Japan that was triggered by last week's massive earthquake and subsequent tsunami, local governments said.
But those levels did not pose immediate danger to human health, the Ministry of Education, Culture, Sports, Science and Technology said.
In Tokyo, small amounts of radioactive substances, such as iodine and cesium, were detected, the metropolitan government said.
In Ibaraki Prefecture, adjacent to Fukushima Prefecture where the troubled Fukushima No. 1 nuclear power plant is located, the amount of radiation at one stage reached 5 microsievert per hour, 100 times higher than usual, the Ibaraki prefectural government said.
In Kanagawa Prefecture, the radiation level shot up 10 times higher than usual.
In Saitama, capital of Saitama Prefecture, the amount of radiation reached 1,222 nanosievert per hour -- a figure about 40 times higher than usual.
In Ichihara, Chiba Prefecture, the amount of radiation showed a two- to four-fold increase, the Chiba prefectural government said.
The amount of radiation rose to 1.318 micro sievert per hour -- a figure 33 times bigger than usual -- in Tochigi Prefecture's capital of Utsunomiya, the Tochigi prefectural government said.
The science ministry said it had asked prefectural governments to observe radiation levels as frequently as possible.
Meanwhile, Chief Cabinet Secretary Yukio Edano said the radiation level reached 400 millisievert per hour near the No. 3 reactor at the Fukushima No. 1 plant Tuesday morning. The amount is 400 times higher than the allowable limit for citizens in a year.
On Monday, the radiation level near the No. 3 reactor peaked at 3,130 microsievert or about 3 millisievert per hour.
Steam containing radioactive substances was released from the Fukushima No. 1 nuclear power plant as part of efforts to reduce pressures within the reactor container there.
Northerly winds brought radioactive substances from Fukushima Prefecture to Tokyo and its vicinity, nuclear experts said.
FUKUSHIMA, Japan (AP) -- Emergency teams
racing to cool dangerously overheated nuclear fuel scrambled Saturday
to connect Japan's crippled reactors to a new power line, as a safety
official suggested faulty planning at the complex helped trigger the crisis.
March 18, 2011
Mar 18, 10:18 AM EDT
APNewsBreak: Source: minuscule fallout
Japan Earthquake Update (18 March 2011, 06:10 UTC)
Temperature of Spent Fuel Pools at Fukushima Daiichi Nuclear Power Plant - UPDATED
Spent fuel removed from a nuclear reactor is highly radioactive and generates intense heat. Nuclear plant operators typically store this material in pools of water that cool the fuel and shield the radioactivity. Water in a spent fuel pool is continuously cooled to remove heat produced by spent fuel assemblies. According to IAEA experts, a typical spent fuel pool temperature is kept below 25 °C under normal operating conditions. The temperature of a spent fuel pool is maintained by constant cooling, which requires a constant power source.
Given the intense heat and radiation that spent fuel assemblies can generate, spent fuel pools must be constantly checked for water level and temperature. If fuel is no longer covered by water or temperatures reach a boiling point, fuel can become exposed and create a risk of radioactive release. The concern about the spent fuel pools at Fukushima Daiichi is that sources of power to cool the pools have been compromised.
Concern about spent fuel storage conditions has led Japanese officials to drop and spray water from helicopters and trucks onto Unit 3 at Fukushima Daiichi nuclear power plant (See earlier update).
Japan's Nuclear and Industrial Safety Agency has reported increasing temperatures in the spent fuel ponds at Units 5 and 6 since 14 March. An emergency diesel generator at Unit 6 is now powering water injection into the ponds at those Units, according to NISA.
The IAEA can confirm the following new information regarding the temperatures of the spent nuclear fuel pools at Units 4, 5 and 6 at Fukushima Daiichi nuclear power plant:
The IAEA is continuing to seek further information about the water levels, temperature and condition of all spent fuel pool facilities at the Fukushima Daiichi nuclear power plant.
Radiation detectors at Dallas-Fort Worth and Chicago O’Hare airports were triggered when passengers from flights that started in Tokyo passed through customs, the New York Post reported.
Tests at Dallas-Fort Worth indicated low radiation levels in travelers’ luggage and in the aircraft’s cabin filtration system; no passengers were quarantined, the newspaper said.
Dose levels by Isotope
This figure shows the location of the spent fuel ponds:
The problem, as is explained in this updated fact sheet by the NEI, is that as these ponds heat, their deep covering of water (which acts as a radiation shield and a cooling mechanism), starts to evaporate. If they reach boiling point, because of lack of operational maintenance systems, the evaporation rate will accelerate. If exposed, the there is a potential for these old fuel rods and their zirconium cladding to melt, and radiation levels will rise considerably. The heat generated in spent fuel depends on a number of parameters, including: (1) level of build-up of fission products (burn-up) and (2) length of time after having been taken out of the reactor.
The spent fuel pool temperature has been rising gradually since last Friday due to the loss of cooling pump (presumably no power source). As we know from previous updates, the side of the Reactor 4 building has been lost (it’s the left-most of the 4 buildings in the following image):
The Unit 4 reactor was already shut off for periodic maintenance when the earthquake struck. IF the fire was caused by hydrogen, its only plausible source would be spent fuel degrading in steam. Under this scenario, initial inventory was probably reduced by sloshing during the earthquake, and heat generation and resulting evaporation/boiling would thereafter be more than double that in other pools due to it containing freshly off loaded fuel. Temperature indications in the absence of water would be that of the mixture of steam and air in the location of the thermowell.
Nothing can be confirmed at this stage. As has been the case throughout this crisis, information is hard to come by and must be pieced together.
Are the spent fuel in the pools in Units 3 and 4 are now uncovered? TEPCO claims that NRC Chief Jaczko was wrong in claiming this, that the spent fuel pools in both Units 3 and 4 need some refilling but are NOT dry. (The Japanese authorities are apparently saying they’ve seen water still in the Unit 4 pool.) The big concern here is that unlike the releases from damaged fuel in the reactor cores of Units 1, 2, and 3, which were largely filtered by scrubbing in the containment suppression pools (wetwell torus), releases of volatile fission products (e.g., cesium and iodine) from these spent fuel pools have direct pathways to the environment, if they remain dry for an extended period.
Efforts to deliver water to these pools have proven to be very difficult, and fuel damage may be occurring.
If they are exposed, then the use of the evaporation of salt water as a heat sink over periods of more than a few days is not viable because the quantities of salt deposited as the water evaporates becomes large in volume and plugs the flow paths through the fuel, degrading heat removal. Everything that is cooled becomes a heat sink to condense anything volatilised. Unfortunately, a fresh water supply seems difficult to come by.
One option is to bring fresh water by helicopter, but the amounts needed imply a large number of flights and gamma radiation levels are high above the pools making overflights hazardous. NHK has reported a number of successful water dumps using helicopters today. If radiation levels on the ground increase further, personnel access will become more challenging. Additional spent fuel is stored in pools in Units 5 and 6 and in a large centralized storage pool. A key issue is how to continue to make up water to these pools in the longer term, particularly if site access becomes more difficult.
It was announced at a press conference that a total of 11 specially-equipped vehicles will be used to spray water on the crippled reactors at Fukushima-1 after an access path is cleared using bulldozers. The big advantages of fire trucks over helicopters is that their water cannons can be better aimed, from the side rather than the top, and their operation is continuous rather than in batches so they can deliver vastly more water. It is clearly an appealing option. An additional 130 personnel have also been moved back on site to help with work.
Some additional key information from NEI:
Crews began aerial water spraying operations from helicopters to cool reactor 3 at Fukushima Daiichi shortly before 9 p.m. EDT on Wednesday, March 16. The operation was planned for the previous day, but was postponed because of high radiation levels at the plant. News sources said temperatures at reactor 3 were rising. Each helicopter is capable of releasing 7.5 tons of water.
Spokesmen for TEPCO and Japan’s regulatory agency, Nuclear and Industry Safety Agency, on March 17 Japan time refuted reports that there was a complete loss of cooling water in the used fuel pool at Fukushima Daiichi reactor 4.
The spokesmen said the situation at reactor 4 has changed little during the day today and water remained in the fuel pool. However, both officials said that the reactor had not been inspected in recent hours.
“We can’t get inside to check, but we’ve been carefully watching the building’s environs, and there has not been any particular problem,” said TEPCO spokesman Hajime Motojuku.
At about 7 p.m. EDT, NISA spokesman Takumi Koyamada said the temperature reading from the used fuel pool on Wednesday was 84 degrees Celsius and that no change had been reported since then. Typically, used uranium fuel rods are stored in deep water pools at temperatures of about 30 degrees Celsius.
Recent radiation levels measured at the boundary of the Fukushima Daiichi plant have been dropping steadily over the past 12 hours, Japan’s Nuclear and Industrial Safety Agency said on Wednesday night (U.S. time).
At 4 a.m. EDT on Wednesday, a radiation level of 75 millirem per hour was recorded at the plant’s main gate. At 4 p.m. EDT, the reading at one plant site gate was 34 millirem per hour. By comparison, the Nuclear Regulatory Commission’s annual radiation dose limit for the public is 100 millirem. Radiation readings are being taken every 30 minutes.
Japan’s Chief Cabinet Secretary, Yukio Edano, said earlier today a radiation level of 33 millirem per hour was measured about 20 kilometers from the Fukushima Daiichi plant earlier this morning. He said that level does not pose an immediate health risk.
Edano said that TEPCO has resumed efforts to spray water into the used fuel pool at the damaged reactor 4.
TEPCO also continues efforts to restore offsite power to the plant, with up to 40 workers seeking to restore electricity to essential plant systems by Thursday morning, March 17.
Press Release (Mar 16,2011)
Below is the status of TEPCO's major facilities that suffered
[Nuclear Power Station]
*The national government has instructed to evacuate for
those local residents within 20km radius of the site periphery and to
*Since the value of radioactive materials (iodine, etc)
at the site (outside) measured by monitoring car exceeded the ordinary
* Unit 1
At approximately 11:01 am, March 14th, an explosion followed
by white smoke occurred near Unit 3. 4 TEPCO employees and 3 workers from
At approximately 5:45 am, a TEPCO employee discovered
a fire at the northwest corner of the Nuclear Reactor Building. TEPCO
Fukushima Daini Nuclear Power Station:
*As the radiation dose at the site boundary exceeded the
limitation, it was determined that a specific incident stipulated in article
*Reactor cooling function was restored and cooling of
rectors was conducted. As a result, all reactors achieved cold shutdown:
* (Unit 1)
* (Unit 4)
*1:emergency water system in which cooling water (pure
water) circulates which exchanged the heat with sea water in order to
cool down bearing
Kashiwazaki Kariwa Nuclear Power Station:
March 16 : The "Fukushima Fifty"
Are Being Sent Back In
Surgeon General to west
coast: "Hey, might be worth stocking up on iodide"
"Regardless of what the Surgeon General says about taking iodine tablets, the threat to the USA from radioactive iodine is extremely low. Taking these tablets should be done only when needed due to thyroid issues as well as other issues related to potassium. It is good to know we have knowledgeable officials in Washington" - Steve Fowler
Radiation Levels at Fukushima
Boiling Water Reactor versus a Pressurized Water Reactor: Fukushima is a BWR like 1/3 of the ones in the USA.
A BWR boils water to make steam which then is sent to the turbine to turn the generator.
A PWR uses a heat exchanger inside the containment vessel – the primary water goes through the heat exchanger which then heats up clean water which then is sent to the turbine. This causes the PWR to be a little less efficient ~1 to 2 percent. The advantage is only a small portion of the plant is radioactive.
About 2/3 of the US plants are PWRs while the rest are BWRs. Since less of the plant has radiactive water in it, it may be considered a safer form of generation.
Before we throw Nuclear power out with
the bathwater, you need to know a FACTOID About Coal Powered Plants:
Trace quantities of uranium in coal range from less than 1 part per million (ppm) in some samples to around 10 ppm in others. Generally, the amount of thorium contained in coal is about 2.5 times greater than the amount of uranium. For a large number of coal samples, according to Environmental Protection Agency figures released in 1984, average values of uranium and thorium content have been determined to be 1.3 ppm and 3.2 ppm, respectively. Using these values along with reported consumption and projected consumption of coal by utilities provides a means of calculating the amounts of potentially recoverable breedable and fissionable elements (see sidebar). The concentration of fissionable uranium-235 (the current fuel for nuclear power plants) has been established to be 0.71% of uranium content.
Based on the predicted combustion of 2516 million tons of coal in the United States and 12,580 million tons worldwide during the year 2040, cumulative releases for the 100 years of coal combustion following 1937 are predicted to be:
U.S. release (from combustion of 111,716 million tons):
By the way, much of this ash with the Uramium and thorium in it is sold to concrete suppliers. You may be standing on some.
March 15, 2011: What creats the hydrogen which exploded in the now 3 buildings:
Two ways hydrogen can be produced in a reactor one way happens all the time and that is Radiolysis water is broke down into hydrogen and oxygen when introduced through a high radiation field. We compensate for this reaction with a system called the recombiner which recombines the gases.
But production of hydrogen in large amounts is when the zirconium (used as fuel cladding) is heated to 1000 C and above this creates Zirconium oxide and hydrogen, as temperature goes up more of this reaction will occur.
Normal operating temperature of a boiling water reactor is ~ 280 C so in order for this reaction to occur there was no water on the fuel.
UPDATE AS OF 10:25 P.M. EDT, MONDAY, MARCH 14:
Yukio Edano, Japan’s Chief Cabinet Secretary, during a live press conference at 10 p.m. EDT, said there is a fire at Fukushima Daiichi 4 that is accompanied by high levels of radiation between Units 3 and 4 at the site. The fire began burning at Unit 4 at around 6 a.m. Japan time on March 14 and is still burning. Fire fighters are responding to the fire. The reactor does not have fuel in the reactor, but there is spent fuel in the reactor (pool) and Edano said that he assumes radioactive substances are being released. “The substances are coming out from the No. 4 reactor and we are making the utmost effort to put out the first and also cool down the No. 4 reactor (pool).”
Edano said that a blast was heard this morning at Unit 2 at about 6:30 a.m. A hole was observed in the number 2 reactor and he said there is very little possibility that an explosion will occur at Unit 2.
“The part of the suppression chamber seems to have caused the blast,” Edano said. A small amount of radioactive substance seems to have been released to the outside.
TEPCO workers continue to pump sea water at 1, 2 and 3 reactors. “The biggest problem is how to maintain the cooling and how to contain the fire at No. 4.” At 10:22 a.m. Japan time, the radiation level between units 2 and 3 were as high as 40 rem per hour. “We are talking about levels that can impact human health.” Edano said.
Of the 800 staff that remained at the power plant, all but 50 who are directly involved in pumping water into the reactor have been evacuated.
Nuclear Energy Institute Update March 14, 2011, 1:30 p.m. EDT
Unit 2 at the Fukushima Daiichi nuclear power plant lost a significant amount of reactor coolant for a second time on Monday. Some of the uranium fuel rods
were uncovered for a period of time. A malfunctioning safety relief valve at the plant caused an increase in reactor pressure and hindered injection of coolant
back into the reactor. The cause of the relief valve failure is under investigation. The Japanese government has distributed 230,000 units of potassium iodine to
evacuation centers in the area surrounding the Fukushima Daiichi and Fukushima Daini stations, according to officials. Ingestion of potassium iodine can help
prevent the accumulation of radioactive iodine in the thyroid. At the Fukushima Daini site, all units have off-site power, and water levels in all units are stable. Plant operators at Daini Unit 1
were able to restore a residual heat removal system, which is now being used to cool the reactor. Work is in progress to achieve a cold shutdown. Workers at
Daini Units 2 and 4 are working to restore residual heat removal systems. Unit 3 is in a safe, cold shutdown. Radiation dose rate measurements observed at four locations around the
Daini plant´s perimeter over a 16-hour period on Sunday were all normal.
Press Release (Mar 14,2011)
As of 1:30 pm, 4 TEPCO employees and 3 workers from other companies have
sustained injuries (all of them are conscious). 3 ambulances are in
As of 0:30 pm, the measured value of radiation dose near MP6 was 4ìSv/h. The increase of the radiation dose cannot be confirmed at this time.
As of 0:30 pm, the measured value of radiation dose at the monitoring
post in Fukushima Daini Power Station located approximately 10 km south
In light of the incidents that have occurred at Units 1 and 3, we are
considering applying prevention measures to the wall of the reactor
TEPCO continues to take all measures to restore the safety and security of the site and are monitoring the site's immediate surroundings.
March 14, 2011: 2nd Explosion at Fukushima: F
Fuel Rods were briefly exposed.
March 13, 2011: TEPCO posted status as of 1600 All 6 units of Fukushima Daiichi Nuclear Power Station have been shut down.
1. March 12, 2011 9 a.m: The Fukushima plants are fully shutdown, rods normally inserted. They are overheating on decay heat from delayed spontaneous fission (not neutron induced). IIRC decay heat represents ~7% reactor power at shutdown and decays at a rate determined by the power history. The authorities have evalcuated a wide area and are beginning to issue potassium iodide tablets to prevent thyroid damage: http://afludiary.blogspot.com/2011/03/iaea-update-on-fukushima-plant.html
2.March 12, 2011 11 a.m.: They are pumping sea water and boric acid into the Unit 1 reactor. We believe the hydrogen explosion disabled all of the electrical and pneumatic controls for the reactor core in the containment. This is a real ad hoc last-ditch procedure to prevent decay heat from melting more of the fuel rods.
3. March 12, 2011 3:30 pm.m: There has been a confirmed fatality.
A seriously injured worker who had been trapped in the crane operating
console of the exhaust stack was transported to the ground at 5:13pm and
confirmed dead at 5:17pm.
4. March 12, 2011 4 p.m.: IAEA Youtube Statement: http://www.youtube.com/watch?v=g82a36LWtcU