In This Section
UPDATE AS OF 11:30 A.M. EDT, THURSDAY, MARCH 31:
A minuscule amount of radioactive iodine was detected in milk in Spokane, Wash., the U.S. Environmental Protection Agency reported.
The agency said the level detected—0.8 picocuries per liter—is more than 5,000 times lower than the level that would prompt any action by the U.S. Food and Drug Administration to pull milk from grocery stores. “These types of findings are to be expected in the coming days and are far below levels of public health concern, including for infants and children,” the EPA said.
The EPA has increased its nationwide monitoring of milk, rain water and drinking water (see the agency’s website for information on radiation air monitoring).
Tokyo Electric Power Co. is increasing its efforts to remove radioactive water that has pooled inside concrete vaults that house pipes near the reactors at the Fukushima Daiichi nuclear plant. Maintaining cooling water flow to the reactors and used nuclear fuel storage pools and containing and removing the contaminated water continue to be priorities for workers at the site.
Contaminated water was found in the basements of the turbine buildings at reactors 1-4 and in the concrete vaults outside the buildings. Workers finished pumping water from the reactor 3 turbine building and are removing water from the reactor 1 tunnel into a storage tank. Today, TEPCO has been pumping contaminated water from the reactor 2 turbine building into a storage tank.
Freshwater injection continues to cool reactors 1, 2, and 3. The company also is spraying cooling water into the used nuclear fuel storage pools at reactors 1-4. (For information on how spent fuel pools work, see NEI’s video.)
All reactors at the Fukushima Daini site remain in safe condition. Smoke seen at reactor 1 at the Daini site on Wednesday resulted from a short circuit in a sump pump at the reactor. The smoke stopped after workers at the facility opened the power supply to the breaker for the pump. The cause of the short circuit is being investigated.
UPDATE AS OF 12 P.M. EDT, WEDNESDAY, MARCH 30:
Operators of nuclear power stations in Japan have been urged to ensure their facilities have emergency power sources.
Industry Minister Banri Kaieda Wednesday attributed the nuclear emergency in Japan to the loss of cooling systems at the Fukushima Daiichi nuclear power plant, the Japan Atomic Industry Forum reported. He told utility companies they should have mobile generators on hand to cool their nuclear reactors as an added safety measure.
Kaieda said the utilities should confirm the steps they have taken and conduct drills within a month or stop operating their nuclear facilities.
According to the NHK news service, many companies are introducing emergency power generators to their facilities. Some have conducted drills for cooling operations based on a situation in which emergency generators fail.
At the Fukushima Daiichi site, workers continued to inject fresh water into reactors 1, 2 and 3 to keep them cool, while at the same time dealing with water that has pooled in the basements of turbine buildings and in concrete trenches near the units. As available storage space in the reactors’ condensers is filled, Tokyo Electric Power Co. is looking to store the radioactive water in tanks that will be brought to the facility. TEPCO has switched to fresh water for spraying the spent fuel pools for reactors 1, 2, 3 and 4.
All the units at Daiichi are operating on off-site electric power and work continues to connect equipment. High radiation levels and wet equipment still hampers restoration of the plants’ original machinery.
The U.S. nuclear energy industry will learn important lessons from the Fukushima Daiichi accident and “identify additional steps we can and will take to further improve safety at our nuclear plants,” one of the industry’s leaders told a U.S. Senate committee today.
“U.S. nuclear power plants are safe. Still, we cannot be complacent about the accident at Fukushima,” said William Levis, president and chief operating officer at PSEG Power LLC, which operates three reactors in New Jersey and is part owner of two others in Pennsylvania. To read more, click here.
UPDATE AS OF 6:30 P.M. EDT, TUESDAY, MARCH 29:
Tokyo Electric Power Co. said that cooling water is being added to the spent storage fuel pools at reactors 2 and 3. Reactor 2 was using a temporary motor-driven pump and reactor 3 was using a truck to pump the freshwater into the fuel storage pools. The International Atomic Energy Agency (IAEA) said that plans are being made to begin pumping freshwater into the fuel storage pool at reactor 4 starting today.
IAEA said that 63 food samples taken March 24-29 in eight prefectures (Chiba, Fukushima, Gunma, Ibaraki, Miyagi, Niigata, Tochigi and Yamagata) were below regulatory limits set by the Japanese government for iodine-131, cesium-134 and cesium-137.
New analyses of seawater about 1,000 feet from the discharge point of reactors 1 through 4 show “a significant decrease” in radiation levels from March 26, IAEA said.
Readings for iodine-131 went from 2,000,000 picocuries (1 picocurie is one-trillionth of a curie) per liter on March 26 to 297,300 picocuries per liter on March 27. Readings for cesium-137 went from 324,324 picocuries per liter on March 26 to 51,351 picocuries per liter on March 27. IAEA said that radiation readings in seawater “will be quite variable in the near future depending on water discharge levels.”
Japan’s National Research Institute of Fishery Science has analyzed five fish samples from the port of Choshi in Chiba prefecture and found concentrations in the fish to be “far below any concern for fish consumption.” Four of five samples showed cesium-137 concentrations below the limit of detection. In the remaining sample, cesium-137 was found to be slightly above detectable levels.
IAEA said the situation was evolving, but that concentrations of radionuclides in seawater would soon drop to lower values by dilution and that the levels in marine food would most likely not reach levels above regulatory limits set for consumption.
In the United States, the U.S. Environmental Protection Agency’s daily data summary from its RadNet radiation air monitors across the United States show typical fluctuations in background radiation levels as of 8:30 A.M. EDT. “The levels detected are far below levels of concern,” EPA said.
UPDATE AS OF 4:30 P.M. EDT, TUESDAY, MARCH 29:
NEI has uploaded two videos to its YouTube channel. The first video discusses the lessons learned from Japan and the second video discusses the future of nuclear power. Both videos feature Maria Korsnick, Constellation Energy Nuclear Group’s chief nuclear officer.
UPDATE AS OF 3 P.M. EDT, TUESDAY, MARCH 29:
Plutonium found in five soil samples at the Fukushima Daiichi nuclear power plant complex originated from uranium fuel at the plant, Tokyo Electric Power Co. has determined. The level of radiation from the plutonium is not considered dangerous to human health.
The company on March 28 said that some of the plutonium—which is at a very low level—could have been the result of fallout from atomic weapons tests during the Cold War.
Fresh water is being injected into reactors 1, 2 and 3 to cool fuel in the reactors. Workers have switched from diesel fire pumps to temporary electric pumps to move water into the reactors. U.S. Navy barges filled with fresh water have arrived at the site with much-needed supplies of fresh water to pump into the reactors and used nuclear fuel storage pools.
TEPCO also continues to clean contaminated water from the basements of the turbine buildings at the three reactors. The water is being pumped into the main condenser for each reactor. Workers also are working to drain water remaining at unit 4.
As reported earlier, radioactive water has been found in concrete-enclosed channels that hold piping and cables outside of the reactor 1, 2, and 3 turbine buildings. TEPCO is assessing the best way to remove the water from these structures. None of the trenches empty directly into the sea near the Fukushima plant.
NEI’s Pietrangelo Briefs Senate Energy and Natural Resources Committee
Tony Pietrangelo, NEI senior vice president and chief nuclear officer, briefed members of the Senate Energy and Natural Resources Committee on events in Japan and steps U.S. companies are doing to ensure safety and emergency preparedness at nuclear energy facilities. To watch video of Pietrangelo’s briefing, click here and go to the 94-minute mark.
UPDATE AS OF 11:30 A.M. EDT, TUESDAY, MARCH 29:
NEI has posted a new fact sheet, “No Health Risk from Plutonium at Fukushima Daiichi.”
UPDATE AS OF 11 A.M. EDT, TUESDAY, MARCH 29:
Japan’s nuclear regulatory agency says Tokyo Electric Power Co. needs to balance injecting cooling water into the reactors at the Fukushima Daiichi nuclear power plant and preventing contaminated water from seeping out, the Japan Atomic Industrial Forum reported Tuesday.
On Monday, TEPCO reported radiation levels of more than 100 rem per hour on the surface of puddles in the reactor 2 turbine building and in a trench outside the building. TEPCO is using sandbags to keep the water confined to the trench, a concrete channel that does not connect to the ocean. The trenches at reactors 1 and 3 are also at risk of overflowing and measures are being taken to contain the water.
The Nuclear and Industrial Safety Agency is awaiting the results of new Science Ministry tests for radioactivity beyond 20-kilometers from Fukushima Daiichi and new samples from TEPCO of the plant grounds.
On Monday, TEPCO discovered minute levels of plutonium in the soil at five locations at the site. The plutonium measured is as little as was in the environment in Japan following nuclear weapons testing during the Cold War and poses no health risk to humans.
UPDATE AS OF 7 P.M. EDT, MONDAY, MARCH 28:
The International Atomic Energy Agency said that Japan’s Nuclear and Industrial Safety Agency is planning a meeting with Tokyo Electric Power Co. to determine the origin of contaminated water in the turbine buildings at the Fukushima Daiichi nuclear power plant.
Contaminated water from the basement floor of the reactor 1 turbine building is being pumped into its main condenser. At reactor 2 that process has not begun because the steam condenser is full, IAEA said. Pumping contaminated water is being considered at reactors 3 and 4.
Three workers who received radiation exposure from standing in contaminated water were released today from the National Institute of Radiological Sciences, where they had been under observation. The level of localized exposure received by two of the workers is between 200 to 300 rem, lower than the previous estimate of 200 to 600 rem, IAEA said.
Radiation Monitoring Continues
Results from ocean monitoring stations up to 18 miles off the shoreline from the Fukushima Daiichi plant showed levels of iodine-131 at most locations were below federal limits. IAEA said results from four monitoring stations on March 26 showed iodine-131 concentrations were between 162 and 486 picocuries (1 picocurie is one-trillionth of a curie) per liter. Cesium-137 concentrations ranged from below the level of detection up to 432 picocuries per liter.
IAEA said that it is still too early to draw conclusions for expected concentrations in marine food, because the situation can change rapidly.
The latest sampling shows that drinking water in Fukushima and Ibaraki prefectures remain below the Japanese limits for the ingestion of drinking water by infants. Iodine-131 was reported in food samples taken from March 26 to March 27 in six prefectures (Fukushima, Gunma, Ibaraki, Niigata, Tochigi and Yamagata) in vegetables, strawberries and watermelon.
The U.S. Environmental Protection Agency identified trace amounts of radioactive isotopes at its 12 RadNet air monitor locations across the nation. The levels are extremely low and are far below levels that would be a public health concern. EPA’s samples were captured by monitors in Alaska, Alabama, California, Hawaii, Idaho, Nevada and Washington state over the past week and sent to EPA scientists for detailed laboratory analysis.
For detailed information on EPA’s RadNet air monitor locations, click here.
NEI has uploaded two more videos to its YouTube channel. The first video discusses the design and safe operation of a nuclear reactor and the second video discusses dry cask storage for spent fuel at nuclear energy plants. Both videos feature Everett Redmond, NEI’s director of nonproliferation and fuel cycle policy.
UPDATE AS OF 1:30 P.M. EDT, MONDAY, MARCH 28:
Tokyo Electric Power Co. has detected isolated, low concentrations of plutonium in the soil at the Fukushima Daiichi nuclear power station. The density of plutonium is equivalent to the fallout that reached Japan from nuclear weapons testing during the Cold War, the company said.
TEPCO conducted analysis of plutonium contained in the soil collected on March 21 and 22 at five locations at the Fukushima Daiichi plant. Plutonium 238, 239 and 240 were detected, however just two of the samples may be the direct result of the recent incident, considering the ratio of the plutonium isotopes.
“The density detected in the plutonium is equivalent to the density in the soil under normal environmental conditions and therefore poses no major impact on human health,” TEPCO said. The company said it plans to strengthen environmental monitoring inside the station and surrounding areas.
The International Atomic Energy Agency today said it plans to conduct a high-level conference on nuclear safety “before the summer.” IAEA Director General Yukiya Amano said it is “vitally important that we learn the right lessons from what happened on March 11, and afterwards, in order to strengthen nuclear safety throughout the world.”
Amano said the conference should cover: an initial assessment of the Fukushima accident, its impact and consequences; lessons learned for the industry; strengthening nuclear safety; and strengthening the response to nuclear accidents and emergencies.
UPDATE AS OF 11:30 A.M. EDT, MONDAY, MARCH 28:
Radiation levels in the seawater near the Fukushima Daiichi nuclear power plant remained high on Monday, but dropped considerably from the levels reported on Sunday. Monday’s sampling near the plant’s south discharge outlet showed that radioactive iodine levels were 250 times normal, reduced significantly from 1,850 times normal.
Radiation dose rates also remained elevated in the turbine buildings of reactors 1, 2, 3 and 4. Tokyo Electric Power Co. on Monday said that workers had found similarly high radiation levels in water in drainage conduits outside reactors 1 and 2. The company said that rubble at reactor 3 prevented measures from being taken there on Monday.
TEPCO is pumping contaminated water from the basement of the turbine building at reactors 1 and 2 to the main condenser. The company also continued to pump fresh water into reactors 1, 2 and 3, using electrical-driven pumps rather than diesel-powered fire pumps.
Levels of radiation at the plant’s main gate ranged from 12.5 millirems per hour to about 20 millirem per hour. The U.S. Nuclear Regulatory Commission’s annual limit for occupational exposure is 5,000 millirem.
UPDATE AS OF 7:30 P.M. EDT, SUNDAY, MARCH 27:
The International Atomic Energy Agency, Tokyo Electric Power Company and the Nuclear and Industrial Safety Agency have reported no new developments at the Fukushima Daiichi nuclear power plant.
UPDATE AS OF 1:30 P.M. EDT, SUNDAY, MARCH 27:
U.S. Navy barges carrying 500,000 gallons of fresh water were nearing the Fukushima Daiichi nuclear power plant Sunday as workers continued to pump cooling water into reactors and spent fuel pools.
Beginning Friday, workers began to switch from sea water to fresh water to cool reactors 1, 2 and 3. The arrival of the barges will maintain the fresh water supply. Engineers are concerned that continued use of sea water will cause corrosion inside the reactors and hinder the cooling process.
Dose rates at the site boundary continued to range from 1 to 3 millirem per hour.
UPDATE AS OF 9:30 A.M. EDT, SUNDAY, MARCH 27:
Tokyo Electric Power Co. workers on Sunday were using pumps to remove highly contaminated water from the basement of the turbine building of reactors 1 and 2 at the Fukushima Daiichi nuclear power plant.
TEPCO also was preparing to remove water from the turbine building of reactor 3. Removal of the contaminated water is necessary to continue power restoration to the plant.
By Sunday, water injection to the pressure vessels at reactors 1, 2 and 3 had been switched from seawater to freshwater.
Off-site power has been restored to all units and work to connect equipment is ongoing. Progress is being slowed by high radiation levels and wet equipment.
TEPCO said that earlier reports of extremely high radiation levels measured in the water in the basement of the reactor 2 turbine building were inaccurate, according to news reports.
UPDATE AS OF 6 P.M. EDT, SATURDAY, MARCH 26:
At this time, sources such as the International Atomic Energy Agency, Tokyo Electric Power Co. and the Nuclear and Industrial Safety Agency have reported no new developments at the Fukushima Daiichi nuclear power plant. NEI will report on any new developments on this website on Sunday morning.
UPDATE AS OF 1:30 P.M. EDT, SATURDAY, 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, SATURDAY, MARCH 26:
Japanese scientists yesterday detected higher levels of 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.
UPDATE AS OF 7 P.M. EDT, FRIDAY, MARCH 25:
Freshwater 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 freshwater cooling. Reactor 2 is still being injected with seawater, but is expected to switch to freshwater 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 offshore 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.
UPDATE AS OF 1:30 P.M. EDT, FRIDAY, MARCH 25:
Workers have switched from sea water to fresh water to cool reactor 1 and were expected to make the same change for reactors 2 and 3 at the Fukushima Daiichi nuclear power plant by Saturday. Pressure and temperature inside reactor 1 were declining on Friday.
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.
UPDATE AS OF 9:30 A.M. EDT, FRIDAY, 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.
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.
UPDATE AS OF 7 P.M. EDT, THURSDAY, MARCH 24:
Restoration of electric power at reactors 1, 2 and 4 at the Fukushima Daiichi nuclear power plant has led to the reconnection of important reactor instrumentation, the International Atomic Energy Agency said.
Cooling water continues to be injected into reactors 1, 2 and 3. Reactors 5 and 6 at Fukushima Daiichi remain safely shut down. Both reactors were undergoing maintenance at the time of the earthquake.
Radiation dose rates inside the containment vessels of reactors 1 and 2 have decreased slightly, IAEA said.
External power has been reconnected to the common used fuel storage pool at the plant and cooling started on March 24 at 5:05 a.m. EDT, according to Japan’s Nuclear and Industrial Safety Agency. About 60 percent of the used uranium fuel rods at Fukushima plant are stored at this facility.
Radiation Monitoring Continues
Air samples collected at on-site monitors at the Fukushima Daiichi plant March 19-23 show that only iodine-131 was found to be in excess of Japanese government limits. Radiation dose rates measured on site March 21-23 have decreased from 193 millirem to 21 millirem per hour. Radiation dose rates at the plant’s site boundary ranged from 1 millirem to 3 millirem per hour on Thursday.
At distances between 34 and 73 kilometers to the west of the Fukushima Daiichi nuclear power plant, the dose rate ranged from .06 millirem to .69 millirem per hour.
Considerable variation in the levels of reported iodine-131 and cesium-137 continues in 10 prefectures, IAEA said. Food, milk and drinking water sampling has been most thorough and extensive in the Fukushima and Ibaraki prefectures, IAEA said.
Seawater samples collected at several points 30 kilometers from the coastline near the Fukushima Daiichi nuclear power plant found measurable concentrations of iodine-131 and cesium-137, IAEA said. The iodine concentrations were at or above Japanese regulatory limits. The cesium levels were well below those limits.
For more information on iodine-131, see NEI’s fact sheet Health Impacts of Iodine-131.
UPDATE AS OF 1:30 P.M. EDT, THURSDAY, MARCH 24:
In a sign of progress, Tokyo Electric Power Co. (TEPCO) is working to switch from seawater to borated freshwater to cool uranium fuel at three reactors at the Fukushima Daiichi nuclear power plant.
All reactors now have access to off-site power, and work is under way to inspect, repair and connect equipment needed to cool the reactors. Testing by TEPCO indicates that many pumps are inoperable because of flood damage.
Restoring regular cooling to the used fuel pools at Fukushima Daiichi remains a high priority. The used fuel pools at reactors 5 and 6 are being cooled using heat removal systems with electric power. Workers continue to spray seawater on the reactor buildings and spent fuel pools at reactors 1, 3 and 4. Cooling water to the spent fuel pool at reactor 2 is being supplied by a fire hose connection.
Overnight, steam was rising from the secondary containment buildings that house reactors 1 through 4.
Radiation dose rates at the site boundary range from 1 to 3 millirem per hour.
NEI has updated the brochure “Understanding Radiation: Its Effects and Benefits,” which includes facts about monitoring and protection against radiation.
UPDATE AS OF 9:30 A.M. EDT, THURSDAY, MARCH 24:
Two workers were hospitalized for radiation exposure Thursday, even as Tokyo Electric Power continued to make progress in stabilizing reactors at the Fukushima Daiichi nuclear power plant.
Three workers received radiation exposure of 17 to 18 rem from standing in contaminated water while laying cable in the reactor 3 turbine building, TEPCO said. One of the workers did not require hospitalization. The exposures were less than the 25 rem emergency dose limit established by the Japanese government.
External electric power was restored to reactor 1 and lights were on in the control room. Lighting was restored to the reactor 3 control room Wednesday. Electric power also has been connected to some of the instruments in all reactors except unit 3. While external electricity is available at all six units, it is not in wide use as workers inspect and repair cooling equipment before it can be energized. Reactors 5 and 6 have been safely shut down with cooling systems running on offsite power.
Seawater is being injected to cool the cores of reactors 1, 2 and 3. Workers continue to spray water into the spent fuel pools of reactors 3 and 4.
In Tokyo, the level of radioactive iodine in tap water has dropped to within safety limits Thursday. Yesterday, the Japanese government had advised against giving tap water to infants under one year old.
UPDATE AS OF 7 P.M. EDT, WEDNESDAY, MARCH 23:
Commissioners at the U.S. Nuclear Regulatory Commission on Wednesday voted to launch a two-pronged review of U.S. nuclear power plant safety in the aftermath of the March 11 earthquake and tsunami and the resulting events at the Fukushima Daiichi nuclear power plant.
The commission supported the establishment of an agency task force that will conduct both short- and long-term analysis of the lessons that can be learned from the situation in Japan. The results of their work will be made public.
“The longer-term review will inform any permanent NRC regulation changes” that are needed, the NRC said. The commission said it expects that the task force can begin the long-term evaluation in no later than 90 days and added that the task force should provide a report with recommended actions within six months of the beginning of that effort.
NRC inspectors at U.S. nuclear power plants will also support the task force’s short-term effort, supplemented as necessary by experts from the agency’s regional and headquarters offices, the NRC said.
“Examining all the available information from Japan is essential to understanding the event’s implications for the United States. We will perform a systematic and methodical review to see if there are changes that should be made to our programs and regulations to ensure protection of public health and safety,” NRC Chairman Gregory Jaczko said.
Smoke seen coming from the reactor building at reactor 3 at 4:20 p.m. on Wednesday (Japan time) “decreased significantly,” the International Atomic Energy Agency said. On Wednesday, smoke from reactor 3 caused the temporary evacuation of workers from reactors 3 and 4.
Efforts are continuing to restore off-site electricity at reactors 1, 2, 3 and 4.
As reported earlier here, seawater injection continues to cool reactors 1, 2 and 3. Seawater is being sprayed into the reactor 3 spent fuel pool. Crews continued to use a truck to deliver high volumes of water into the spent fuel pool at reactor 4, IAEA said.
UPDATE AS OF 2:30 P.M. EDT, WEDNESDAY, MARCH 23:
The U.S. Food and Drug Administration has blocked the import of milk, milk products, and fresh vegetables and fruits produced in areas surrounding the Fukushima Daiichi nuclear power plant. FDA is flagging all shipments from Japan to determine whether they originated from the affected area. The agency will test all food and feed shipments from areas near the plant.
Earlier, the Japanese government stopped the sale of raw milk, spinach and kakina (a local vegetable) from areas near the station.
Workers at the Daiichi site continue to inspect equipment to determine whether it can be connected to off-site power sources, which is now available at all six reactors. Off-site power has replaced the use of an emergency diesel generator to provide cooling to reactors 5 and 6, which had been shut down before the earthquake.
Seawater injection continues to cool reactors 1, 2 and 3, and seawater is being sprayed into the reactor 3 spent fuel pool. Water spray continues on the spent fuel pools at reactors 1, 3 and 4.
Radiation dose rates at the Daiichi site boundary continue to range from 1 to 3 millirem per hour.
NEI has also posted a new fact sheet, “Health Impacts of Iodine-131.”
UPDATE AS OF 11 A.M. EDT, WEDNESDAY, MARCH 23:
Workers continued efforts on Wednesday to restore off-site power to six reactors at the Fukushima Daiichi nuclear power plant. External power was available Wednesday at reactors 2, 3, 5 and 6, the Japan Atomic Industrial Forum said, but has not yet been re-established to reactor safety systems.
The next step before fully connecting external power is to test and repair the equipment that it will power. Cooling pumps for reactors 1 and 2 were covered by seawater and will require maintenance to bring them online. Tokyo Electric Power Co. is testing the cooling water pumps for reactor 3. External power was connected to the main control room at reactor 3 on Tuesday.
Reactors 5 and 6, which were shut down for maintenance at the time of the earthquake, are in safe shutdown.
“The earthquake and tsunami may have inflicted considerable damage in addition to knocking out electricity supplies,” the International Atomic Energy Agency said. “Since the extent of this damage (and therefore the extent of necessary repair) is unknown, it is not possible to accurately estimate a work schedule.”
Japanese authorities have detected high levels of radioactive cesium 137 in soil about 40 kilometers northwest of the Fukushima plant. Surveys of radioactive substances in soil at six locations found levels of cesium 137 that are 1,600 times typical for that area. Japan’s government is expanding offshore monitoring for radioactive nuclides to 30 kilometers.
Japanese authorities have advised Tokyo residents not to provide municipal drinking water to infants or use it in mixing powdered milk for infants because of abnormal levels of radioactive iodine (I-131) detected in the drinking water. One water sample (5,700 picocuries per liter) indicated approximately twice the Japanese government guideline and prompted the restriction for infants. In an emergency in the United States, state and local officials would closely monitor food and drinking water supplies and quarantine any contaminated supplies as needed to prevent public exposure. U.S. officials use pre-established guidelines for safe consumption of food and water set by the U.S. Food and Drug Administration.
The U.S. Department of Energy has released the first radiation data from its aerial monitoring system and ground detectors in Japan. The department will update the data regularly. For the latest information, click here.
UPDATE AS OF 7 P.M. EDT, TUESDAY, MARCH 22:
Tokyo Electric Power Co. reported this afternoon (U.S. time) that it has restored electricity to the control room at the Fukushima Daiichi reactor 3. Lights in the control room were switched on for the first time since the earthquake 11 days ago. Electricity to the reactor 4 control room is expected to be restored shortly.
Power restoration to the control rooms will help technicians as they seek to repair the two reactors’ cooling systems. Workers are seeking to reactivate control room monitoring systems for reactor parameters, such as reactor coolant temperatures and water levels. The company also reported that thermometers at reactors 1, 2 and 3 are working again.
TEPCO said it would try to reactivate a cooling pump for reactor 3 later today or Wednesday (U.S. time). The company said that if the pump functions normally, it could begin cooling the reactor and the spent fuel storage pool.
Workers at the Fukushima Daiichi plant also continued to spray water into the used fuel pools of reactors 3 and 4. A 160-foot long extension arm normally used to pour concrete for high-rise buildings was used to more accurately spray water into the used fuel pool area of reactor 4. Workers also pumped 18 tons of seawater into the reactor 2 used fuel pool.
Japan’s health ministry says it detected radioactive iodine levels in tap water above the national safety standard for infants at five locations in Fukushima Prefecture. The agency says the water does not pose an immediate risk to infants, but is advising against consumption of the water or adding water to powdered milk for infants.
Elevated levels of radioactive iodine and cesium were detected in soil about 25 miles from Fukushima Daiichi, but the levels do not pose a health risk, according to Japan’s science ministry.
UPDATE AS OF 4:30 P.M. EDT, TUESDAY, MARCH 22:
NEI has uploaded a new video, U.S. Nuclear Industry Taking Proactive Safety Measures, to its YouTube channel. The video features NEI Chief Nuclear Officer Tony Pietrangelo, who discusses the latest proactive steps taken by the industry to conduct an in-depth review of all U.S. nuclear facilities and emergency planning protocols to improve safety. NEI also updated its FAQ – Japanese Nuclear Energy Situation.
UPDATE AS OF 2:30 P.M. EDT, TUESDAY, MARCH 22:
According to the South Coast Air Quality Management District, which manages three radiation measurement areas for the U.S. Environmental Protection Agency, radiation levels in the United States have not exceeded natural background levels since before the earthquake and tsunami in Japan. These levels are thousands of times below any level that would result in public health impacts, the agency said.
Fukushima Daiichi Update
Power cables have been attached to all reactors at Japan’s Fukushima Daiichi nuclear plant, but the power distribution network at reactors 1 and 2 must be repaired before off-site electricity can be restored.
UPDATE AS OF 9:30 A.M. EDT, TUESDAY, MARCH 22:
Tokyo Electric Power Co. has reconnected external power supply at Fukushima Daiichi reactors 1, 2, 5 and 6. Off-site electricity is providing power to cooling pumps for the used fuel pools at reactors 5 and 6. Components and circuits at reactors 1 and 2 are being checked before power is restored to them. The company on Tuesday was installing cable at reactor 4 and power is expected to be restored at reactors 3 and 4 on Wednesday (Japan time).
TEPCO said the radiation level at the main gate at Fukushima Daiichi has declined from 33 millirem per hour to 25 millirem per hour.
Fire departments on Tuesday continued to pump water into the used fuel pools at reactors 3 and 4. Seawater is being pumped through a manually laid hose and sent to a water truck for continual spraying. Firefighters have sprayed a total of 3,600 tons of seawater, or about three times the pool’s capacity, in recent days.
Japan’s Chief Cabinet Secretary, Ukiyo Edano, reported the detection of low levels of iodine-131 and cesium-137 in seawater near the plant. There is no threat to human health, officials said.
Prime Minister Naoto Kan has ordered the governors of four prefectures (Fukushima, Ibaraki, Gunma and Tochigi) to suspend shipments of spinach and milk from specified areas. However, Kan said the levels of airborne radiation in those areas pose no risk to human health.
The Fukushima Daini reactors remain in safe condition today.
UPDATE AS OF 8 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.
Japan’s Chief Cabinet Secretary Yukio Edano announced that Prime Minister Kan has ordered the governors of four prefectures near Fukushima to restrict the shipment of spinach and kakina, another leafy vegetable. The shipment of milk from Fukushima prefectures was also restricted. Edano said the order was a precautionary emergency measure.
UPDATE AS OF 1:30 P.M. EDT, MONDAY, MARCH 21:
Workers were making progress Monday to bring off-site power to the Fukushima Daiichi nuclear plant. External electricity has been connected to reactor 2, and work continued to energize the reactor’s cooling systems. Reactors 5 and 6, and the used fuel pools at those reactors, were switched from backup diesel generators to the off-site power supply. Work also continued to establish electric service to reactors 3 and 4.
Spraying seawater into the spent fuel pools of reactors 3 and 4 and providing additional cooling water to fuel pool at reactor 2 continue to be a priority for TEPCO’s recovery workers. Water spraying at the Daiichi site’s common used fuel pool began Monday morning, the Nuclear and Industrial Safety Agency said.
Nuclear Regulatory Commission Briefing
Bill Borchardt, the executive director for operations at the U.S. Nuclear Regulatory Commission, briefed the agency’s commissioners Monday on the NRC’s response to the Fukushima accident in Japan. Borchardt’s slides and NRC Chairman Gregory Jaczko’s prepared remarks are available on the NRC website.
“We have a responsibility to the American people to undertake a systematic and methodical review of the safety of our own domestic nuclear facilities, in light of the natural disaster and the resulting nuclear emergency in Japan,” Jaczko said at the briefing. “Beginning to examine all available information is an essential part of our effort to analyze the event and understand its impact on Japan and the implications for the United States.”
UPDATE AS OF 10:30 A.M. EDT, MONDAY, MARCH 21:
Tokyo Electric Power Co. continued efforts on Monday to restore power to its reactors at Fukushima Daiichi as well as stabilize cooling in the used fuel pools of some reactors. Reactors 1, 2 and 3 are in stable condition and reactors 5 and 6 are stable and being cooled by systems powered by electricity that was restored over the weekend.
UPDATE AS OF 8:30 P.M. EDT, SUNDAY, MARCH 20:
Reactors 5 and 6 at the Fukushima Daiichi nuclear power plant are in cold shutdown, the International Atomic Energy Agency reports. This means that the reactors are in a safe mode, with cooling systems stable and under control, and with low temperatures and pressures.
When the quake struck, both reactors had been shut down for inspection and refueling and had some fuel inside the reactor cores. Tokyo Electric Power Co. has been using a pair of diesel generators at reactor 6 to pump water through the reactors and to their used fuel pools.
An elite firefighting unit sprayed water over the spent fuel pool of reactor 3, Japan’s Nuclear and Industrial Safety Agency reported.
Japan’s NISA reported that TEPCO early this morning began pumping sea water into the used fuel pool at reactor 2.
The company is checking individual circuits as it prepares to restore off-site electricity to the reactor’s main control room, where it will be able to check and monitor plant systems. To restore power to reactors 3 and 4, TEPCO is considering laying power cables to bypass a radiation contaminated area.
The March 11 earthquake was stronger than the Daiichi plant was designed to withstand, the Japan Atomic Industrial Forum reported. Maximum ground acceleration near reactor 3 was 507 centimeters per second squared – more than the plant’s design reference values of 449.
All four reactors at Fukushima Daini nuclear power plant are in cold shutdown with normal cooling.
Small amounts of radioactive iodine – less than a third of the safety limit – have been found in tap water in Tokyo and five other areas, the Japanese government reported. Earlier, radiation had been found in milk and spinach in areas near the reactor.
UPDATE AS OF 10 A.M. EDT, SUNDAY, MARCH 20:
A two-part operation to spray water into the used fuel pool at Fukushima Daiichi reactor 4 ended just before 7 a.m. EDT. Japan’s defense ministry announced that the Self Defense Force discharged more than 100 tons of water at the pool and concluded that much of it reached inside the reactor building.
This was the first time since the March 11 quake that reactor 4 has been doused. Yesterday the Tokyo elite fire services used a high-pressure fire truck to spray water for more than 13 hours into the fuel pool of reactor 3.
The ministry also reported conducting surface temperature measurements of reactors 1 through 4 from a helicopter to evaluate the effect of the water discharge operations. The surface temperature of each unit is below 100 degrees Celsius.
Tokyo Electric Power Co. said this morning that pressure within the reactor containment vessel from reactor 3 has begun to stabilize and has decided against an operation to vent gases to reduce pressure inside the containment vessel.
TEPCO is continuing work to restore electricity to reactor 2. A power cable has been connected from a nearby transmission line. TEPCO hopes to have power restored to the reactor’s control room sometime today. Connections to reactors 1, 3, 4, 5 and 6 are to follow.
Electricity is expected to be restored to both reactors 3 and 4 by March 23.
Radiation dose rates at monitoring posts are slightly higher than on past days. Rates at the plant site boundary range from 1 to 3 millirem per hour. Radiation dose rates in the area where fire trucks have been located are reported to be 2 to 3 rem per hour, with some isolated areas as high as 30 rem per hour.
All reactors are in cold shutdown and are stable.
UPDATE AS OF 8 P.M. EDT, SATURDAY, MARCH 19:
Powered by an emergency diesel generator, pumps are circulating cooling water in the spent fuel pools of reactors 5 and 6 at the Fukushima Daiichi nuclear power plant, according to reports. The company also added water to the used fuel pool at reactor 3 after elite firefighters from Tokyo spent 13 hours operating a high-pressure spray truck that pumped seawater into the pool.
The company and response workers were planning to spray water into the used fuel pool at reactor 4 on Sunday.
Electric power lines are connected to reactors 1 and 2, and engineers expected to bring power to the remaining reactors on Sunday, according to the Japan Atomic Industrial Forum. “We do not know if the water pumps [at Fukushima Daiichi] have been damaged and if they will work when power is restored,” the International Atomic Energy Agency said.
Tokyo Electric Power Co. reported that holes have been drilled into the ceilings of the buildings that house reactors 5 and 6 to prevent the buildup of hydrogen in the buildings.
All four reactors at Fukushima Daini nuclear power plant have reached cold shutdown conditions with normal cooling.
UPDATE AS OF 2 P.M. EDT, SATURDAY, MARCH 19:
Radiation doses at the Fukushima Daiichi nuclear power plant continue to decrease. Radiation dose rates at the site boundary of the Fukushima Daiichi nuclear power plant ranged from 1 millirem to 3 millirem per hour on March 18. Eighteen locations were monitored in a 30-kilometer to 60-kilometer radius of the plant. The highest radiation dose rate at any of those locations was 14 millirem per hour.
Tokyo Electric Power Co. (TEPCO) is installing high voltage cables from a nearby transmission line to reactors 1 and 2 at Fukushima Daiichi. Power is expected to be restored to reactors 1 and 2 later today (Saturday, March 19, Japan time). Priority is being given to restoring power to residual heat removal and cooling water pumps at the reactors. Plans are being made to extend high voltage cables to reactors 3 and 4 by March 21.
TEPCO also is stepping up efforts today to add water to the used fuel pool at reactor 4.
Two diesel generators are running and supplying electrical power to Reactors 5 and 6 at Fukushima Daiichi. A residual heat removal pump, powered by a diesel generator, is providing cooling to the spent fuel pool at reactor 5. Temperature in the spent fuel pool at reactor 5 is “high, but decreasing,” according to Japan nuclear industry sources.
There has been no change in the primary reactor containment structures at the Fukushima Daiichi plant. Crews are still pumping seawater into the reactors 1, 2 and 3 to cool the fuel.
All four reactors at Fukushima Daini have reached cold shutdown conditions with normal cooling being maintained using residual heat removal systems.
U.S. Public Opinion Data
U.S. public opinion on the safety of nuclear energy is relatively unchanged from 2008 levels despite the Fukushima accident, and 60 percent of Americans surveyed said the situation in Japan has made no difference in how they feel about nuclear energy in the United States.
Fox News Poll conducted by Anderson Robbins Research and Shaw & Co. Research. March 14-16, 2011. N=913 registered voters nationwide. Margin of error plus or minus 3.
“Do you believe nuclear power is a safe source of energy?”
|March 14-16, 2011||51||40||9|
|June 17-18, 2008||53||34||13|
“Has the current situation in Japan made you less likely to support using nuclear energy as a power source here in the United States, or has it not made a difference to how you feel?” If less likely: “Is that much less or just somewhat less likely?”
|.||Much less likely||Somewhat less likely||Not made a difference||Unsure|
|March 14-16, 2011||19||18||60||3|
UPDATE AS OF 10 A.M. EDT, SATURDAY, MARCH 19:
At a March 19 news conference, Japan’s Chief Cabinet Secretary Yukio Edano said that sea water injection is continuing at reactors 1, 2 and 3 at the Fukushima Daiichi nuclear power plant.
Preparations were being made to spray water into the used fuel pool at reactor 4, and an unmanned vehicle sprayed more than 1,500 gallons of water over seven hours into the used fuel pool at reactor 3, Edano said. He also said he believed that the situation at the reactor 3 fuel pool is stabilizing.
Some reactor cooling capacity has been restored at reactors 5 and 6 after the installation of generators at those reactors, Edano added.
Edano said that progress had been made on “a fundamental solution” to restore power at the Fukushima Daiichi nuclear power plant, with electricity expected to be restored at reactors 1 and 2 today and reactor 3 as early as Sunday.
Edano said that additional equipment was being transported to the site and that other means of providing cooling water to the pool is be examined.
Radiation dose at the west gate of the Fukushima Daiichi was 83 millirem per hour on March 18 at 7:10 p.m. EDT and dropped to 36 millirem per hour by 8 p.m. EDT, Edano said. Radiation levels have decreased since March 16. Although they are higher than normal, radiation levels near the reactors are within the range that allows workers to continue on-site recovery measures, the International Atomic Energy Agency said.
According to the IAEA, radiation dose rates in Tokyo and other areas outside the 30-kilometer zone remain far below levels which would require any protective action by the public.
All reactors at the Fukushima Daini nuclear power plant are in cold shutdown. (See the Japan Atomic Industrial Forum website.)
Radiation levels have increased above the federal government’s level in some food products from the Fukushima Prefecture and nearby areas. These levels were detected in samples of milk in Fukushima Prefecture and six samples of spinach in neighboring Ibaraki Prefecture, according to the Japan Atomic Industrial Forum. Edano said that if these products are consumed for a year, the total radiation dose would be equivalent to one CT scan.
Additional monitoring of food products is continuing in those regions.
UPDATE AS OF 9 P.M. EDT, FRIDAY, MARCH 18:
A World Health Organization spokesman said that radiation levels outside the 20-kilometer (12-mile) evacuation zone around the Fukushima Daiichi nuclear plant in Japan are not harmful for human health. He said the WHO finds no public health reason to avoid travel to unaffected areas in Japan or to recommend that foreign nationals leave the country. He also said there is no risk that exported Japanese foods are contaminated with radiation.
The Japanese government issued an advisory on Tuesday for people to evacuate from a 12-mile zone around the plant and also told people living within an 18-mile radius to stay indoors. Radiation levels at the plant boundary have been declining in the last day or so.
UPDATE AS OF 8 P.M. EDT, FRIDAY, MARCH 18:
Tokyo Electric Power Co. continued spraying water into the reactor 3 used fuel pool that began early Friday morning. Another water spraying operation into the pool was conducted around noon EDT. The company did not provide any updates on the status of the reactor 4 used fuel pool on Friday.
Operations to connect external power to reactors 1 and 2 are expected to continue through the weekend. TEPCO confirmed that electricity can be supplied to the reactors now that a new line has been connected from the off-site power system near the facility. Additional cabling and switchgear are being prepared to provide electricity to reactors 3, 4, 5 and 6.
TEPCO said it “planned to supply electricity for recovery efforts reactor 2 first, followed by reactors 1, 3 and 4 because reactor 2 is expected to be less damaged.” TEPCO plans to check pumps and other equipment and restore those items most vital to the cooling function.
No Radiation Levels of Concern in Western U.S.
The U.S. Department of Energy and Environmental Protection Agency on Friday issued a joint statement to confirm that the nationwide network of sensitive radiation monitoring equipment has detected no radiation levels of concern to U.S. citizens.
The EPA’s RadNet system notifies scientists in near real-time of elevated levels of radiation to enable them to determine whether protective actions are required. DOE’s IMS (International Monitoring System) operates as part of the Comprehensive Nuclear Test Ban Treaty and detects tiny quantities of radiation that may indicate an underground nuclear explosion anywhere in the world.
One of the DOE monitors in Sacramento, Calif., detected tiny quantities of a radioisotope (xenon-133). The level of the isotope detected would result in one-millionth of the dose rate that a person would normally receive from natural background sources.
More information is available at www.epa.gov/radiation.
UPDATE AS OF 5:30 P.M. EDT, FRIDAY, MARCH 18:
NEI has uploaded a new video to it YouTube channel. It features Constellation Energy’s director of radiation protection, Jeff Foster, putting the low radiation levels detected on the West Coast into context.
UPDATE AS OF 1:50 P.M. EDT, FRIDAY, MARCH 18:
NEI has uploaded two new videos to its YouTube channel. In the first, Alex Flint, NEI’s senior vice president of governmental affairs, welcomes President Obama’s effort to unify safety lessons from the Japan accident. The second features Flint discussing lawmakers’ questions about U.S. safety measures following events in Japan.
UPDATE AS OF 11:20 A.M. EDT, FRIDAY, MARCH 18:
Reactors 1, 2 and 3 at the Fukushima Daiichi nuclear power plant are in stable condition, with workers continuing to provide seawater cooling into the reactors. Containment integrity is believed to be intact on reactors 1, 2 and 3, and containment building pressures are elevated but are within design limits.
Site radiation doses have been decreasing since March 16. Radiation dose rates are fluctuating based on some of the relief operations, such as adding cooling water to the used fuel pools. Recent readings at the plant boundary are about 2 millirem per hour. Radiation dose rates at reactor 3 range between 2,500 and 5,000 millirem per hour.
The Japanese Self-Defense Force restarted cooling water spray into the Unit 3 reactor building and spent fuel pool at around 1 a.m. EDT on March 18. Plans are to spray 50 tons of water on the reactor 3 reactor building/spent fuel pool using seven firefighting trucks.
A diesel generator is supplying power to reactors 5 and 6. TEPCO is installing high voltage cables from a nearby transmission line to reactors 1 and 2. Once electricity supply is re-established, priority will be given to restoring power to reactor heat removal systems and cooling water pumps. Workers are seeking to install electrical cables to reactors 3 and 4 components in about two days.
All four reactors at Fukushima Daini remain shut down with normal cooling being maintained using residual heat removal systems.
Daiichi Accident Rated 5 on International Event Scale
New International Nuclear and Radiological Event Scale (INES) ratings have been issued for the accident at the Fukushima Daiichi and Daini nuclear power plants, the International Atomic Energy Agency said.
Reactor core damage at the Daiichi reactors 2 and 3 caused by a loss of cooling function has resulted in a rating of 5 on the seven-point scale.
The loss of cooling and water supply functions in the spent fuel pool of reactor 4 was rated a 3, or “serious” incident. The loss of cooling functions in the reactors 1, 2 and 4 of the Fukushima Daini nuclear power plant has led to a rating of 3.
The rating for the Chernobyl accident was 7, or a “major accident” on the INES scale. The Three Mile Island accident was 5, or an “accident with wider consequences.” For more information on INES, see the IAEA’s website and this IAEA leaflet.
UPDATE AS OF 10:20 A.M. EDT, FRIDAY, MARCH 18:
NEI has updated its Perspective on Radiation Releases and Emergency Planning at U.S. Nuclear Power Plants fact sheet.
UPDATE AS OF 10:20 P.M. EDT, THURSDAY, MARCH 17:
TEPCO continues to install cables, transformers and distribution equipment to restore off-site grid power to Fukushima Daiichi reactors 1 and 2. Reactor 1 has now been included in the power restoration plan.
Chief Cabinet Secretary Yukio Edano said in a recent conference that plans are in place to use 30 water cannon trucks and fire engines to spray water into the reactor 3 spent fuel pool, and TEPCO is discussing whether to do the same for the reactor 1 spent fuel pool. The spraying work is to be done in the next few hours, after the cable work is completed.
UPDATE AS OF 10 P.M. EDT, THURSDAY, MARCH 17:
NEI held a conference call on the morning of March 17, to update media on the latest actions by the U.S. nuclear energy industry in light of events in Japan. The audio of this conference call can be found on NEI’s YouTube channel.
UPDATE AS OF 9:15 P.M. EDT, THURSDAY, MARCH 17:
Tokyo Electric Power Co. said it hopes to activate the cooling system for Fukushima Daiichi reactor 2 “as early as Friday night” (Japan time). The company said it could restore power from the electric grid to reactor 2 by Thursday night (U.S. time).
The International Atomic Energy Agency reported that TEPCO completed connecting electrical cable from a makeshift transformer to reactor 2 at 4:30 a.. EDT. Engineers were waiting to complete spraying sea water into the reactor 3 fuel pool before they restore power through the cable to the reactor 2 cooling system.
TEPCO says that if it can provide power supply to the other reactors, it could begin restoring some cooling functions. The company said that after fire trucks injected water into reactor 3’s fuel pool, radiation levels at the plant’s west gate dropped from 31 millirem per hour to 29 millirem per hour at 10 a.m. EDT.
UPDATE AS OF 5:45 P.M. EDT, THURSDAY, MARCH 17:
NEI has uploaded three new videos to its YouTube channel. The first features Art Stall, former president and chief nuclear officer of NextEra Energy, discussing how the U.S. nuclear industry prepares for natural and man-made disasters. The second and third videos feature Jeff Merrifield, former NRC commissioner and senior vice president at The Shaw Group, discussing next steps for implementing lessons learned from Japan and confidence that construction of new U.S. nuclear plants should continue.
UPDATE AS OF 5 P.M. EDT, THURSDAY, MARCH 17:
It is unlikely that radiation released from the nuclear reactors in Japan will harm anyone in the United States, President Obama said in a press briefing this afternoon.
“We do not expect harmful levels of radiation to reach the United States, Hawaii, Alaska or U.S. territories in the Pacific,” Obama said. He added that the Centers for Disease Control and Prevention “does not recommend that people in the U.S. take precautionary measures other than staying informed.”
“Our nuclear plants have undergone exhaustive study and have been declared safe for any number of contingencies,” Obama said. However, he said that when there is an event such as the Fukushima accident, “we should learn from that. That’s why I have asked the NRC to do a comprehensive review of our nuclear plants” in light of the natural disaster that has happened in Japan.
In a briefing earlier on Thursday, Gregory Jaczko, chairman of the U.S. Nuclear Regulatory Commission, said, “There can’t be any harm to anyone in the United States” from the Japanese nuclear power plant.
Dan Poneman, the deputy secretary of energy, said today that two U.S. flights to Japan collected information on radiation levels. These readings informed the decision to recommend that Americans evacuate an area 50 miles from the Fukushima Daiichi nuclear energy facility.
Poneman expressed confidence in the safety of U.S. nuclear power plants, saying they’re evaluated on a “minute-by-minute” basis. Taking safety precautions “goes back decades,” he said. Tough safety standards have been in effect and upgraded since 1979, he said.
Status of Fukushima plants
In Japan, engineers have laid a power line that can connect reactor 2 of the Daiichi facility to the off-site power grid, the International Atomic Energy Agency reported. Workers are working to reconnect the power to reactor 2 after they complete spraying water into the reactor 3 complex to provide additional cooling to the used fuel pool. Reconnecting to the power grid is expected to enhance efforts to prevent further damage at the plant.
Japan’s Nuclear and Industrial Safety Agency reported on Thursday that the backup diesel generator for reactor 6 is working and supplying electricity to reactors 5 and 6. TEPCO is preparing to add water to the storage pools that house used nuclear fuel rods at those two reactors.
UPDATE AS OF 1:30 P.M. EDT, THURSDAY, MARCH 17:
Radiation readings at the Fukushima Daiichi site boundary were measured today at a lower level, between 2 and 3 millirem per hour.
UPDATE AS OF 11:35 A.M. EDT, THURSDAY, MARCH 17:
The reactors at the Fukushima Daiichi plant are in stable condition and are being cooled with seawater, but workers at the plant continue efforts to add cooling water to fuel pools at reactors 3 and 4.
The status of the reactors at the site is as follows:
Reactor 1’s primary containment is believed to be intact and the reactor is in a stable condition. Seawater injection into the reactor is continuing.
Reactor 2 is in stable condition with seawater injection continuing. The reactor’s primary containment may not have been breached, Tokyo Electric Power Co. and World Association of Nuclear Operators officials said on Thursday.
Access problems at the site have delayed connection of a temporary cable to restore off-site electricity. The connection will provide power to the control rod drive pump, instrumentation, batteries and the control room. Power has not been available at the site since the earthquake on March 11.
Reactor 3 is in stable condition with seawater injection continuing. The primary containment is believed to be intact. Pressure in the containment has fluctuated due to venting of the reactor containment structure.
TEPCO officials say that although one side of the concrete wall of the reactor 4 fuel pool structure has collapsed, the steel liner of the pool remains intact, based on aerial photos of the reactor taken on March 17. The pool still has water providing some cooling for the fuel; however, helicopters dropped water on the reactor four times during the morning (Japan time) on March 17. Water also was sprayed at reactor 4 using high-pressure water cannons.
Reactors 5 and 6 were both shut down before the quake occurred. Primary and secondary containments are intact at both reactors. Temperature instruments in the spent fuel pools at reactors 5 and 6 are operational, and temperatures are being maintained at about 62 degrees Celsius. TEPCO is continuing efforts to restore power at reactor 5.
All four reactors at the Fukushima Daini plant have reached cold shutdown conditions with normal cooling being maintained using residual heat removal systems.
UPDATE AS OF 11:30 A.M. EDT, THURSDAY, MARCH 17:
NEI has posted a new fact sheet, Perspective on Radiation Releases and Emergency Planning at U.S. Nuclear Power Plants.
UPDATE AS OF 9:30 P.M. EDT, WEDNESDAY, MARCH 16:
NEI has updated its YouTube channel with two more videos. The first addresses the U.S. industry’s response to the events in Japan and the second discusses natural, safe forms of radiation.
UPDATE AS OF 9 P.M. EDT, WEDNESDAY, MARCH 16:
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 the 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 resume efforts to spray water into the used fuel pool at the damaged reactor 4.
TEPCO also continues efforts to restore off-site power to the plant, with up to 40 workers seeking to restore electricity to essential plant systems by Thursday morning, March 17.
UPDATE AS OF 7:30 P.M. EDT, WEDNESDAY, MARCH 16:
NEI has added a new video, “NEI Offers Support to Japan,” to its YouTube page. Also available is an updated schematic of the reactor design at Fukushima Daiichi.
UPDATE AS OF 5:45 P.M. EDT, WEDNESDAY, MARCH 16:
U.S. Nuclear Regulatory Commission Chairman Gregory Jaczko told members of Congress today that there is no water remaining in the fuel pool at reactor 4 at Fukushima Daiichi nuclear power plant. Jaczko told members of the House Energy and Commerce Committee that “we believe that secondary containment has been destroyed and there is no water in the spent fuel pool … radiation levels are extremely high, which could impact the ability to take corrective measures.”
There is no updated information available from either Tokyo Electric Power or Japanese safety or regulatory officials on the status of the Fukushima plant. Japan’s Nuclear and Industrial Safety Agency said it also is concerned about the spent fuel storage pool at reactor 3 at the Fukushima Daiichi site.
Also testifying before the House committee, Energy Secretary Steven Chu restated the administration’s commitment to nuclear energy. “The American people should have full confidence that the United States has rigorous safety regulations in place to ensure that our nuclear power is generated safely and responsibly,” Chu testified. “Information is still coming in about the events unfolding in Japan, but the administration is committed to learning from Japan’s experience as we work to continue to strengthen America’s nuclear industry.
“Safety remains at the forefront of our effort to responsibly develop America’s energy resources, and we will continue to incorporate best practices and lessons learned into that process.” Chu said. “To meet our energy needs, the administration believes we must rely on a diverse set of energy sources, including renewables like wind and solar, natural gas, clean coal and nuclear power.”
The administration and Nuclear Regulatory Commission on Wednesday said that they believe it is appropriate for U.S. residents within 50 miles of the Fukushima reactors to evacuate. In response to nuclear emergencies, the NRC works with other U.S. agencies to monitor radioactive releases and predict their path. All the available information continues to indicate Hawaii, Alaska, the U.S. Territories and the U.S. West Coast are not expected to experience any harmful levels of radioactivity.
UPDATE AS OF 4:30 P.M. EDT, WEDNESDAY, MARCH 16:
Japanese authorities have reported concerns today about the condition of the used nuclear fuel pools at Fukushima Daiichi reactor 3 and reactor 4.
Officials also are preparing to spray water into reactor 4 from ground positions and possibly later into reactor 3. Some debris on the ground from the March 14 explosion at reactor 3 may need to be removed before the spraying can begin.
Most plants store used fuel in steel-lined, concrete vaults filled with water, which acts as a natural barrier for radiation from the used fuel. The water also keeps the fuel cool while the radiation decays—or becomes less radioactive. The water itself does not leave the used fuel pool.
Used nuclear fuel at the Fukushima-Daiichi plant is stored in seven pools (one at each reactor and a shared pool) and in a dry container storage facility (containing nine casks.)
The used fuel pools are designed so that the water in the pool cannot drain down as a result of damage to the piping or cooling systems. The pools do not have drains in the sides or the floor of the pool structure. The only way to rapidly drain down the pool is to have structural damage of the walls or the floor.
For more information on used fuel pools, see our new fact sheet, Used Nuclear Fuel Storage at the Fukushima Daiichi Nuclear Power Plant.
The U.S. government on Wednesday recommended that Americans within 50 miles of the Fukushima Daiichi plant evacuate the area. The Nuclear Regulatory Commission has posted this news release on its website regarding the evacuation recommendation.
The information contained in NRC’s recent press release is new and industry is still evaluating the radiation dose calculations since there is little context for the numbers provided in the press release. On the surface, the estimated doses look to be extremely conservative, but we have no additional information on which to evaluate them.
UPDATE AS OF 4:15 P.M. EDT, WEDNESDAY, MARCH 16:
NEI has posted an updated version of its Used Nuclear Fuel Storage at the Fukushima Daiichi Nuclear Power Plant fact sheet. Also available are updated responses to frequently asked questions on the Japan nuclear energy situation.
UPDATE AS OF 1:15 P.M. EDT, WEDNESDAY, MARCH 16:
NEI has a new fact sheet called Industry Taking Action to Ensure Continued Safety at U.S. Nuclear Energy Plants.
UPDATE AS OF 10 A.M. EDT, WEDNESDAY, MARCH 16:
News reports that high radiation levels led to the evacuation of all workers from the Fukushima Daiichi nuclear power station are not accurate. Workers were evacuated for about an hour but returned to the site to continue efforts to restore safe conditions at the plant.
Restoration of electrical power to the site was under way at the Daiichi plant as of 6 a.m. EDT Wednesday. A temporary cable was being connected between an off-site power line and Daiichi reactor 3. Off-site power has not been available at the site since the earthquake on March 11.
Reactors 1, 2 and 3 at the plant are being cooled with seawater. There is some level of uranium fuel damage at all three units, and containment structure damage is suspected at reactor 2.
Before the earthquake, reactor 4 had been in refueling and was completely defueled. Attempts to provide cooling water to the used fuel pool at reactor 4 by helicopter were not successful. Preparations are being made to inject water into the fuel storage pool using a high-capacity spray pump. There have been two fires inside the reactor containment building at reactor 4, but they have been extinguished. Although the reactor containment building at Unit 4 was damaged, the primary containment vessel remains intact.
At the Fukushima Daini site, all four reactors are safely shut down, and cooling functions are being maintained.
UPDATE AS OF 9 P.M. EDT, TUESDAY, MARCH 15:
At 5:45 a.m., March 16, Japan Standard Time (4:45 p.m. EDT, March 15), a fire reignited at Tokyo Electric Power Co.’s Fukushima Daiichi 4 reactor. The fire was extinguished after about two hours, TEPCO said.
TEPCO was planning to battle the fire and provide additional water to cool used nuclear fuel with water dumped from helicopters, but abandoned the plan because a hole in the building’s roof is not in close proximity of the used fuel pool.
The company may remove some panels from the top of the reactor containment buildings at reactors 5 and 6 in order to avert a possible buildup of hydrogen in the reactors. Hydrogen buildup caused explosions at reactors 1 and 3.
All of the fuel rods had been moved from reactor 4 to the spent fuel pool due to the maintenance work. About one-third of the fuel rods in reactors 5 and 6 had been removed as part of maintenance and refueling activities.
Seventy percent of the fuel rods in Unit 1 and one-third in Unit 2 have been damaged, TEPCO said. The cooling water level in both units is being maintained.
Weather reports indicate that the wind at the Fukushima plant has shifted and is now blowing out to the Pacific.
An earthquake registering 6.1 on the Richter scale struck the Eastern Honshu region of Japan. Hamaoka nuclear plant, about 100 kilometers (62 miles) from the epicenter, continues to operate normally.
UPDATE AS OF 5 P.M. EDT, TUESDAY, MARCH 15:
NEI has posted a new fact sheet, Used Nuclear Fuel Storage at the Fukushima Daiichi Nuclear Power Plant.
UPDATE AS OF 2:15 P.M. EDT, TUESDAY, MARCH 15:
An explosion at Unit 2 of the Fukushima Daiichi plant earlier today has damaged the suppression chamber, which holds water and steam released from the reactor core. Personnel not directly supporting recovery efforts have been evacuated from the plant, with about 50 employees remaining, principally to restore cooling water in the reactors.
Later in the day, water level inside the Unit 2 reactor was measured at 1.7 meters below the top of the fuel rods, but it was rising as workers pumped sea water into the reactor, reports said.
Tokyo Electric Power Co. said that an oil leak in a cooling water pump at Unit 4 was the cause of a fire that burned for approximately 140 minutes. The fire was not in the spent fuel pool, as reported by several media outlets. Unit 4 was in a 105-day maintenance outage at the time of the earthquake and there is no fuel in the reactor.
All four reactors at the Fukushima Daini power plant are shutdown and reactor coolant systems are keeping the reactors safe.
Residents have been evacuated from the area surrounding the facility and they have been given potassium iodide tablets as a preventive measure. The ingestion of the tablets can help prevent the accumulation of radioactive iodine in the thyroid.
The U.S. Nuclear Regulatory Commission has sent 11 experts to Tokyo to provide assistance requested by the Japanese government. Two reactor experts were dispatched Saturday; others began departing Monday.
Energy Secretary Steven Chu said today that nuclear energy is safe and important to the country’s energy portfolio. Americans “should have full confidence that the United States has rigorous safety regulations in place to ensure that our nuclear power is generated safely and responsibly.”
In testimony before the House of Representatives, Chu said: “Safety remains at the forefront of our effort to responsibly develop America’s energy resources, and we will continue to incorporate best practices and lessons learned into that process.” He said the country must rely on several energy sources, including nuclear.
Sen. Jeff Bingaman, chairman of the Energy and Natural Resources Committee, said in a statement, “I think undoubtedly they’ll (Nuclear Regulatory Commission) be taking a fresh look at the safety precautions and provisions that are in place, in light of whatever is learned from the Japanese. I hope that the Commission will quickly reach some conclusions about whether the safety precautions and provisions that it has insisted on are adequate for the future.”
UPDATE AS OF 10:20 A.M. EDT, TUESDAY, MARCH 15:
The radiation level at the Fukushima Daiichi nuclear power plant has been decreasing, according to the International Atomic Energy Agency.
At 8 p.m. EDT March 15, a dose rate of 1,190 millirem per hour was observed. Six hours later, the dose rate was 60 millirem per hour, IAEA said.
About 150 residents near the Fukushima Daiichi site have been checked for radioactive contamination and 23 have been decontaminated.
Japanese authorities have distributed potassium iodide tablets to evacuation center. (See this page for more information on potassium iodide). If taken within several hours of absorbing radioactive iodine, potassium iodide can protect the thyroid gland.
UPDATE AS OF 9:15 A.M. EDT, TUESDAY, MARCH 15:
Units 1 and 3 at Fukushima Daiichi are stable and cooling is being maintained through seawater injection. Primary containment integrity has been maintained on both reactors.
The Japan Atomic Energy Agency (JAEA) reported an explosion in the suppression pool at Fukushima Daiichi Unit 2, at 7:14 p.m. EDT on March 14. Reactor water level was reported to be at 2.7 meters below the top of the fuel. The pressure in the suppression pool decreased from 3 atmospheres to 1 atmosphere. Radiation readings at the site increased to 96 millirem per hour.
Dose rates at Fukushima Daiichi as reported at 10:22 p.m. EDT on March 14 were:
- Near Unit 3 reactor building 40 rem/hr
- Near Unit 4 reactor building 10 rem/hr
- At site boundary 821 millirem/hr
- Kitaibaraki (200 km south of site) 0.4 millirem/hr
We are working on getting updated information on radiation and dose rates at and near the plant.
Station personnel not directly supporting reactor recovery efforts have been evacuated, leaving approximately 50 staff members at the site. Operators are no longer in the main control room due to high radiation levels.
Safety relief valves were able to be reopened and seawater injection into the reactor core was restarted around 1 a.m. EDT on March 15 and is continuing.
At Unit 4 on March 14 at approximately 8:38 p.m. EDT, a fire was reported in the reactor building. It is believed to have been from a lube oil leak in a system that drives recirculation water pumps. Firefighting efforts extinguished the fire. The roof of the reactor building was damaged.
All four reactors at Fukushima Daini are being maintained with normal cooling using residual heat removal systems.
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. Firefighters are responding to the fire. The reactor does not have fuel, but there is spent fuel in the reactor pool and Edano said he assumes radioactive material is 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. Japan time. A hole was observed in the No. 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 was 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.
UPDATE AS OF 9:40 P.M. EDT, MONDAY, MARCH 14:
An explosion in the vicinity of the suppression pool at Fukushima Daiichi 2 just after 6:20 a.m. Japan Standard Time (5:20 p.m. EDT) may have damaged a portion of the reactor’s primary containment structure.
Pressure in the suppression pool has been reported to have decreased to ambient atmospheric pressure shortly after the blast. Plant operator Tokyo Electric Power Co. (TEPCO) has reported possible damage to the reactor’s pressure-suppression system. Radiation levels at local monitoring stations have risen but are still in flux. TEPCO has evacuated some workers from all three Fukushima reactors with the exception of approximately 50 workers involved in sea water pumping activities into the reactors as part of emergency cooling efforts.
Residents within a 20-kilometer (12.5-mile) zone around the plant were ordered to evacuate on Saturday following a hydrogen explosion at Unit 1. Another hydrogen explosion occurred this morning (U.S. time) at Unit 3.
Efforts to inject sea water into Unit 2 have been complicated by a faulty pressure relief valve. The fuel at Unit 2 has been exposed at least twice, before being re-covered with sea water.
Japan’s chief cabinet secretary, Yukio Edano, has said a partial defect has been found inside the containment vessel of reactor 2 at the Fukushima Daiichi nuclear power plant.
UPDATE AS OF 5:30 P.M. EDT, MONDAY, MARCH 14:
Tokyo Electric Power Co. reported at 3 p.m. EDT that work had resumed to pump seawater into Fukushima Daiichi 2 to maintain safe cooling water levels after the utility was able to vent steam from the pressure vessel. The fuel had been exposed for 140 minutes Monday night due to a malfunctioning pressure relief valve. Water levels later went up to cover more than half of the rods.
The U.S. Nuclear Regulatory Commission reports that the Japanese government has formally asked for assistance from the United States on nuclear power plant cooling issues triggered by the March 11 tsunami.
The agency has already sent two experts on boiling water reactor issues to Japan as part of a U.S. Agency for International Development disaster relief team. The experts now are in Tokyo providing technical assistance. The U.S. NRC is also monitoring the Japanese reactor events around the clock from its headquarters operations center in Rockville, Md.
Prior to the second exposure of the rods around 11 p.m., March 14 local time in Japan, radiation at the plant site was detected at a level twice the maximum seen so far – 313 millirem per hour, according to TEPCO.
Chief Cabinet Secretary Yukio Edano said he believes the problem at the plant ”will not develop into a situation similar to Chernobyl,” even in the worst case.
The utility said a hydrogen explosion at the nearby No. 3 reactor that occurred Monday morning may have caused a glitch in the cooling system of the No. 2 reactor.
The hydrogen explosion at reactor 3 on March 14 injured 11 people: seven TEPCO workers at the site and four members of the country’s Self-Defense Forces. The reactor’s containment vessel was not damaged and the reactor remains safely contained in its primary containment.
Administration, NRC Response to the Accident
At a White House briefing, press secretary Jay Carney said that information is still coming in on the status of nuclear plants in Japan, but that the Obama administration is committed to keeping nuclear energy as part of the U.S. energy portfolio.
Energy Department Deputy Secretary Daniel Poneman said nuclear energy “continues to play an important role in providing a low-carbon future.”
Gregory Jaczko, chairman of the Nuclear Regulatory Commission, said at the briefing that analysis of the damage, the type of reactor and the distances involved indicate a “very low likelihood” that any potential fallout from Japan might reach Hawaii or Western states.
U.S. nuclear power plants are built to endure the strain of natural phenomena like hurricanes, earthquakes and tornadoes, Jaczko said. “Right now, we continue to believe that nuclear power plants in this country operate safely and securely,” he said.
UPDATE AS OF 4:20 P.M. EDT, MONDAY, MARCH 14:
NEI has posted a new document, Radiation in Perspective, which describes where radiation comes from and how it is measured.
UPDATE AS OF 1:30 P.M. EDT, MONDAY, MARCH 14:
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 remover 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.
UPDATE AS OF 11 A.M. EDT, MONDAY, MARCH 14:
Fuel rods in the reactor vessel of Unit 2 at the Fukushima Daiichi Power Plant were temporarily uncovered from cooling water today, but seawater injection has raised the water level to the halfway point, Tokyo Electric Power Co. (TEPCO) said. Seawater is now being used to cool all three Daiichi reactors that were shut down after the March 11 earthquake. Unit 2 had lost its emergency cooling capacity. Workers were preparing to remove hydrogen from the reactor building, and TEPCO has opened the steam relief valve of the reactor.
The primary containment vessels and reactor cores of reactors 1 and 3 at the Fukushima Daiichi facility are intact, following earlier hydrogen explosions in the secondary containment buildings of both reactors.
At Unit 1, seawater injection continues to cool the reactor. Safety regulators consider the reactor’s pressure an indication of a stable condition. The hydrogen explosion on March 11, which occurred between the primary containment vessel and the containment building, did not damage the primary containment vessel or the reactor core. To control the pressure of the reactor core, TEPCO has been injecting seawater and boric acid into the primary containment vessel of Unit 1 since March 12.
A hydrogen explosion Monday at Unit 3, similar to the Unit 1 explosion, did not damage the primary containment, Japan’s Nuclear and Industrial Safety Agency (NISA) said. The control room remains operational, and a government official said that pressure in the reactor vessel is stable. After the explosion, the few hundred people remaining in the 12.5-mile evacuation zone were asked to stay indoors.
At the Fukushima Daini site, cooling capability has been re-established for Unit 4 at the reactor. Units 2 and 4 are in cold shutdown.
UPDATE AS OF 11:30 P.M. EDT, SUNDAY, MARCH 13:
At 11:01 p.m. EDT, Tokyo Electric Power Co. confirmed that an explosion occurred at Fukushima Daiichi Unit 3. The reactor’s building wall and ceiling were blown off. TEPCO officials said it was likely a hydrogen explosion as occurred at Unit 1 Friday, but did not have enough information to confirm this.
UPDATE AS OF 7 P.M. EDT, SUNDAY, MARCH 13:
The hydrogen explosion on March 11 between the primary containment vessel and secondary containment building of the reactor did not damage the primary containment vessel or the reactor core. To control the pressure of the reactor core, Tokyo Electric Power Co. began to inject seawater and boric acid into the primary containment vessels of Unit 1 on March 12 and Unit 3 on March 13. There is likely some damage to the fuel rods contained in Units 1 and 3.
At both Units 1 and 3, seawater and boric acid is being injected into the reactor using fire pumps. On Unit 3, a pressure relief valve in the containment structure failed to open, but was restored by connecting an air pressure to the line driving valve operation.
The water level in the reactor vessel of Unit 2 is steady.
Personnel from TEPCO are closely monitoring the status of all three reactors.
The highest recorded radiation level at the Fukushima Daiichi site was 155.7 millirem per hour at 1:52 p.m. EDT on March 13. Radiation levels were reduced to 4.4 millirem per hour by the evening of March 13. The U.S. Nuclear Regulatory Commission’s radiation dose limit for the public is 100 millirem per year.
Japanese government officials acknowledged the potential for partial fuel meltdowns at Fukushima Daiichi units 1 and 3 reactors, but there is no danger for core explosion, as occurred at the nuclear power station at Chernobyl in 1986. Control rods have been successfully inserted at all of the reactors, thereby ending the chain reaction. The reactor cores at Fukushima Daiichi and Daini power stations are surrounded by steel and concrete containment vessels of 40 to 80 inches thick that are designed to contain radioactive materials.
The Fukushima Daini plants remains in a state of emergency. There is electricity available at all four of the reactors at Fukushima Daini, although there is limited availability of the cooling water pumps at units 1, 2 and 4.
TEPCO is working to maintain constant cooling in the primary containment vessels of those reactors. No radioactivity has been recorded outside of the secondary containment buildings at Fukushima Daini, according to TEPCO.
Two other nuclear power plants in the Tohoku region, Onagawa Nuclear Power Station and Tokai Nuclear Power Station, were automatically shut down in response to the earthquake. The four reactors at these plants have functioning cooling systems and are being monitored by plant operators.
The Rokkasho Reprocessing Plant and accompanying facilities, located far north of the tsunami zone in Rokkasho Town, is operating safely on backup power generation systems.
Japanese nuclear facilities are designed to withstand powerful seismic events, such as earthquakes. In this earthquake—the strongest recorded over the past 100 years in Japan—the containment structures of Fukushima Daiichi maintained their structural integrity. These facilities were designed to withstand tsunamis within a range of assumed strength; however, the force of the tsunami on March 10 exceeded the assumed range and flooded diesel generators at Fukushima Daiichi power station. This precipitated the loss of power for the reactor cooling systems.
The automatic shutdown of the 11 operating reactors at the Onagawa Nuclear Power Station, Tokai Nuclear Power Station, Fukushima Daiichi and Daini, represents a loss of 3.5 percent of electric generation capacity for Japan.
UPDATE AS OF 5 P.M. EDT, SUNDAY, MARCH 13:
NEI has compiled nearly 20 frequently asked questions on the Japanese nuclear energy situation. The FAQ describes current efforts that are underway in Japan, including detailed information about the boiling water reactor design and potential impacts for the U.S. nuclear industry.
UPDATE AS OF 8:30 A.M. EDT, SUNDAY, MARCH 13:
Tokyo Electric Power Co. continues to implement emergency cooling and pressure relief operations at Fukushima Daiichi nuclear power station. In addition, at Fukushima Daini, three reactors remain shut down. They have electrical power available at Daini, but the suppression water pools used for reactor cooling are saturated at both sites.
There is a state of emergency declared at Fukushima Daiichi 1, 2 and 3. The company is venting containment structures at reactors 1 and 3. Reactor 3 uses mixed-oxide fuel. Electrical power is not available at any of the reactors at this site and there is not backup power available at units 1, 2 and 3. TEPCO has been pumping seawater into reactors 1 and 3 to maintain cooling and there is some uranium fuel rod damage suspected at both reactors. Public evacuation has been ordered and executed in a 12-mile radius and there have been low levels of radiation released into the environment as a result of venting and the explosion at Unit 1 secondary containment. The maximum reported dose at the site is 128 millirem per hour. One worker at the site has received a radiation dose of 10.6 rem.
There is a state of emergency at units 1, 2 and 4 and evacuation has been ordered and executed for 2.5 miles around the plant. There has been no radioactive release reported at the site. There is electric power available at all four reactors at the site, but there is limited use of cooling water pumps at units 1, 2 and 4 due to damage from the tsunami. The suppression pools are saturated at all three reactors.
Comments From Japanese Officials
The company is providing seawater and boron for core cooling at Fukushima Daiichi units 1 and 3 and is venting containment at the reactors, Japan’s Chief Cabinet Secretary, Yukio Edano, said on Sunday. Officials are acting on the assumption that a meltdown could be underway at Fukushima Daiichi Unit 3. “Unlike the No. 1 reactor, we ventilated and injected water at an early stage,” Edano said.
Authorities are preparing to distribute iodine to protect people from radioactive exposure.
UPDATE AS OF 7:30 P.M. EST, SATURDAY, MARCH 12:
Unconfirmed reports indicate that an emergency has been declared at a second reactor at the Fukushima Daiichi nuclear power plant.
The Associated Press and the Los Angeles Times report that the Japanese Nuclear and Industrial Safety Agency said early Sunday that the Unit 3 cooling system had malfunctioned. The report said that Tokyo Electric Power Co. alerted the agency.
Clarifying earlier reports, Ichiro Fujisaki, ambassador of Japan to the United States, said no explosion occurred in the reactor containment at Fukushima Daiichi’s Unit 1. Fujisaki told CNN during its 6 p.m. EST broadcast on March 12 that officials are taking steps to stabilize two other shut down reactors at the site. He confirmed that none of six reactors at the site were in danger of a meltdown.
“There are other issues with the reactor [Unit 1] as well. We are taking up vapor because of the increasing pressure in the containment,” Fujisaki said. “We do not see any evidence of that (a meltdown). We are getting information every hour on this issue.
“We are working every minute and every second to get this situation under control,” Fujisaki continued. “We are putting in water and taking out vapor. The radioactive number is decreasing. We are taking the most cautious attitude and that’s what is most important.”
Fujisaki said Japan is consulting with other countries to resolve the situation. ”In this kind of situation, what is most important is speed and mobilizing all of the forces.”
TEPCO, Japan’s electricity utility, reports no elevated radiation levels at the boundary of another facility, the Fukushima Daini nuclear power station, which also closed after the earthquake.
“No radiation impact to the external environment has been confirmed,” TEPCO said of the Fukushima Daini plant.
UPDATE AS OF 5 P.M. EST, SATURDAY, MARCH 12:
NEI has created a new fact sheet, Events at the Fukushima Daiichi Nuclear Power Plant in Japan, to summarize the events unfolding at the Fukushima Daiichi nuclear power plant.
UPDATE AS OF 12:30 P.M. EST, SATURDAY, MARCH 12:
The incident at Fukushima Daiichi has received a level 4 rating on the International Atomic Energy Agency’s (IAEA) International Nuclear and Radiological Event Scale (INES), lower than both the 1986 Chernobyl disaster (rated 7 on the seven-point scale) and the 1979 Three Mile Island accident (rated 5).
Japanese authorities did not give radiation measurements in their INES report to the IAEA, but plant operator Tokyo Electric Power Co., reported that radiation levels next to the Unit 1 machine building had increased from 0.007 rem per hour to 0.67 rem per hour.
TEPCO confirmed it has successfully vented the containment of Unit 1 and was preparing to vent units 2 and 3. Venting reduces pressure in the containment. Boric acid and sea water are being used to cool the plant’s Unit 1 reactor.
A government official attributed an explosion earlier today to accumulated hydrogen combined with oxygen in the space between the containment and the outer structure. The primary containment was not damaged, he said.
UPDATE AS OF 9:30 A.M. EST, SATURDAY, MARCH 12:
The Tokyo Electric Power Co. says it has successfully vented the containment of Unit 1 at the Fukushima Daiichi nuclear power plant in northern Japan, according to several industry sources.
Japan’s chief cabinet secretary, Yukio Edano, told a news conference that there was an explosion at Fukushima Daiichi at 15:36 local time, but he said it has not affected the reactor’s primary system or its containment, the news service NucNet reported this morning.
Edano said there was hydrogen explosion in the space between the concrete containment and the reactor’s primary system, but the explosion did not damage the containment function or the reactor system, the report said (see NEI’s graphic here). A portion of the fuel in the reactor was uncovered and TEPCO is using borated seawater to cover the fuel. Radiation measurements at the site boundary of Fukushima Daiichi were measured at 11 millirem per hour, but were reduced to 7 millirem per hour a few hours after the explosion.
TEPCO also is preparing to vent the containment structures at Fukushima Daiichi 2 and 3, as of Saturday morning.
Edano said, “We’ve confirmed that the reactor container was not damaged. The explosion didn’t occur inside the reactor container. As such there was no large amount of radiation leakage outside.”
The Japanese government expanded the evacuation zone around the facility to 20 kilometers, or about 12 miles.
Backup diesel generators and backup batteries have arrived at the Fukushima Daiichi reactors.
U.S. support to Japan for the nuclear plant events and earthquake includes assistance from the industry and U.S. Nuclear Regulatory Commission.
TEPCO also is working to maintain safe condition of Fukushima Daini units 1, 2 and 3, which have lost reactor pressure suppression function.
The nuclear facilities were damaged in a magnitude 8.9 earthquake on March 11, centered offshore of the Sendai region, which contains the capital Tokyo. Serious secondary effects followed including a significant tsunami, significant aftershocks and a major fire at a fossil fuel installation.
UPDATE AS OF 8 A.M. EST, SATURDAY, MARCH 12:
NEI is coordinating with the Institute of Nuclear Power Operations (INPO) and the Electric Power Research Institute (EPRI) this morning and will provide a further update to the situation in Japan as soon as possible.
UPDATE AS OF 5 P.M. EST, FRIDAY, MARCH 11:
Pressure inside the containment of Unit 1 at Fukushima Daiichi reportedly has been increasing over the time that emergency core cooling systems have not been active. TEPCO reported at 2 a.m. local time that pressure had increased beyond plant reference levels, but was within engineered limits. The company said it will reduce the pressure within containment “for those units that cannot confirm certain level of water injection” by the safety systems. “We will endeavor to restore the units and continue monitoring the environment of the site periphery,” TEPCO’s press release states.
The Federation of Electric Power Companies in Japan released a statement indicating that “slightly radioactive vapor will be passed through a filtering system and emitted outside via a ventilation stack.” TEPCO “is confident that this controlled release will help maintain the integrity of the reactor containment vessel while having no impact on health or the environment.”
In the aftermath of the Japanese earthquake, Pacific Gas & Electric declared an unusual event at its Diablo Canyon plant, located near San Luis Obispo, Calif., as a precaution for a potential tsunami. “All plant safety systems and components remain in normal operating condition and both units are currently operating at 100 percent power,” PG&E reported.
Southern California Edison said that the San Onofre plant, located next to San Onofre State Beach in California, continues to operate safely and that a tsunami advisory remains in effect in the region. “The San Onofre Generating Station has not reported any unusual activity,” the company reported. “All operations continue normally. The plant’s protective measures include a reinforced wall 30 feet above sea level.”
UPDATE AS OF 8 A.M. EST, FRIDAY, MARCH 11:
The magnitude 8.9 earthquake hit at 2:46 p.m. Japan time on March 11, centered offshore of the Sendai region, which contains the capital Tokyo. Serious secondary effects followed including a significant tsunami and a major fire at a fossil fuel installation. The earthquake comes just two days after a magnitude 7.3 earthquake hit, also offshore, in the same general region.
The Japan Atomic Industry Forum (JAIF) issued a notice saying that all 11 reactors in the northeastern part of Japan that were operating had shut down automatically. It noted that the Nuclear and Industrial Safety Agency (NISA) said no damage to nuclear power plants had been reported as of 3:16 p.m. local time. Japanese Prime Minister Naoto Kan made a statement on television in which he noted that there was no indication of any radioactive release.
Tokyo Electric Power Co. said that emergency diesel generators started as expected, but then stopped inexplicably after an hour and all emergency power was lost, leading them to notify the government of a potential “emergency” situation, in which local authorities could take precautionary measures with the nearby communities and evacuate them if necessary. About nine hours later, the Ministry of Economy, Trade and Industry said that three of four mobile power supply modules had arrived at the plant to supply emergency power and engineers were connecting the cables. Other supply modules were arriving via air. NISA noted that emissions from the exhaust stack showed no increase in radioactivity.
Tohoku Electric Power Co. also reported a fire in the non-nuclear turbine building at Onagawa Unit 1.
A tsunami warning was issued for most of the Pacific Ocean, including Taiwan where six nuclear reactors operate. There is no tsunami concern for nuclear power plants in South Korea or China.