In This Section
UPDATE AS OF 4 P.M. EDT, FRIDAY, APRIL 29:
Below is a round-up of noteworthy news that happened this week with regard to the Fukushima Daiichi nuclear plant and the U.S. nuclear industry’s response.
- Priorities this week at Fukushima continued to be cooling the reactors and fuel pools, draining water from the turbine buildings and concrete structures that house piping to reduce radiation levels, and containing the spread of radioactive materials. Tokyo Electric Power Co. (TEPCO) is increasing the amount of cooling water injected into reactor 1 at the Fukushima Daiichi plant as part of a plan to cover the fuel.
- TEPCO plans to build a storage and processing facility that can hold 70,000 tons of highly radioactive water at the plant.
- Overall, site radiation dose rates are stabilizing or decreasing. The most recent radiation readings reported at the plant site gates ranged from 4.8 millirem per hour to 2.2 millirem per hour. TEPCO has released a map showing radiation levels around the site, based on readings taken on different days since the incident began.
- TEPCO said this week that it will build a wall of sandbags along the shoreline at the Fukushima Daiichi site as a temporary measure against another possible tsunami. The company also moved emergency power generators to higher ground to prevent the reactors’ cooling systems from failing in case a major tsunami hits the plant again. The utility will sandbag the shoreline at the plant to a height of several meters. Priority will be put on the area near the waste processing facility, where highly radioactive water is being moved from around the reactor buildings. TEPCO is also planning to build a breakwater on the shoreline, as the sandbags cannot remain the long-term solution for a possible tsunami.
- Japan’s Nuclear Safety Commission (NSC) asked the government April 28 to review the ability of the country’s nuclear power plants to withstand earthquakes. The commission has requested that the Nuclear and Industrial Safety Agency “re-examine the fault lines and geographical changes where plant operators have so far said the risk of earthquake damage was low.” The utilities’ reassessment of earthquake resistance “will likely take several years,” the NSC said, and will likely affect the start of operations at new nuclear power plants and the construction of new reactors.
- TEPCO said April 28 that it does not believe the spent fuel pool at reactor 4 of Fukushima Daiichi is leaking, according to a report by Japan television station NHK. The utility said it initially believed that declining water levels in the pool indicated that it might have been damaged in an explosion soon after March 11, but it “now believes that the water has been evaporating at a rate in line with calculations by experts.” The fuel storage pool “will be reinforced by July,” TEPCO said.
- The U.S. Nuclear Regulatory Commission (NRC) site inspections as a follow-up to the Fukushima event were set to end. A draft report of the results is expected in two weeks.
- The NRC staff briefed the commissioners Thursday on its review of the Fukushima accident and on the station blackout rule (see archived webcast here). Bill Borchardt, the NRC’s executive director for operations, told the commissioners that NRC reviews of the accident at Fukushima Daiichi “have not identified anything that needs immediate action” at U.S. reactors. The briefing also explored preparations at U.S. reactors for a total loss of AC power, or station blackouts. NRC Chairman Gregory Jaczko said he is “not convinced that in that situation (station blackout), four hours is a reasonable time to restore off-site power. That may be something we want to look at a little bit more.”
- The Group of 20 economic powers (G-20) will meet June 7-8 to discuss nuclear safety “in light of the events” at Japan’s Fukushima nuclear power plant, OECD Secretary-General Angel Gurria said this week. The International Atomic Energy Agency also will take part in the G-20 meeting.
New NEI Products:
- A new fact sheet on relicensing and the safety of nuclear energy plants.
- A new video on radiation monitoring, featuring Health Physics Society President Edward Maher, appears on NEI’s YouTube channel.
- Alex Marion, NEI’s vice president for nuclear operations, briefly discussed implications of Fukushima for the U.S. industry on CNN as part of a larger discussion of industry’s emergency preparedness.
- NEI President and CEO Marvin Fertel spoke with New York Times reporter Tom Zeller on claims by the Natural Resources Defense Council and Union of Concerned Scientists that the NRC is a “captive” regulator. He described the NRC as an effective regulator and noted transparency in the U.S. regulatory process and improvements to better focus on safety over the past decade.
- NEI discussed the 25th anniversary of Chernobyl in the context of Fukushima with Forbes Magazine.
- Homeland Security Today magazine is focusing its July issue on challenges of critical infrastructure security, especially from earthquakes, tsunamis and other severe events. In an interview, NEI addressed the improvements over the last 10 years, including physical additions to plant security, additional personnel and training, shift drill exercises and NRC-graded exercises.
The Week Ahead:
- The NRC will meet at 9 a.m. EDT Tuesday, May 3, for a briefing on emergency preparedness. The meeting will be webcast.
- The House Energy and Commerce Committee’s subcommittees on energy and power and environment and the economy will conduct a joint hearing at 9:30 a.m. EDT on Wednesday, May 4, to examine the role of the NRC in America’s energy future. All of the commissioners are expected to testify.
UPDATE AS OF 5 P.M. EDT, WEDNESDAY, APRIL 27:
NEI has uploaded a new video to its YouTube channel. The video, “Health Physicist Explains U.S. Radiation Monitoring,” features Health Physics Society’s President Edward Maher who explains how the U.S. Environmental Protection Agency and U.S. Food and Drug Administration monitor radiation levels in the environment.
UPDATE AS OF 12 P.M. EDT, FRIDAY, APRIL 22:
Below is a round-up of noteworthy news that happened this week with regard to the Fukushima Daiichi nuclear plant and the U.S. nuclear industry’s response.
- Tokyo Electric Power Co. (TEPCO) released a roadmap to bring the Fukushima Daiichi nuclear plant to a stable condition.
- Priorities at Fukushima this week continue to be cooling the reactors and spent fuel pools, draining water from the turbine buildings and concrete structures that house piping to reduce radiation levels, and containing the spread of radioactive materials.
- Overall, site radiation dose rates are stabilizing. The most recent radiation readings reported at the plant site gates ranged from 5.7 millirem per hour to 2.6 millirem per hour.
- Japan’s government has expanded evacuation to selected areas outside the original 12.5-mile zone. Authorities also are barring entry into nine municipalities near the plant.
- TEPCO released a presentation on April 18 summarizing the impact of the earthquake and the current status of the plants.
- The U.S. Nuclear Regulatory Commission continues its inspections of nuclear plant sites to review post-Fukushima-related issues.
New NEI Products:
- Video on the future of nuclear energy, featuring Idaho National Laboratory Director John Grossenbacher.
- Video on the differences in health impacts between Fukushima and Chernobyl, featuring Barbara Hamrick, health physicist at the University of California’s Irvine Medical Center.
- Video putting the potential of health risks from Fukushima into perspective, also featuring Barbara Hamrick.
- An April 21 Associated Press article covered nuclear insurance and an April 19 story detailed early management of the accident.
- CNN on April 20 covered restricted access to the evacuation zone.
- A report on the results of a Washington Post-ABC poll released April 20 said that 53 percent of Americans believe nuclear power is safe, but the public opposes construction of new reactors by a 2-to-1 margin.
- An April 20 Associated Press article focused on projected Fukushima worker health problems.
- An April 19 New York Times article covered water management at the nuclear power plant site.
- A Wisconsin State Journal editorial warning that a retreat from nuclear energy is unwise.
The Week Ahead
- The U.S. Nuclear Regulatory Commission public meeting April 28 to discuss the agency’s response to events at the Fukushima, including station blackout issues.
UPDATE AS OF 11 A.M. EDT, THURSDAY, APRIL 21:
As workers continue to pump cooling water into the reactors and used fuel pools at the Fukushima Daiichi nuclear power plant, they also continue to deal with contaminated water at the site.
A particular problem has been the leakage of highly radioactive water on the turbine building side of reactor 2. Tokyo Electric Power Co. (TEPCO) workers this week completed injecting liquid glass and cement-based grout to seal a concrete enclosure outside the building. They also installed iron plates at the screen room of reactor 2 and silt fences in front of the screen rooms of reactors 1-4. TEPCO is placing sandbags in strategic locations around the site.
Workers also continued to pump water out of the reactor 2 turbine building into a tank at the on-site waste processing facility. This is a slow-moving process estimated to take 26 days. In all, TEPCO estimates that 67,500 tons of radioactive water has accumulated at the plant.
Robots detected high levels of radiation hazardous to humans over even a short amount of time in buildings for reactors 1 and 2. Reactor 3 also was surveyed, but radiation levels weren’t available. Cameras on the robots showed debris on the floors of the buildings that could hamper work after the radiation is controlled.
New Video Posted
NEI has uploaded a new video to its YouTube channel. The video, “INL Director Discusses the Future for Nuclear Energy in the United States,” features the Idaho National Laboratory’s Director John Grossenbacher, who explains that the United States should develop its energy policies based on an assessment of the current events at Japan’s Fukushima nuclear reactors and the costs and benefits of providing electricity through various energy sources.
UPDATE AS OF 5 P.M. EDT, MONDAY, APRIL 18:
Tokyo Electric Power Co. (TEPCO) estimates it will take up to nine months to stabilize the Fukushima Daiichi nuclear power plant. A plan released Sunday breaks the project into two steps, the first taking up to three months, the second up to six months more.
According to the company’s “Roadmap Towards Restoration,” TEPCO plans to:
- Fill the containment vessels of reactors 1 and 3 with enough water to cover the fuel in the reactors while it decides the best course of action to repair the damaged containment vessel of reactor 2. The goal is to lower the temperature of the water inside the reactors to below boiling.
- Install heat exchangers to help cool the reactors. TEPCO continues to inject water into the reactors to prevent overheating. TEPCO also continues to spray water onto the used fuel storage pools as needed.
- Use giant covers with filters to enclose the reactor buildings and control the release of radioactivity.
- Install additional water storage tanks and purification facilities to process the highly radioactive water that has accumulated in the plant buildings and nearby concrete enclosures. The decontaminated water then will be used to cool the reactors. Radioactive water that has accumulated in turbine room basements is hampering work to restore cooling operations.
- Expand monitoring of radiation in the 12.5-mile evacuation area and later decontaminate houses and soil.
TEPCO continues injection of nitrogen gas into the containment vessel of reactor 1 to stabilize the environment inside the reactor.
New Videos Posted
NEI has uploaded two new videos to its YouTube channel: “Health Physicist Explains the Differences in Health Impacts From Fukushima Versus Chernobyl” and “Health Physicist Says Fukushima Poses No Health Risk to Americans.” Both videos feature Barbara Hamrick, radiation safety officer and certified health physicist at the University of California’s Irvine Medical Center.
UPDATE AS OF 2 P.M. EDT, FRIDAY, APRIL 15:
NEI has uploaded a new video to its YouTube channel. The video, “INL Director Discusses Lessons Learned From TMI, Fukushima,” features the Idaho National Laboratory’s Director John Grossenbacher, who discusses how the U.S. nuclear industry has boosted its safety procedures as a result of the Three Mile Island (TMI) accident in 1979 and how the industry plans to use current events at Japan’s Fukushima nuclear plants to further enhance safety.
UPDATE AS OF 11 A.M. EDT, FRIDAY, APRIL 15:
Tokyo Electric Power Co. (TEPCO) is continuing to manage the transfer of large amounts of contaminated water from basements and tunnels at Fukushima Daiichi as it works to restore the plant’s cooling systems. On Friday TEPCO said the level of radioactive water was increasing in a tunnel at reactor 2 after an earlier drop. The company had on Wednesday finished transferring some 660 tons of water from the tunnel to a condenser in a turbine building, resulting in a drop of the water level in the tunnel by 8 centimeters. However, by Friday morning the level in the tunnel had returned to its previous level. TEPCO says there are at least 50,000 tons of contaminated water at the plant. It plans to use a waste-processing facility, makeshift storage tanks and a floating tank to store the radioactive water.
TEPCO also reports that radiation levels of Iodine-131 and Cesium-134 in water in so-called sub-drain pits have risen by up to 38 times during the past week.
The company is working to finish moving emergency diesel power generators and water injection pumps to higher ground and to bring in additional backup power trucks and fire engines as a precautionary measure. Work is also in progress to cross-connect external grid power lines to all four reactors.
The U.S. State Department has lifted its voluntary evacuation advisory for families of U.S. government employees in Tokyo and other Japanese cities, saying that while the situation remains serious, it is “dramatically different” now than it was on March 16, and health and safety risks are low for areas outside an 80-kilometer (50-mile) zone around the plant, which includes Tokyo. However, it has maintained its recommendation for U.S. citizens to avoid travel within the 50-mile zone.
TEPCO also reported on Friday it had conducted a 2-hour long unmanned helicopter flight over reactors 1 through 4 “to check the condition of the reactor buildings.” The helicopter is to fly again today. Video footage has not yet been released.
UPDATE AS OF 6:30 P.M. EDT, THURSDAY, APRIL 14:
NEI has uploaded a new video to its YouTube channel. The video, “INL Director Explains How the National Labs Are Assisting With Japan’s Nuclear Crisis,” features the Idaho National Laboratory’s Director John Grossenbacher, who discusses the types of nuclear expertise and capabilities that exist within the U.S. Department of Energy’s national labs to assist with the Japan nuclear crisis. He also explains how the labs will provide long-term research that will uncover lessons learned from the Fukushima nuclear plants.
UPDATE AS OF 11 A.M. EDT, THURSDAY, APRIL 14:
Tokyo Electric Power Co. (TEPCO) has moved highly contaminated water from a concrete enclosure outside reactor 2 at the Fukushima Daiichi nuclear power plant, the utility reported. TEPCO said the water is stored in the reactor’s condenser.
To help keep radioactive water from diffusing into the ocean near the plant, TEPCO has installed an underwater silt fence in front of the intake screen for reactors 3 and 4.
Radioactive water that has accumulated in turbine room basements is interfering with work to restore cooling operations at the site. TEPCO is completing preparations to transfer the contaminated water to the plant’s radioactive water processing facility and other temporary storage locations.
TEPCO continues to inject cooling water into reactors 1, 2 and 3 and to spray water as needed into the used fuel pools for reactors 1-4. TEPCO also continues injection of nitrogen gas into the containment vessel of reactor 1 to prevent the potential for an explosion of hydrogen that may be accumulating inside.
Workers continued Thursday to move emergency diesel generators to higher ground to keep them safe from aftershocks and tsunamis, the Japan Atomic Industrial Forum reported. An aftershock on Monday briefly disrupted electric power at the Daiichi plant, and a series of aftershocks has rattled the plant several times this week, causing no further damage. TEPCO also is rewiring the external power lines to avoid a total blackout.
UPDATE AS OF 10 A.M. EDT, WEDNESDAY, APRIL 13:
Workers at the Fukushima Daiichi nuclear power plant are pumping radioactive water from the concrete enclosure near reactor 2 into a turbine condenser. A series of aftershocks that rattled the area Tuesday has put the work behind schedule. Tokyo Electric Power Co. (TEPCO) is inspecting another storage facility on the site to determine if it can hold contaminated water from the basement of the reactor 2 turbine building. Radioactive water in the turbine buildings is hampering efforts to restore cooling operations at the plant.
TEPCO continues to inject cooling water into reactors 1, 2 and 3 and to spray water as needed into the used fuel pools for reactors 1-4. TEPCO also continues injection of nitrogen gas into the containment vessel of reactor 1 to prevent a possible explosion of hydrogen that may be accumulating inside.
UPDATE AS OF 6:30 P.M. EDT, TUESDAY, APRIL 12:
NEI has posted a new fact sheet, “Comparing Chernobyl and Fukushima.” The key facts show that although the events at the Fukushima nuclear plant and the Chernobyl accident are both at a level 7 according to the International Nuclear and Radiological Event Scale, the situations are starkly different because of different reactor designs and much less severe public health consequences at Fukushima.
UPDATE AS OF 11:30 A.M. EDT, TUESDAY, APRIL 12:
Tokyo Electric Power Co. (TEPCO) is planning to pump highly radioactive water from reactor 2 into a condenser, as the utility works to control radiation and restore cooling systems at the Fukushima Daiichi nuclear power plant.
TEPCO continues to inject cooling water into reactors 1, 2 and 3 and to spray water into the used fuel pools for reactors 1-4. TEPCO also continues injection of nitrogen gas into the containment vessel of reactor 1 to prevent a possible explosion of hydrogen that may be accumulating inside.
A fire that broke out early Tuesday at a distribution switchboard near the south water discharge channel for reactors 1-4 was extinguished without interruption of reactor cooling operations or the release of radioactivity, TEPCO said.
The crisis rating of the Fukushima Daiichi accident was raised from 5 to 7 on the seven-level International Nuclear and Radiological Event Scale by the Japan Nuclear and Industrial Safety Agency. The new level, the highest on the scale, designates Fukushima as a “major accident.” The new rating puts the Japanese incident on the same level as the 1986 Chernobyl accident—even though Japanese authorities estimate that radiation released at Fukushima is only 10 percent of the amount released from the Ukrainian plant.
Authorities said much of the high-level radiation leaked from reactor 2 on March 15 and 16, early in the accident. Abnormalities in the reactor’s suppression pool caused the radiation release, the Japan Nuclear Safety Commission said. Radiation continues to leak from the suppression pool, the commission said, but the volume has dropped considerably.
UPDATE AS OF 8:30 A.M. EDT, TUESDAY, APRIL 12:
Japan’s nuclear safety agency has raised the crisis level of the Fukushima Daiichi accident from 5 to 7 on the seven-level International Nuclear and Radiological Event Scale. The new rating puts the Japanese incident on the same level as the 1986 Chernobyl accident—even though Japanese authorities estimate that radiation released at Fukushima is only 10 percent of the amount released from the Ukrainian plant.
The new level designates Fukushima as a “major accident,” up from an “accident with wider consequences.” Level 7, the highest on the scale, describes an event with “a major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures,” according to the International Atomic Energy Agency, which sponsors the ratings.
For the new rating, the Japan Nuclear and Industrial Safety Agency combined the accidents at reactors 1, 2 and 3 as a single event. Previously, separate level 5 ratings had been applied to each reactor. The earlier level 3 rating (“serious incident”) still applies to reactor 4.
Japanese authorities may revise the INES rating at the power plant as more information becomes available.
UPDATE AS OF 2:30 P.M. EDT, MONDAY, APRIL 11:
NEI has uploaded a new video to its YouTube channel. The video, “Plutonium’s Role in a Nuclear Reactor,” features NEI’s Everett Redmond, director of nonproliferation and fuel cycle policy, who discusses where plutonium comes from and how it is used in a nuclear reactor.
UPDATE AS OF 11:30 A.M. EDT, MONDAY, APRIL 11:
No damage to Japan’s nuclear power plants was reported today after another strong aftershock hit the northeast coast. The temblor, measured at magnitude 6.6 by the U.S. Geological Survey, rocked the country one month after the magnitude 9.0 earthquake and tsunami struck March 11, damaging the Fukushima Daiichi nuclear power plant. A magnitude 7.1 aftershock rattled Japan April 7.
The Monday earthquake prompted the temporary evacuation of workers at the plant and interrupted the offsite electric power supply for less than an hour. Injection of cooling water to reactors 1, 2, and 3 resumed within an hour. Officials reported no new damage or increased radiation levels. Workers continued to spray water into the spent fuel pools of reactors 1-4 as needed.
As an additional safety measure, Tokyo Electric Power Co. (TEPCO) has brought additional diesel generators to the site as a backup in case offsite power is disabled.
Preparations are being made to transfer highly radioactive water from reactor 2 to a water storage tank. Workers are inspecting the tank to ensure there will be no leaks.
TEPCO is injecting nitrogen gas into the reactor 1 containment vessel to reduce the possibility of a hydrogen explosion. TEPCO plans to inject nitrogen into the containment vessels of reactors 2 and 3, the Japan Atomic Industrial Forum reported.
TEPCO used a drone helicopter to take aerial pictures of reactor buildings that are highly contaminated. TEPCO also is using remote-controlled heavy equipment to remove radioactive debris.
Japanese authorities announced that residents of some municipalities outside the 12.5-mile radius evacuation zone will be relocated to reduce long-term radiation exposure. Radiation can accumulate in some places based on weather and geographical factors. The relocation orders will apply to areas where there is a possibility of residents receiving a dose of 2,000 millirem over the course of a year.
UPDATE AS OF 11:30 A.M. EDT, SUNDAY, APRIL 10:
Management of water continues to be a top priority at Tokyo Electric Power Co.’s Fukushima Daiichi nuclear power plant.
TEPCO has begun to install steel sheets and a silt barrier at the intake structure for reactor 2 to prevent further spreading of radioactive water that is leaking from the power plant, Kyodo news service has reported. Plans are under way to install similar barriers at other locations near the plant in an effort to contain contaminated water within the plant’s bay. Last week, TEPCO used a sealant to block a leak from a concrete enclosure near reactor 2.
Meanwhile, 60,000 tons of contaminated water must be removed from the reactor 1, 2, and 3 turbine buildings and nearby underground enclosures, the International Atomic Energy Agency reported. The water will be pumped into the condensers of each reactor and into a radioactive water storage tank. TEPCO made room in the tank by discharging low-level radioactive water into the Pacific Ocean. TEPCO also has ordered temporary storage tanks for the site.
Injection of cooling water into reactors 1, 2 and 3 continues. Workers are spraying water into the spent fuel pools for reactors 1-4 as needed. TEPCO also continues to inject nitrogen gas into the primary containment of reactor 1. The nitrogen will prevent possible ignition of hydrogen that may be accumulating in the containment.
The utility is now using remote-controlled bulldozers and power shovels to remove radioactive rubble from around the plant. Operators are using cameras on the equipment and elsewhere on the site to control the equipment from hundreds of yards away. The rubble will be stored at the plant site.
The Japan education ministry is expected this week to release radiation exposure safety guidelines for school children in areas outside the evacuation zone surrounding the power plant, the Japan Atomic Industrial Forum reported. The guidelines will require schools to suspend classes, stop outdoor lessons, or ensure students wear face masks if radiation surpasses certain levels.
UPDATE AS OF 11:30 A.M. EDT, SATURDAY, APRIL 9:
Tokyo Electric Power Co. (TEPCO) has increased its efforts to remove highly radioactive water that is slowing restoration of reactor cooling systems at the Fukushima Daiichi nuclear power plant, the Japan Atomic Industrial Forum reports.
For the last several days, TEPCO workers have been discharging low-level radioactive water from a storage tank to the Pacific Ocean to make room for highly contaminated water that has accumulated in the basements of reactor turbine buildings. After the discharge is complete, which is expected by Sunday, and after the storage tank has been inspected for possible earthquake damage, workers can begin to pump the radioactive water out of the turbine buildings.
Earlier this week, TEPCO sealed a crack in a concrete enclosure near reactor 2 that was allowing highly radioactive water to leak into the ocean. Since then, the utility has reported the water level in the enclosure has risen, but said it is not expected to overflow from the enclosure. TEPCO has not identified the source of the contaminated water.
Workers continue to use backup pumps to inject cooling water into reactors 1, 2 and 3 at the Fukushima Daiichi site. Spraying water onto the used fuel pools of reactors 1-4 continues on an as-needed basis. TEPCO also continues to inject nitrogen gas into the primary containment of reactor 1. The nitrogen will prevent possible ignition of hydrogen that may be accumulating in the containment.
TEPCO is preparing to fly a small, unmanned helicopter over the plant to take infrared photos of areas that have been out of reach. The photos may help the company plan its restoration work.
Overall, dose rates around the site continue to decline.
UPDATE AS OF 11:30 A.M. EDT, FRIDAY, APRIL 8:
No nuclear power plants were seriously damaged in the heavy aftershock that rattled northeastern Japan Thursday, the International Atomic Energy Agency reported. The epicenter of the 7.1 magnitude earthquake was 12.5 miles from the Onagawa nuclear power plant and about 75 miles from the Fukushima Daiichi site, where engineers are working to restore fuel cooling capabilities that were lost in the original March 11 temblor and tsunami.
At Fukushima Daiichi, the injection of cooling water into the reactor pressure vessels of reactors 1, 2 and 3 continued Friday, along with injection of nitrogen gas into the containment vessel of reactor 1. The nitrogen will prevent possible ignition of hydrogen that may be accumulating in the containment. Tokyo Electric Power Co. is continuing the discharge of low-level radioactive water from a waste storage tank into the Pacific Ocean to make room for highly radioactive water pooled in the basement of the reactor 2 turbine building.
Isolated spikes in radiation inside reactor 1 containment have been associated with possible fuel movement during the April 7 aftershock, but radiation dose rates elsewhere at the site continue to decline.
The government lifted restrictions on shipments of raw milk and some produce from municipalities near Fukushima Daiichi. An official said tests show the food is safe to consume.
The aftershock of April 7 caused minimal, if any, disruption at other nuclear power plants.
All reactors have been shut down since the March 11 earthquake. There have been no changes in the radiation readings at on-site monitoring posts.
All reactors have been safely shut down since the March 11 earthquake. Reactor cooling operations continue with power from the electric grid. A small amount of water was spilled from the spent fuel storage pools of all three reactors. Workers also found water leaks in several locations at the plant. Cooling for a spent fuel pool was lost briefly. There was no change in off-site radiation levels.
The plant has been shut down since the March 11 earthquake. No abnormalities have been observed.
The plant was shut down for maintenance at the time of the aftershock. Fuel had been removed from the reactor core and stored in the spent fuel pool. Off-site power was lost in the aftershock, and the plant operated for a few hours on backup generators. Later, off-site power was restored.
Reactors 1 and 2 were in operation at the time of the aftershock. Hokkaido Electric Power Co. reduced the generating power to 90 percent of capacity.
Rokkasho Reprocessing Plant
Off-site electric power was lost in the aftershock. Backup power supply to the site is operating the cooling systems.
UPDATE AS OF 1:00 P.M. EDT, THURSDAY, APRIL 7:
Tokyo Electric Power Co. continued to inject cooling water into reactors 1, 2 and 3 at the Fukushima Daiichi nuclear power plant, despite a 7.1 magnitude aftershock that hit 70 miles north of the plant.
The temblor, the largest aftershock since the 9.0 magnitude earthquake on March 11, hit at 11:32 pm JST today off the northeast coast. The Japanese government issued a tsunami warning after the earthquake, but lifted it about 90 minutes later.
Three nuclear power plants—Fukushima Daini, Fukushima Daiichi and Onagawa—were shaken, but officials reported no new damage and no injuries to employees. Two of the three electric power lines that supply the Onagawa plant were offline, but normal operations continued with the remaining power line to maintain reactor cooling systems. The plant had been safely shut down since March 11.
Seawater radiation levels, while still significantly higher than government safety limits, have decreased near the power plant since TEPCO blocked a leak of highly radioactive water into the ocean. TEPCO said it is too early to credit stopping the leak with the decline.
Workers continued to inject nitrogen gas into the containment vessel of reactor 1, a process that began Wednesday. Inert nitrogen gas is used in reactor containment vessels to stabilize the atmosphere. The nitrogen injection is to prevent possible ignition of the hydrogen that is believed to be accumulating inside the reactor 1 containment. It is expected to take six days to complete the process. Spraying water onto the used fuel storage pools at reactors 1-4 was interrupted briefly because of the earthquake.
TEPCO continued its controlled discharge of low-level radioactive water into the Pacific Ocean to make room in storage tanks for more highly contaminated water on the site. The highly radioactive water in turbine building basements is hampering efforts to restore cooling systems, particularly for reactor 2, where the radiation is highest. Before the highly radioactive water is pumped into the wastewater storage tank, the facility must be inspected for damage, the Japan Atomic Industrial Forum reported. Inspection could take up to a week.
The Japanese government is evaluating possible evacuation of some residents from areas within 12.5 to 18.5 miles of the Fukushima Daiichi site. Residents in the 12.5-mile zone were evacuated early in the emergency. Those within the outer area have been advised to stay indoors. The additional evacuation would be from areas where radiation has accumulated since March 11.
UPDATE AS OF 11:30 A.M. EDT, THURSDAY, APRIL 7:
A 7.1 magnitude aftershock in northeastern Japan today caused no damage to nuclear power plants in the area, the Nuclear and Industrial Safety Agency reported. Plant employees at the Fukushima Daiichi, Fukushima Daini and Onagawa plants were evacuated for safety after the temblor, which struck at 11:32 pm JST.
Two of the three electric power lines that supply the Onagawa site were down, officials said, but operations at the plant’s three reactors were continuing as normal with power from the remaining line. There was no change in radiation levels near the plant.
The reactors at the three sites had been shut down since the magnitude 9.0 earthquake on March 11.
There were no damages reported at the Fukushima Daiichi and Daini plants. At Daiichi, where engineers have been working to cool reactors since the March 11 earthquake, fresh water injection continued.
UPDATE AS OF 11:30 A.M. EDT, WEDNESDAY, APRIL 6:
Tokyo Electric Power Co. (TEPCO) today began injecting nitrogen into the containment vessel of reactor 1 at the Fukushima Daiichi nuclear power plant. Nitrogen, an inert gas, is used in reactor containment vessels to stabilize the atmosphere and prevent ignition of the hydrogen that is believed to be accumulating inside the containment. The injection will proceed slowly, at 10 percent of the normal rate. It is expected to take six days to complete the process.
TEPCO has stopped a leak of highly radioactive water from the site into the Pacific Ocean. TEPCO had been trying various means to plug the leak in a concrete enclosure that carries electric cables since it was discovered Saturday. Pouring concrete and later an absorbent polymer into the enclosure were unsuccessful.
On Monday, workers injected a colored liquid tracer into the system of enclosures to determine the flow path of the water. It showed that the radioactive water may be leaking from a cracked pipe, and then seeping through gravel into the concrete enclosure. Additional testing showed leakage from the crack in the enclosure into the ocean.
Beginning yesterday, TEPCO injected approximately 1,600 gallons of liquid glass into the system, which stanched the flow of water. TEPCO is considering injecting more liquid glass into the area as a preventive measure.
Workers continue to inject cooling water into reactors 1, 2 and 3 and to the used fuel storage pools at reactors 1-4. Radioactive water in the turbine buildings continues to hinder efforts to fully restore cooling functions.
Some residents of the 20-kilometer (12.5-mile) evacuation zone around Fukushima Daiichi may be permitted brief visits to retrieve personal items from their homes. The Japanese government is analyzing radiation data and is expected to draft a plan for the visits.
UPDATE AS OF 11:30 A.M. EDT, TUESDAY, APRIL 5:
Tokyo Electric Power Co. (TEPCO) continued efforts Tuesday to stop the flow of radioactive water from the Fukushima Daiichi nuclear power plant into the Pacific Ocean.
On Saturday, workers found a crack in a concrete enclosure used to carry electric cables near reactor 2. Since then, TEPCO has attempted to seal the crack with concrete and with an absorbent polymer, with no success.
A colored liquid tracer was injected into the system of enclosures Monday to determine the flow path of the water. The test showed that the radioactive water may be leaking from a cracked pipe, and then seeping through gravel into the concrete enclosure. Today, TEPCO is taking a new approach: sealing gravel under the enclosure with liquid glass. TEPCO has not yet announced the outcome.
To free up storage space for highly radioactive water in a waste disposal tank, TEPCO has begun to discharge 11,500 tons of low-level radioactive water into the ocean. The utility will use the tank to hold highly radioactive water that has accumulated in the basements of the reactor 1, 2 and 3 turbine buildings.
Small fish caught in waters south of Fukushima prefecture have been found to contain radioactive cesium. The Ibaraki Prefecture government said 14 picocuries of radioactive cesium was detected in one kilogram of sand lances. The acceptable limit is 13.5 picocuries per kilogram. This is the first time radioactive cesium has been found in fish at a level above the government limit.
Workers continue to inject cooling water into reactors 1, 2 and 3. In addition, spent fuel pools for reactors 1-4 are sprayed with fresh water as needed to keep them cool. (See NEI’s video, “Spent Fuel Storage in Pools at Nuclear Energy Plants,” for more information about how these pools work.)
NRC Chairman Jaczko: U.S. Nuclear Plants Are Safe
Events in Japan will inform future activities of the U.S. Nuclear Regulatory Commission, its chairman said. “We already have begun enhancing inspection activities through temporary instructions to our inspection staff, including the resident inspectors and the inspectors in our four regional offices,” Gregory Jaczko told participants in a regular international review of nuclear safety, now convened in Vienna.
He said the NRC has asked licensees to verify that their abilities to mitigate conditions due to severe accidents—including the loss of major operational and safety systems—are in effect and operational, including a total loss of electric power, flooding, and damage from seismic events.
The NRC is “confident about the safety of U.S. nuclear power plants,” Jaczko said.
New Video on Emergency Preparedness
NEI has uploaded a new video to its YouTube channel: “Emergency Planning and Coordination at Nuclear Energy Plants.” The video features NEI’s Director of Emergency Preparedness Sue Perkins-Grew who explains emergency planning zones and how state and local authorities coordinate their responses during an emergency.
UPDATE AS OF 11:30 A.M. EDT, MONDAY, APRIL 4:
Workers at the Fukushima Daiichi nuclear power plant continued searching Monday for sources of contaminated water leaking from the site into the ocean.
Attempts to seal a crack in a concrete enclosure for cabling in reactor 2 are ongoing after initial efforts failed. Tokyo Electric Power Co. (TEPCO) injected a color tracer into the enclosure in an effort to track the flow of water. That test confirmed the radioactive water is from multiple sources. TEPCO is planning to install underwater silt barriers near the intake for reactor 2 to help contain the contaminated water.
Japan’s Nuclear and Industrial Safety Agency (NISA) and Nuclear Safety Commission both said it will take several months to restore permanent core cooling for the damaged reactors. NISA said it will take that amount of time to remove contaminated water from the turbine buildings and restore damaged plant equipment.
To free up storage space for highly radioactive water in a waste disposal tank, TEPCO is seeking approval to discharge 11,500 tons of low-level radioactive water into the ocean. The utility said the radiation level in the water to be discharged is very low. TEPCO estimated that someone eating fish and seaweed from the adjacent water every day for a year would receive a total exposure of 60 millirem, less than a quarter of the average annual exposure from natural radiation.
Workers continue to inject cooling water into reactors 1, 2 and 3. In addition, spent fuel pools for reactors 1-4 are sprayed with fresh water as needed to keep them cool.
Radiation dose rates at the Daiichi site continue to fall. Recent readings showed 12.4 millirem per hour at the main gate, 7.4 millirem per hour at the west gate and 78 millirem per hour on the side of the administration building facing the reactors.
Majority of Americans Think Nuclear Power Is Safe, Poll Shows
A Gallup survey shows that most Americans believe nuclear power is safe. In a poll conducted March 25-27, 58 percent of Americans said they think nuclear power plants in the United States are safe; 36 percent said they are not.
A Harris poll conducted March 23-25 found that 29 percent of Americans consider nuclear power plants “very safe,” with another 34 percent saying they are “somewhat safe.”
UPDATE AS OF 8:15 A.M. EDT, MONDAY, APRIL 4:
New Fact Sheet Describes Vital Modifications and Upgrades to U.S. Reactors
NEI has created a new fact sheet, “U.S. Nuclear Power Plants Reconfirming Safety, Response Programs in Light of Japan Situation,” which gives a detailed analysis of steps the U.S. nuclear energy industry is taking to ensure safety, including federal regulation, plant modification and upgrades, enhanced emergency readiness and response, and severe accident management. (The graphic from page 3 of the fact sheet is available here.
UPDATE AS OF 3 P.M. EDT, SUNDAY, APRIL 3:
Tokyo Electric Power planned Sunday to inject water-absorbing polymer into a cracked concrete enclosure near the reactor 2 water intake at the Fukushima Daiichi nuclear power plant in an effort to stop radioactive water from leaking into the ocean. Yesterday, pouring concrete into the concrete enclosure, which carries electric cables, failed to seal the crack.
TEPCO said it had not found water leaking from the concrete enclosures at other reactors, the Japan Atomic Industrial Forum reported.
Following detection of the reactor 2 leak, the power company began testing radiation levels in sea water 15 kilometers (about 9.5 miles) from the facility.
A U.S. Navy barge has begun supplying fresh water as injection continues to cool reactors 1, 2, and 3. TEPCO is using a motor-driven pump powered by an off-site transmission line. A second barge with more fresh water has arrived at the site. Electric power has been restored to lighting in the turbine buildings of reactors 1, 2, and 3.
After consultations with nuclear experts from the United States, TEPCO has begun to measure radiation levels inside the nuclear power plant’s 20-kilometer (12.5 mile) evacuation zone. Measurements have been taken routinely outside the zone, but TEPCO has been reluctant to conduct tests closer to the plant because of anticipated radiation exposure to workers taking those measurements.
Radiation levels off site and at the site boundary are generally decreasing, although localized areas with elevated levels are being identified for further analysis. Protective action recommendations for food and water are gradually being lifted in many locations, but some remain pending further analysis.
The government is looking carefully at how and when to allow evacuees to return to their homes. The situation remains difficult for evacuees, especially the elderly and ill among them, but the government is escalating efforts to accommodate those who have evacuated.
The government is monitoring children up to 15 years old in some prefectures for possible iodine-131 exposure. Based on preliminary results, iodine-131 has not been found at levels that exceed action levels, and in many areas there has been no exposure.
Missing Workers Found
Tokyo Electric Power Co. has confirmed that two company employees who had been missing since the tsunami occurred on March 11 were found dead March 30 in the basement of the turbine building of reactor 4.
UPDATE AS OF 12 P.M. EDT, SATURDAY, APRIL 2:
Recovery efforts continue at the Fukushima Daiichi nuclear plant in Japan, as aid pours in from the international nuclear community in the form of technical expertise, protective equipment for workers, storage tanks for contaminated water and other measures.
Today, Tokyo Electric Power Co. (TEPCO) said it has identified one likely source of contaminated water reaching the Pacific Ocean, accounting for some of the radiation readings in seawater samples taken over the past several days. The crack is in a two-meter-deep concrete “pit,” or trench, that contains power cables near the reactor 2 water intake. Water measuring between 10 and 20 centimeters deep was found in the pit with radiation levels of more than 1,000 milliSieverts per hour. TEPCO plans to pour concrete to patch the crack while continuing to search for other potential leak paths.
The Nuclear Industrial and Safety Agency says iodine-131 will be diluted in seawater and does not pose a threat to the public. Additionally, iodine-131 has a short half-life—about eight days—and will decay to harmless levels fairly quickly. (See Health Impacts of Iodine-131 to learn more about the health impacts of iodine-131.)
The Japan Atomic Industrial Forum said TEPCO is obtaining a “massive, hollow floating platform” from Shizuoka City and will use it to store contaminated water from the Fukushima site. The float can store up to 18,000 tons of water. Meanwhile TEPCO and the Japanese government are working to identify safe methods for transporting and storing contaminated water.
NRC Forms Task Force to Review U.S. Safety Measures
The U.S. Nuclear Regulatory Commission announced April 1 that it has formed a task force to identify any potential near-term actions that affect U.S. nuclear power plants, including their used fuel pools. This is part of the NRC’s 90-day review of U.S. safety measures in light of what is known to date about the March 11 earthquake and tsunami. The review will encompass station blackout (loss of all offsite electrical power for a reactor), external events that would lead to a prolonged loss of cooling, plant capabilities for preventing or dealing with such circumstances and emergency preparedness. The task force will provide status reports in public meetings May 12 and June 16 and recommendations at a July 19 public meeting.
UPDATE AS OF 12:30 P.M. EDT, FRIDAY, APRIL 1:
Japan’s nuclear safety agency has reprimanded Tokyo Electric Power Co. for not providing radiation monitors to all emergency workers at the Fukushima Daiichi nuclear power plant.
Each worker is supposed to have an individual radiation monitor, but some emergency teams have had to share monitors, the Japan Atomic Industrial Forum reported. TEPCO said that low-priority work will be suspended if employees do not have monitors.
TEPCO said that only 320 of the 5,000 radiation monitors were available after the earthquake and tsunami, JAIF said.
Radiation Found in Beef
Radiation that exceeds safety standards has been found in beef in Fukushima and three neighboring prefectures, JAIF reported. Radiation also was found in spinach and other vegetables grown in the area. Japan’s health ministry said the beef and vegetables have not been shipped and are not on the market.
A U.S. Navy barge containing freshwater to cool the reactors and used fuel pools at the Daiichi site has been towed to the pier. It will be connected to the pumps with hoses.
Meanwhile, injection of freshwater continues at reactors 1-3 and workers continue to spray freshwater on the used fuel pools for reactors 1-4.
TEPCO is evaluating the use of a synthetic resin that would be sprayed over debris at the site to prevent the spread of radioactive dust.
Additional equipment, including the biggest concrete pump in the world, is being provided by U.S. companies. The pump’s 70-meter boom can be controlled remotely. It has been in use at the Savannah River Site, helping build a U.S. government mixed oxide nuclear fuel plant. Concrete pumps are already in use at the site to assist with spraying water into the used fuel pools.