Nuclear Energy Institute Post
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.
The Tokyo Fire Department sprayed cooling water into the reactor 3 used fuel pool for about 4.5 hours, ending early Monday morning. At reactor 4, Japan’s Self-Defense Force sprayed water into the pool for about two hours. Overall, 13 fire engines have been used in the spraying. Efforts to spray water into the used fuel pools at reactors 3 and 4 reactor buildings and used fuel pools was stopped on Monday while TEPCO assessed the effectiveness of these efforts.
Workers were evacuated from the area around reactors 2 and 3 Monday when smoke was observed coming from the secondary containment buildings.
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 10:00 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.
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.
UPDATE AS OF 10:00 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 onsite 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 09:00 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 8:00 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 to 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 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 fire-fighting 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 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.M. 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 10:00 A.M. EDT.
UPDATE AS OF 5:00 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."
Obama said "our nuclear plants have undergone exhaustive study and have been declared safe for any number of contingencies." 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 9:00 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 resumed efforts to spray water into the used fuel pool at the damaged reactor 4.
TEPCO also continues efforts to restore offsite power to the plant, with up to 40 workers seeking to restore electricity to essential plant systems by Thursday morning, March 17.
UPDATE AS OF 9:00 P.M. EDT, TUESDAY, MARCH 15:
At 5:45 am, March 16, Japan Standard Time (4:45 pm 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 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.
NUCLEAR ENERGY INDUSTRY WEB UPDATE AS OF 2:15 P.M. EDT, TUESDAY, MARCH 15: