Miyagi Kashiwazaki Kariwa Nuclear
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16/07/07, Nuclear scare after Japan quake, Source.
18/07/07, Kashiwazaki Kariwa nuclear units shutdown on earthquake, Source.
18/07/07, Japanese Nuclear Power Company Admits Leak Caused by Earthquake Is Bigger Than First Reported, Source.
16/07/07, Nuclear scare after Japan quake, (Back).
Clouds of smoke poured from the Kashiwazaki nuclear power plant
A strong earthquake in central Japan has damaged a large nuclear power plant causing a leak of radioactive material, officials at the plant have said.
A small amount of water containing radioactive substances leaked into the sea, officials said, and a fire broke out at the plant in Kashiwazaki. At least seven people were killed and hundreds injured in the earthquake.
Several hours later a second earthquake of magnitude 6.6 struck in the sea off Kyoto in western Japan. Tokyo Electric Power Company said the small amount of radioactive material that leaked into the sea posed no environmental risk. Reactors at the plant automatically shut during the magnitude 6.8 quake.
'Vertical jolt'
The seven deaths occurred in the city of Kashiwazaki. Four women and three men - all in their 70s and 80s - died from injuries sustained in the earthquake, officials said. Several hundred homes and businesses in Niigata prefecture were destroyed, roads were cracked and several landslides buried roads.
More than 800 people were reported injured, most with broken bones, cuts and abrasions from collapsing buildings and falling objects. "First there was a sharp vertical jolt and then it shook sideways for a long time and I couldn't stand up," said Kashiwazaki teacher Harumi Mikami, who was at her school when the earthquake struck at 1013 (0113 GMT).
"Tall shelves fell over and things flew around," she told Reuters news agency.
More than 7,000 people were evacuated from their homes as aftershocks of up to magnitude 5.8 shook the area. No damage from the second earthquake deep under the sea off Kyoto was reported but Tokyo residents said they felt buildings shake.
Safety fears
Japanese Prime Minister Shinzo Abe broke off from election campaigning to visit Kashiwazaki. He promised to "make every effort towards rescue and also to restore services such as gas and electricity".
The safety of Japan's nuclear installations, which supply much of Japan's power, has come under the spotlight in recent years after a string of accidents and mishaps.
Japan lies in one of the world's most earthquake-prone regions and the ability of some reactors to withstand a strong tremor has been questioned. Three years ago an earthquake in the Niigata area killed 65 people. In 1995, a magnitude 7.3 tremor hit the city of Kobe, killing more than 6,400 people.
18/07/07, Kashiwazaki Kariwa nuclear units shutdown on earthquake, (Back).
An earthquake of magnitude 6.8 struck Japan's Niigata prefecture on 16 July. Four nuclear power reactors at Kashiwazaki Kariwa shut down automatically, while one of them suffered a short-lived transformer fire and a small amount of water spilled from a used nuclear fuel cooling pool.
The earthquake, centred about 250 km northwest of Tokyo, hit at around 10.13 am, injuring more than 1000 people while destroying 300 buildings. Many roads were cracked, a temple roof collapsed and 35,000 people lost their water supply. Nine were killed.
At the Kashiwazaki Kariwa nuclear power plant, three of seven reactors - units 3, 4 and 7 - were in operation. Those reactors shut down safely as tremors began. Unit 2 was in the process of starting operation, and all systems shut down automatically as well.
Units 1, 5 and 6 were not operating as periodic inspections were being carried out. The tremors caused 1.2 cubic meters of water to spill from the used nuclear fuel cooling pond of unit 6. Plant owners Tokyo Electric Power Company (Tepco) said the water would contain 90 kBq of radioactivity, and had drained from the plant building to the sea in accordance with environmental regulations. The cooling pond itself was undamaged.
There was also a fire in the transformer of unit 3 following the earthquake. Tepco said this had been safely extinguished by 12.10 pm.
Transformers are used in all types of power station. As part of the system connecting the power unit's generator to the transmission grid, they step up the voltage of the electricity generated by the plant for transmission of energy over great distances without high losses. They are large oil-cooled components which deal with very high energy loads. As such they are located in designated and separated area of the plant and provided with ad-hoc monitoring systems, back-up units and fire protection.
In addition, Tepco said hundreds of drums of solid low-level radioactive waste (LLW) in the plant's solid waste storage facility fell from position. The lids of dozens of these were found open. LLW is typically composed of paper, filters, lightly-contaminated clothing and tools. Shigenori Makino of Tepco told World Nuclear News that the LLW drums in the facility contained either ash resulting from the incineration of flammable LLW items, the flammable items prior to incineration, or inflammable items as-is.
Tepco is currently inspecting all seven nuclear power units at the plant to assess what damage, if any, the earthquake may have caused and the exact reason for the transformer failure.
The earthquake was the biggest to affect the region since one of magnitude 6.8 in 2004. At that time no damage was recorded to the Kashiwazaki Kariwa plant.
18/07/07, Japanese Nuclear Power Company Admits Leak Caused by Earthquake Is Bigger Than First Reported, (Back).
KASHIWAZAKI, Japan — The operator of an earthquake-ravaged nuclear plant said Wednesday a radioactive leak from the plant was 50 percent bigger than first reported two days ago. The mayor ordered the facility closed until its safety could be confirmed.
Tokyo Electric Power Co. also said about 400 barrels containing low-level radioactive waste at the Kashiwazaki-Kariwa nuclear plant were knocked over, and the lids had come off 40 of them, as a result of Monday's deadly 6.8-magnitude quake. The announcement revised the company's earlier estimate of 100 tipped barrels.
"We made a mistake in calculating the amount that leaked into the ocean. We apologize and make correction," Tokyo Electric said in a statement. Spokesman Jun Oshima said the amount of radioactive water that leaked into the Sea of Japan was still "one-billionth of Japan's legal limit."
Tokyo Electric spokesman Tsutomu Uehara said no radiation has been detected outside the nuclear plant.
Japanese automakers, meanwhile, called production halts Wednesday at factories because of quake damage at a major parts supplier. Production was scaled back at Toyota Motor Corp., Nissan Motor Co. Mitsubishi Motors Corp. and Fuji Heavy Industries.
Toyota, Japan's No. 1 automaker, will stop production lines at a dozen factories centered in central Aichi prefecture Thursday afternoon and Friday. The shutdown was due to the temporary closure of Riken Corp.'s plant at Kashiwazaki, near the epicenter of Monday's quake.
Toyota will assess the situation at Riken, supplier of key transmission and engine parts, before deciding whether to resume production Monday, he said.
Repair workers on Wednesday climbed over the Kashiwazaki-Kariwa's three-story transformer building, which was charred from top to bottom in a fire Monday.
A tour given to Japan's Communist Party chief, Kazuo Shii, and reporters revealed widespread damage across the sprawling compound, including large cracks in roads, toppled concrete fences and buckled sidewalks.
"This is unforgivable," Shii told TEPCO Deputy Superintendent Masakazu Minamidate. "You say there's no leak before you really know. ... The delay in information was especially inexcusable."
TEPCO President Tsunehisa Katsumata toured the site earlier, declaring it "a mess" and apologizing for "all the worry and trouble we have caused."
"We will conduct an investigation from the ground up. But I think fundamentally we have confirmed that our safety measures worked," he said.
Hiroshi Aida, mayor of Kashiwazaki, a city near the epicenter that is home to the plant and 93,500 people, ordered operations at the plant halted Wednesday for "safety reasons."
The malfunctions and a delay in reporting them fueled concerns about the safety of Japan's 55 nuclear reactors, which have suffered a string of accidents and cover-ups. Nuclear power plants around Japan were ordered to conduct inspections.
Adding to the urgency of any investigation was new data from quake aftershocks that suggested a fault line may run underneath the mammoth power plant.
The Kashiwazaki-Kariwa plant, located 135 miles northwest of Tokyo, has been plagued with mishaps. In 2001, a radioactive leak was found in the turbine room of one reactor. It is the world's largest nuclear plant in power output capacity.
Signs of problems after the quake Monday came first not from the officials, but in a plume of smoke after the quake triggered a small fire at an electrical transformer. Twelve hours later, the company announced the quake also caused a leak of about 315 gallons of water containing radioactive material.
Later Tuesday, it said 50 cases of "malfunctioning and trouble" had been found. Four of the plant's seven reactors were running at the time of the quake, and they were all shut down automatically by a safety mechanism.
Meanwhile, TEPCO spokesman Hiroshi Itagaki said that information accumulated by studying aftershocks shows that a fault line stretches under the ocean near the coast, which is not far from the plant. He declined to say how close to the plant the fault might come.
Osamu Kamigaichi, an official at Japan's Meteorological Agency, which monitors earthquakes, said it was possible the fault line stretched to underneath the plant grounds.
Across the town, more than 8,000 residents hunkered down for their second night in shelters. Late Wednesday, police discovered a 76-year-old man crushed to death under a temple in Kashiwazaki, bringing the quake's fatalities to 10.
For residents, thousands of whom work at the plant, the controversy over its safety compounded already severe problems, which included heavy rains and the threat of landslides, water and power outages.
"Whenever there is an earthquake, the first thing we worry about is the nuclear plant. I worry about whether there will be a fire or something," said Kiyokazu Tsunajima, a tailor who sat outside with his family, afraid an aftershock might collapse his damaged house.
The area around Kashiwazaki was hit by an earthquake three years ago that killed 67 people, but the plant suffered no damage.
The plant's safety record and its proximity to a fault line prompted residents to file lawsuits claiming the government had failed to conduct sufficient safety reviews when it approved construction of the plant in the 1970s. But in 2005, a Tokyo court threw out a lawsuit filed by 33 residents, saying there was no error in the government safety reviews.
(Back)
18/07/07, Kashiwazaki Kariwa nuclear units shutdown on earthquake, Source.
18/07/07, Japanese Nuclear Power Company Admits Leak Caused by Earthquake Is Bigger Than First Reported, Source.
16/07/07, Nuclear scare after Japan quake, (Back).
Clouds of smoke poured from the Kashiwazaki nuclear power plant
A strong earthquake in central Japan has damaged a large nuclear power plant causing a leak of radioactive material, officials at the plant have said.
A small amount of water containing radioactive substances leaked into the sea, officials said, and a fire broke out at the plant in Kashiwazaki. At least seven people were killed and hundreds injured in the earthquake.
Several hours later a second earthquake of magnitude 6.6 struck in the sea off Kyoto in western Japan. Tokyo Electric Power Company said the small amount of radioactive material that leaked into the sea posed no environmental risk. Reactors at the plant automatically shut during the magnitude 6.8 quake.
'Vertical jolt'
The seven deaths occurred in the city of Kashiwazaki. Four women and three men - all in their 70s and 80s - died from injuries sustained in the earthquake, officials said. Several hundred homes and businesses in Niigata prefecture were destroyed, roads were cracked and several landslides buried roads.
More than 800 people were reported injured, most with broken bones, cuts and abrasions from collapsing buildings and falling objects. "First there was a sharp vertical jolt and then it shook sideways for a long time and I couldn't stand up," said Kashiwazaki teacher Harumi Mikami, who was at her school when the earthquake struck at 1013 (0113 GMT).
"Tall shelves fell over and things flew around," she told Reuters news agency.
More than 7,000 people were evacuated from their homes as aftershocks of up to magnitude 5.8 shook the area. No damage from the second earthquake deep under the sea off Kyoto was reported but Tokyo residents said they felt buildings shake.
Safety fears
Japanese Prime Minister Shinzo Abe broke off from election campaigning to visit Kashiwazaki. He promised to "make every effort towards rescue and also to restore services such as gas and electricity".
The safety of Japan's nuclear installations, which supply much of Japan's power, has come under the spotlight in recent years after a string of accidents and mishaps.
Japan lies in one of the world's most earthquake-prone regions and the ability of some reactors to withstand a strong tremor has been questioned. Three years ago an earthquake in the Niigata area killed 65 people. In 1995, a magnitude 7.3 tremor hit the city of Kobe, killing more than 6,400 people.
18/07/07, Kashiwazaki Kariwa nuclear units shutdown on earthquake, (Back).
An earthquake of magnitude 6.8 struck Japan's Niigata prefecture on 16 July. Four nuclear power reactors at Kashiwazaki Kariwa shut down automatically, while one of them suffered a short-lived transformer fire and a small amount of water spilled from a used nuclear fuel cooling pool.
The earthquake, centred about 250 km northwest of Tokyo, hit at around 10.13 am, injuring more than 1000 people while destroying 300 buildings. Many roads were cracked, a temple roof collapsed and 35,000 people lost their water supply. Nine were killed.
At the Kashiwazaki Kariwa nuclear power plant, three of seven reactors - units 3, 4 and 7 - were in operation. Those reactors shut down safely as tremors began. Unit 2 was in the process of starting operation, and all systems shut down automatically as well.
Units 1, 5 and 6 were not operating as periodic inspections were being carried out. The tremors caused 1.2 cubic meters of water to spill from the used nuclear fuel cooling pond of unit 6. Plant owners Tokyo Electric Power Company (Tepco) said the water would contain 90 kBq of radioactivity, and had drained from the plant building to the sea in accordance with environmental regulations. The cooling pond itself was undamaged.
There was also a fire in the transformer of unit 3 following the earthquake. Tepco said this had been safely extinguished by 12.10 pm.
Transformers are used in all types of power station. As part of the system connecting the power unit's generator to the transmission grid, they step up the voltage of the electricity generated by the plant for transmission of energy over great distances without high losses. They are large oil-cooled components which deal with very high energy loads. As such they are located in designated and separated area of the plant and provided with ad-hoc monitoring systems, back-up units and fire protection.
In addition, Tepco said hundreds of drums of solid low-level radioactive waste (LLW) in the plant's solid waste storage facility fell from position. The lids of dozens of these were found open. LLW is typically composed of paper, filters, lightly-contaminated clothing and tools. Shigenori Makino of Tepco told World Nuclear News that the LLW drums in the facility contained either ash resulting from the incineration of flammable LLW items, the flammable items prior to incineration, or inflammable items as-is.
Tepco is currently inspecting all seven nuclear power units at the plant to assess what damage, if any, the earthquake may have caused and the exact reason for the transformer failure.
The earthquake was the biggest to affect the region since one of magnitude 6.8 in 2004. At that time no damage was recorded to the Kashiwazaki Kariwa plant.
18/07/07, Japanese Nuclear Power Company Admits Leak Caused by Earthquake Is Bigger Than First Reported, (Back).
KASHIWAZAKI, Japan — The operator of an earthquake-ravaged nuclear plant said Wednesday a radioactive leak from the plant was 50 percent bigger than first reported two days ago. The mayor ordered the facility closed until its safety could be confirmed.
Tokyo Electric Power Co. also said about 400 barrels containing low-level radioactive waste at the Kashiwazaki-Kariwa nuclear plant were knocked over, and the lids had come off 40 of them, as a result of Monday's deadly 6.8-magnitude quake. The announcement revised the company's earlier estimate of 100 tipped barrels.
"We made a mistake in calculating the amount that leaked into the ocean. We apologize and make correction," Tokyo Electric said in a statement. Spokesman Jun Oshima said the amount of radioactive water that leaked into the Sea of Japan was still "one-billionth of Japan's legal limit."
Tokyo Electric spokesman Tsutomu Uehara said no radiation has been detected outside the nuclear plant.
Japanese automakers, meanwhile, called production halts Wednesday at factories because of quake damage at a major parts supplier. Production was scaled back at Toyota Motor Corp., Nissan Motor Co. Mitsubishi Motors Corp. and Fuji Heavy Industries.
Toyota, Japan's No. 1 automaker, will stop production lines at a dozen factories centered in central Aichi prefecture Thursday afternoon and Friday. The shutdown was due to the temporary closure of Riken Corp.'s plant at Kashiwazaki, near the epicenter of Monday's quake.
Toyota will assess the situation at Riken, supplier of key transmission and engine parts, before deciding whether to resume production Monday, he said.
Repair workers on Wednesday climbed over the Kashiwazaki-Kariwa's three-story transformer building, which was charred from top to bottom in a fire Monday.
A tour given to Japan's Communist Party chief, Kazuo Shii, and reporters revealed widespread damage across the sprawling compound, including large cracks in roads, toppled concrete fences and buckled sidewalks.
"This is unforgivable," Shii told TEPCO Deputy Superintendent Masakazu Minamidate. "You say there's no leak before you really know. ... The delay in information was especially inexcusable."
TEPCO President Tsunehisa Katsumata toured the site earlier, declaring it "a mess" and apologizing for "all the worry and trouble we have caused."
"We will conduct an investigation from the ground up. But I think fundamentally we have confirmed that our safety measures worked," he said.
Hiroshi Aida, mayor of Kashiwazaki, a city near the epicenter that is home to the plant and 93,500 people, ordered operations at the plant halted Wednesday for "safety reasons."
The malfunctions and a delay in reporting them fueled concerns about the safety of Japan's 55 nuclear reactors, which have suffered a string of accidents and cover-ups. Nuclear power plants around Japan were ordered to conduct inspections.
Adding to the urgency of any investigation was new data from quake aftershocks that suggested a fault line may run underneath the mammoth power plant.
The Kashiwazaki-Kariwa plant, located 135 miles northwest of Tokyo, has been plagued with mishaps. In 2001, a radioactive leak was found in the turbine room of one reactor. It is the world's largest nuclear plant in power output capacity.
Signs of problems after the quake Monday came first not from the officials, but in a plume of smoke after the quake triggered a small fire at an electrical transformer. Twelve hours later, the company announced the quake also caused a leak of about 315 gallons of water containing radioactive material.
Later Tuesday, it said 50 cases of "malfunctioning and trouble" had been found. Four of the plant's seven reactors were running at the time of the quake, and they were all shut down automatically by a safety mechanism.
Meanwhile, TEPCO spokesman Hiroshi Itagaki said that information accumulated by studying aftershocks shows that a fault line stretches under the ocean near the coast, which is not far from the plant. He declined to say how close to the plant the fault might come.
Osamu Kamigaichi, an official at Japan's Meteorological Agency, which monitors earthquakes, said it was possible the fault line stretched to underneath the plant grounds.
Across the town, more than 8,000 residents hunkered down for their second night in shelters. Late Wednesday, police discovered a 76-year-old man crushed to death under a temple in Kashiwazaki, bringing the quake's fatalities to 10.
For residents, thousands of whom work at the plant, the controversy over its safety compounded already severe problems, which included heavy rains and the threat of landslides, water and power outages.
"Whenever there is an earthquake, the first thing we worry about is the nuclear plant. I worry about whether there will be a fire or something," said Kiyokazu Tsunajima, a tailor who sat outside with his family, afraid an aftershock might collapse his damaged house.
The area around Kashiwazaki was hit by an earthquake three years ago that killed 67 people, but the plant suffered no damage.
The plant's safety record and its proximity to a fault line prompted residents to file lawsuits claiming the government had failed to conduct sufficient safety reviews when it approved construction of the plant in the 1970s. But in 2005, a Tokyo court threw out a lawsuit filed by 33 residents, saying there was no error in the government safety reviews.
(Back)
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