Up power plant accident

New Delhi: Thirteen workers have been injured after a tin shed fell on them throughout upkeep work at a thermal power plant in Uttar Pradesh this morning. The incident happened throughout upkeep work on the boiler unit at Lanco Anpara Power Limited, positioned in the Sonbhadra district, which is about 350 km from the state capital, Lucknow An explosion at a Nevada rocket fuel plant generates a massive, earthquake-like shockwave.Subscribe to Discovery! | http://www.youtube.com/subscription_cente.. The accident at a nuclear power plant in Ukraine shocked the world, permanently altered a region, and leaves many questions unanswered. By Erin Blakemore Published May 17, 201

The Three Mile Island accident was a partial meltdown of reactor number 2 of Three Mile Island Nuclear Generating Station (TMI-2) in Dauphin County, Pennsylvania, near Harrisburg, and subsequent radiation leak that occurred on March 28, 1979. It is the most significant accident in U.S. commercial nuclear power plant history. On the seven-point International Nuclear Event Scale, the incident. On Monday a French nuclear company, Framatome, announced it is supporting efforts to resolve a 'performance issue' with its Taishan Nuclear Power Plant in China's heavily populated Guangdong Province, raising concerns about a potential nuclear leak. The nuclear plant is located in Guangdong, which according to Chinese census estimates for 2020, has an estimated population of about 126 million. HELSINKI, Finland (AP) _ The Soviet Union confirmed Thursday that a major accident occurred at a nuclear power plant in Leningrad in 1975, Finnish officials said. The officials said the nuclear reactors in the Leningrad plant were similar to those at Chernobyl and that the accident was ''possibly of grade 3 - in other words, a serious accident.'' Radioactivity spread over parts of northern. Fukushima accident, also called Fukushima nuclear accident or Fukushima Daiichi nuclear accident, accident in 2011 at the Fukushima Daiichi (Number One) plant in northern Japan, the second worst nuclear accident in the history of nuclear power generation. The site is on Japan's Pacific coast, in northeastern Fukushima prefecture about 100 km (60 miles) south of Sendai At 4 a.m. on March 28, 1979, the worst accident in the history of the U.S. nuclear power industry begins when a pressure valve in the Unit-2 reactor at Three Mile Island fails to close. Cooling.

The plant relies on the power grid. If the grid is no longer available, the plant switches to diesel generators. If there is an issue with the diesel generators, there is a battery backup. Why Nuclear Power Plants Require Power From The Grid. Nuclear reactors produce much more electricity than they need to run their systems Chernobyl is a nuclear power plant in Ukraine that was the site of the worst nuclear accident in history when a routine test went horribly wrong on April 26, 1986 Fukushima Daiichi Accident. (Updated April 2021) Following a major earthquake, a 15-metre tsunami disabled the power supply and cooling of three Fukushima Daiichi reactors, causing a nuclear accident beginning on 11 March 2011. All three cores largely melted in the first three days Chernobyl disaster, accident at the Chernobyl nuclear power station in the Soviet Union in 1986, the worst disaster in nuclear power generation history. Between 2 and 50 people were killed in the initial explosions, and dozens more contracted serious radiation sickness, some of whom later died The French power company that co-owns a nuclear plant in China would shut it down if it could, due to damage to the fuel rods, a spokesperson said -- but the decision is ultimately up to the plant.

13 workers injured in accident at UP power plant

  1. The Fukushima nuclear power plant accident was the result of collusion between the government, the regulators and Tepco [plant operator Tokyo Electric Power], and the lack of governance by said.
  2. A duplicate diet study 3/ undertaken in the Aomori Prefecture of Japan during 2006 to 2010 (before the accident at the Fukushima Daiichi nuclear power plant) reported a mean annual ingestion dose of 0.47 mSv/year with most of this ingestion dose being attributed to the naturally occurring radionuclides: lead-210, polonium-210 and potassium-40.
  3. The nuclear accident at the Fukushima-Dai'ichi nuclear plant in Japan, which began nearly one year ago, on March 11, 2011, has had a major impact on how Americans view the risks of nuclear power
  4. The Enrico Fermi Nuclear Generating Station is a nuclear power plant on the shore of Lake Erie near Monroe, in Frenchtown Charter Township, Michigan on approximately 1,000 acres (400 ha). All units of the plant are operated by the DTE Energy Electric Company and owned (100 percent) by parent company DTE Energy.It is approximately halfway between Detroit, Michigan, and Toledo, Ohio
  5. Counting two accidents over the accumulated power production to the end of 1994 one gets a 10 −4 per TWh frequency, or a 5 × 10 −5 per TWh frequency for an accident with severe external consequences. At the time of the Chernobyl accident, the estimate would have been 3-4 times higher owing to the much lower accumulated power production.

US assessing possible nuclear accident at Taishan. First COVID-19, and now possibly Taishan. China's claims to competence in cutting-edge science appears on the verge of tatters if reports about a nuclear accident at its reactor turn out to be true. CNN reports that a French company partnering at the Taishan nuclear power plant took the. Fifty miles away was the Chernobyl nuclear power plant. On 26 April 1986 reactor number four at the power plant suffered a catastrophic explosion that exposed the core and threw clouds of. China Guangdong Nuclear Power Group told state outlet the Global Times that the nuclear plant has operated the reactors strictly in compliance with business licence documents and technical procedures The plant would probably be back up and running by now. Japan, for whatever reason, has two electrical frequencies (50 Hz and 60 Hz). And, you can't run a 50 Hz motor at 60 Hz or vice versa. So, whatever frequency the plant was using/providing is the frequency they need to power up Reviews of the accident have focused on the effects of earthquakes and floods, as well as positioning plants to deal safely with a complete loss of off-site and back-up power. Nuclear power plants worldwide are addressing these issues with steps that include: re-examining external hazards, improving electrical systems

Destroyed in Seconds- Chemical Plant Explosion - YouTub

Eight years after the accident in Fukushima, preparations are underway to restart the Kashiwazaki-Kariwa nuclear power plant operated by Tepco. But residents fear a second disaster. Kiyo Dörrer. The earthquake and tsunami that struck eastern Japan on March 11, 2011, caused a serious accident at the Fukushima Dai-ichi nuclear power plant on the northeastern coast of Japan. How did it happen? The earthquake cut off external power to the reactors. tsunami, which reached levels more than twice as high as the plant was designed to withstand. The new warning is the most serious since the plant was struck by a powerful tsunami on 11 March 2011. The wave, triggered by a magnitude 9.0 earthquake off Japan's north-east coast, wrecked the plant's back-up power supply and sent three of its six reactors into meltdown

Lanco Infratech commissions second 600-MW unit of Anpara project in UP. 14 Nov, 2011, 01.00 PM IST. Lanco Infratech said it has commissioned the second unit of the 1,200-MW Anpara thermal power plant in Uttar Pradesh, taking the entity's total installed capacity to 3,892 MW Safety of Nuclear Power Reactors. The risks from western nuclear power plants, in terms of the consequences of an accident or terrorist attack, are minimal compared with other commonly accepted risks. Nuclear power plants are very robust. News and information on nuclear power, nuclear energy, nuclear energy for sustainable development, uranium mining, uranium enrichment, nuclear generation of.

The 1986 Chornobyl nuclear power plant accident. On 26 April 1986, the Number Four reactor at the Chornobyl Nuclear Power Plant in what then was the Soviet Union during improper testing at low-power, resulted in loss of control that led to an explosion and fire that demolished the reactor building and released large amounts of radiation into. On April 26, 1986, a sudden surge of power during a reactor systems test destroyed Unit 4 of the nuclear power station at Chernobyl, Ukraine, in the former Soviet Union. The accident and the fire that followed released massive amounts of radioactive material into the environment. Emergency crews responding to the accident used helicopters to. Although power plants are much safer than they once were, plant employees still encounter many hazards, and it is up to employers to implement programs and policies aimed at eliminating accidents Truth is there have been a lot of nuclear power plant accidents that resulted in radioactive waste spilling out into the environment. Not nearly to the scale of those three, but still enough to negatively affect the lives of poorer communities. Because that's who is affected by accidents at these plants. Poor people

Chernobyl disaster facts and informatio

09:30 - Staff at the Forsmark Nuclear Power Plant, Sweden, detect a dangerous surge in radioactivity. Initially picked up when a routine check reveals that the soles shoes worn by a radiological safety engineer at the plant were radioactive. 21:02 - Moscow TV news announce that an accident has occurred at the Chornobyl Nuclear Power Plant Another advantage of using nuclear energy is that it is relatively cost-effective - the initial cost of building the nuclear plant is the greatest hurdle in setting up power plants. However, problems and accidents can happen inside nuclear plants that may affect a large area surrounding the plant. This is extremely harmful for those living. Currently, it's stored in up to a thousand large tanks, but the government and Tepco [Tokyo Electric Power Company], the plant operator, say this strategy is not viable for the long-term future. Instead, the water must be released into the sea, possibly over a decade or so, though arrangements are yet to be confirmed

Three Mile Island accident - Wikipedi

Radiation exposure caused by last year's accident at the Fukushima Daiichi nuclear power plant was below levels thought to increase the risk of cancer in almost all parts of Japan, according to a. The top five accidents ranked by monetary cost are the Fukushima accident in March 2011, the Chernobyl explosion in April 1986, a fire at the Tsuruga nuclear plant in December 1995, a fire at. The rule also would have required such plants to evaluate whether they need greater safety improvements and emergency preparedness, such as storing fewer chemicals, improving storage safety, and strengthening backup power so electricity would be maintained in a storm, and devising other ways to operate more safely and reduce hazards before.

Engineers and workers present on the accident spot at that time also told the seniors that coal powder pumped into the furnace developed, what in thermal power plants jargon, is called a clinker formation which ultimately choked the valves. Those present, reportedly say, that workers were pressed into service to break the clinkers This was what happened at the eight reactors sited at the Daini, Onagawa and Tokai plants, which were able to access the back-up power needed to run the cooling process. At Fukushima Daiichi, however, the process failed. The result was the largest nuclear disaster since the Chernobyl accident in 1986 in what is now Ukraine. A seismic countr Cleaning up the contamination could be financially costly for the Chinese and French state companies that own the plant, says Schneider. More on these topics: nuclear power

Burst steam pipe causes explosion at power plant in

On 26 April 1986, the worst nuclear accident in the history of humankind occurred at the Chernobyl nuclear power plant accident in Ukraine. The disaster that was rated highest at the International Nuclear Event Scale (INES) and affected the environment and the lives of millions of people in Belarus, Ukraine and the Russian Federation. Evacuation and relocation proved a deeply traumatic. The Chernobyl disaster was a nuclear disaster which occurred on April 26, 1986 at the Chernobyl nuclear power plant in Pripyat, Ukraine.At that time, Ukraine was part of the Soviet Union.The station was situated just 110 km North of Kyiv. This event was one of the worst accidents in the history of nuclear power.It was rated level 7, the most severe level, on the International Nuclear Event Scale T he French utility that partly owns a nuclear power plant near Hong Kong is seeking more information on a gas buildup in a reactor, even as its Chinese partner insists the facility is operating. Both historical nuclear power plant accidents released tons of radioactive cesium to the environment. Consequently, the radioactive cesium found their way to the surrounding land, river, into the. According to reports, China has admitted that about five of the fuel rods in the reactor are damaged, but the plant is said to be capable of operating safely with up to 0.25% of its 60,000 fuel.

Damaged Chernobyl reactor covered 33 years after nuclear

The China Syndrome: Directed by James Bridges. With Jane Fonda, Jack Lemmon, Michael Douglas, Scott Brady. A reporter finds what appears to be a cover-up of safety hazards at a nuclear power plant These modifications would allow plant operators additional methods to further mitigate a number of scenarios including earthquakes, tsunamis, fires, station blackouts and severe accidents. For example, we have a number of back-up power options in the event we lose power on site. One of these back-up power supplies is the AAC March 11, 2021, 2:22 PM. On Thursday, Japan commemorated the 10th anniversary of the March 2011 earthquake, tsunami, and nuclear plant accident that was a defining moment even in a country well. The radiation released by the disaster at the Fukushima Daiichi Nuclear Power Plant was about 5.5% of that of the Chernobyl accident.3,4 At the time of the accident, prevailing winds blew much of the radiation eastward and out to sea.2 This event marked the world's most significant radiological accident in 25 years

Chinese nuclear plant likely leaking near 126 million

The state-run China General Nuclear Power Group, better known as CGN, owns 70 percent of the Taishan plant, and EDF owns the rest. The French companies and the Chinese plant did not immediately. Chernobyl nuclear power plant. Power plants today are much safer BIGSTOCKThe mistakes of the past don't repeat themselves in today's power plants Millions of people (over 4 million according to the WHO) are killed each year by outdoor air pollution 'Accident' at Iran's Natanz nuclear plant as new uranium enrichment starts This article is more than 3 months old Spokesman says accident hit the Natanz electrical distribution grid, a day.

Soviets Confirm Accident at Leningrad Nuclear Plant in 197

The Chernobyl accident is the most serious accident in the history of the nuclear industry. Indeed, the explosion that occurred on 26 April 1986 in one of the reactors of the nuclear power plant, and the consequent fires that lasted for 10 days, led to huge amounts of radioactive materials being released into the environment and a radioactive cloud spreading over much of Europe Chernobyl's nuclear fuel is 'smoldering' again and could explode. By Brandon Specktor - Senior Writer May 14, 2021. Tons of nuclear fuel in the wrecked plant's basement has started to react again. As with other accident-tolerant fuel concepts, the aim is to provide time to stabilize a power plant during a severe accident. Fawcett says that in a blackout situation similar to Fukushima's, research suggests that GE's cladding products could buy between three and six hours The earthquake and tsunami caused a major nuclear power plant (NPP) accident at the Fukushima Dai-ichi, owned by Tokyo Electric Power Company (TEPCO). The accident was likely more severe than the 1979 Three Mile Island and less severe than the Chernobyl 1986 accidents. Yet, after the 26 December 2004 Indian Ocean tsunami had hit the Madras. Four months after a fire shut it down, a nuclear reactor at the South Texas Project in Bay City is being restarted. That is the second prolonged shutdown at the plant in two years, prompting.

Fukushima accident Summary, Date, Effects, & Facts

Evacuation after the Fukushima Daiichi Nuclear Power Plant Accident Is a Cause of Diabetes: Results from the Fukushima Health Management Survey J Diabetes Res . 2015;2015:627390. doi: 10.1155/2015/627390 The government is in talks with China and Russia about setting up a nuclear power plant in the Kingdom. A senior official says the three countries have signed a memorandum of understanding (MoU) The Fukushima nuclear accident as a part of a triple disaster was unprecedented in its scale and nature. A number of lessons were learned that help Japan and all countries better plan, prepare, respond and recovery from potential nuclear accidents. These include: Evacuation aims to minimize or prevent health risks of radiation exposure

Three Mile Island Disaster - HISTOR

  1. The operators of D.C. Cook Nuclear Power plant plan to invest about $50 million to stabilise alternative emergency power supplies through measures such as back-up batteries and generators. Keen to.
  2. der of the need to revisit emergency plans to ensure that emergency responders are able to respond to both a problem at a nuclear power plant and the needs of the surrounding community
  3. An explosion at a power plant yesterday killed at least 16 workers and seriously injured up to 100, police said. The blast occurred at a coal-fired power plant in Rae Bareli district of Uttar.

Nuclear Power Plants: When Backup Systems Fai

The IAEA released a report on The Fukushima Daiichi Accident in 2015 with all relevant details. The report highlights that the units overheated because the tsunami caused flooding in the area of the plant where the back-up generators were located, rendering them unable to restore power to maintain the cooling of the reactors There were two official explanations of the accident: the first, later acknowledged to be erroneous, was published in August 1986 and effectively placed the blame on the power plant operators. The second report published in 1992 was less critical of the operators and placed much greater emphasis on the design of the reactor itself

Chernobyl: Disaster, Response & Fallout - HISTOR

Next nuclear disaster? A reactor at Taishan Nuclear Power Plant has fuel rods damaged but Chinese officials don't want to close it down! French energy company EDF has announced that it would shut down a reactor at the Taishan Nuclear Power Plant in China's Guangdong province due to damage to its fuel rods if it could. But the decision is ultimately up to the plant's Chinese operato MORGAN COUNTY, Colo. (CBS4) - Crews are battling an uncontrolled coal fire at an Xcel plant in Morgan County. The fire inside a storage facility at the Pawnee Power Plant in Fort Morgan prompted. The Dark Horse - Nuclear Power and Climate Change This is a sample chapter from our recent book The Dark Horse - Nuclear Power and Climate Change (link to Amazon store). The book was published in 2020, and this article came out on the 10th anniversary of the Fukushima accident. It is our effort t 4/28/1986: Chernobyl Disaster. Damaged atomic reactor at Soviet Union's Chernobyl plant causes radiation leak. LIVE. 00:00 / 04:25. GO LIVE

The accident occurred after one of the steam pipes blew up as the engineers were preparing one of the units in order to step up power from 43MW to 65MW. Sh40 billion power plant will be. A North Georgia chicken plant and its associated companies face $1 million in fines and scores of citations from the U.S. Labor Department over the deaths of six workers and injuries of a dozen in. Aviation Disasters And Plane Crashes In History:Lauda Air Flight 004 - 223 dead: On 26 May 1991 flight 004 from Bangkok to Vienna broke up in the air near th.. The wave, triggered by a magnitude 9.0 earthquake off Japan's north-east coast, wrecked the plant's back-up power supply and sent three of its six reactors into meltdown

Fukushima Daiichi Accident - World Nuclear Associatio

  1. Back-up power is very important in such accidents. Diesel power gives life to reactors after the plant shuts down. It cools the reactor to ensure that there is no meltdown
  2. The immediate area around the plant had to be evacuated, but no lives were lost from radiation leakages. The two disasters have cast a long shadow on the public's perception of nuclear power. In the immediate aftermath of the Fukushima accident, survey data showed that 62 percent of people around the world opposed nuclear power
  3. 1. Introduction. The paper uses the J-value (Thomas et al., 2006a, Thomas et al., 2010) to analyse a range of remediation measures that were applied following the big nuclear power plant accidents at Chernobyl in 1986 and Fukushima Daiichi in 2011.The Judgement- or J-value balances the cost of the action against the safety benefit so as to preserve the notional quality of life of those.
  4. On 11 March 2011, the Fukushima-Daiichi nuclear power station (FDNPS) suffered major damage after the magnitude 9.0 great east-Japan earthquake and subsequent tsunami. It was the largest civilian nuclear accident since the Chernobyl accident in 1986. Radioactive material was released from the damaged plant and tens of thousands of people were.
  5. The safety of the plant is enhanced due to a number of key features, such as a simplified design, inherent cooling capabilities, passive engineered safety features, and lower core power density. In the extremely unlikely event that a NuScale core is damaged, consequences would be well below the threshold to warrant off-site evacuations

An exclusion zone was not set up around Chernobyl until 36 hours after the accident. At first, the exclusion zone was 10km long, which saw the evacuation of 49,000 people from the town of Pripyat The IDA cognitive model for the analysis of nuclear power plant operator response under accident conditions. Part I: problem solving and decision making model Reliability Engineering & System Safety, 199 The Three Mile Island accident was a partial nuclear meltdown that occurred on March 28, 1979, in reactor number 2 of Three Mile Island Nuclear Generating Station (TMI-2) in Dauphin County, Pennsylvania, United States.It was the worst accident in U.S. commercial nuclear power plant history. The incident was rated a five on the seven-point International Nuclear Event Scale: Accident With Wider. The plant is co-owned by China General Nuclear Power Group, which is also the major shareholder of the plant. EDF holds only a 30 percent stake in Taishan Nuclear Power Joint Venture Co

Melted Nuclear Core at Fukushima Finally Discovered by

Five years after a powerful earthquake and tsunami sent the nuclear power plant in the country into multiple meltdowns, cleaning up the mess remains a work in progress AEOI said the plant will be brought back online and reconnected to the national power grid within a few days after addressing a technical fault. Although AEOI said the operators of Iran's only nuclear power plant gave a day's advance notice, Al Jazeera News described the situation as the first emergency shutdown of the facility.

Chernobyl disaster Causes & Facts Britannic

  1. The Chernobyl nuclear accident refers to the events in the Chernobyl nuclear power plant on April 26 th 1986. Different articles discuss the radiation release from the Chernobyl nuclear accident and the health effects of the Chernobyl nuclear accident.However, this page will discuss the mechanisms of the the power plant and what lead to the disaster. It is the largest major nuclear accident to.
  2. In 2011, the Fukushima Daiichi Nuclear Power Plant in Japan was badly damaged by a 9.0-magnitude earthquake and resulting tsunami. Three reactors up and running at the time were shut down 7.10: Fukushima Nuclear Disaster - Chemistry LibreText
  3. While already considered safe, US nuclear power plants should improve their preparedness for major accidents and ensure that back-up power sources would be available, a task force has recommended to the country's regulator. As well as addressing plant safety, the group also suggested ways of improving the USA's nuclear safety regulatory framework

Taishan Nuclear Power Plant: Situation in China serious

The safety of the Loviisa power plant has been ensured by numerous different systems. For example, the plant has many back-up power systems to prepare for power outages that may be caused by external events. Although the probability of a severe reactor accident is very low, the Loviisa power plant was one of the first in the world to install. ESCANABA — Power is out after a explosion at the Escanaba Power Plant Monday morning. Officials tell ABC 10 that the power outage began at around 1:30 a.m., due to a fire at a substation. There.

are licensed by the NRC to operate up to a maximum thermal power level. At Calvert Cliffs, that limit on reactor power output is 2,700 megawatts thermal (Mwt). The plant can generate as much electricity as it can as long as the reactor power remains equal to or below 2,700 Mwt. Due to thermodynami The Martin Drake Power Plant downtown is aiming to cease burning coal in September as part of a transition to cleaner energy sources within Colorado Springs Utilities. Utilities only has one coal.

Japan tsunami: Fukushima Fifty 'on suicide mission' to

Japanese panel: Fukushima a 'man-made' disaster

  1. Climbing Without a Map: Japan's Nuclear Clean-Up Has No End in Sight. The storage tanks for treated water are seen at the tsunami-crippled Fukushima Daiichi nuclear power plant in Okuma town.
  2. g that hundreds of thousands of people died from the radiation, specially in places 100s of.
  3. Iran's Bushehr nuclear power plant has emergency shutdown - state TV Iran has witnessed dozens of mysterious fires and explosions across the country since mid-2020, many near nuclear facilities
  4. es the associations of radiation dose and lifestyle factors with incidence of thyroid cancer in Fukushima. Methods: We designed a prospective study with 300,473 participants aged 18 years or younger, who underwent thyroid exa
  5. Catch up on the developing stories making headlines. The Associated Press. HONG KONG -- China's government said Tuesday no abnormal radiation was detected outside a nuclear power plant near Hong.
  6. Plant accidents and equipment failure caused by asset damage can be extremely dangerous for both facility personnel and the surrounding environment. We have a comprehensive array of inspection , engineering , maintenance , monitoring , and access services for a variety of power generation assets, including
  7. DAE is setting up a second Nuclear Fuel Complex (NFC) - a PHWR fuel plant at Kota in Rajasthan, next to the Rawatbhata power plant - to serve the larger new reactors and those in northern India. It will have 500 t/yr capacity, from 2017, and government approval of Rs 2400 crore (24 billion rupees, $393 million) for this was in March 2014
Chernobyl Nuclear Power Plant | Chernobyl Nuclear PowerOhio town braces for possible closure of Davis-Besse

Fukushima Daiichi Power Plant Disaster • Took Place On: March 11 th 2013 • Where: Fukushima Daiichi Power Plant in Okuma, Japan • Cause: The Tohoku earthquake and resulting tsunami • What Happened: • Damage only suffered from Tsunami • Lower levels of plant were flooded • Reactors 1, 2, and 3 melted down • Hydrogen explosions • 20 km evacuations (Wikipedia) Nuclear power capacity is replaced by reducing surplus electricity exports, by using the reserve capacity of traditional back-up power plants for peak times, and by temporarily importing. The Three Mile Island nuclear power plant, site of the nation's worst nuclear accident, will shut down by the end of September. Backers failed to secure subsidies to keep the plant operating The Three Mile Island accident occurred on March 28, 1979, in reactor number 2 of Three Mile Island Nuclear Generating Station (TMI-2) in Dauphin County, Pennsylvania, United States, near Harrisburg.It was the most significant accident in U.S. commercial nuclear power plant history. The incident was rated a five on the seven-point International Nuclear Event Scale: Accident with wider. Comparison of Fukushima and Chernobyl nuclear accidents: | The following table compares the |nuclear accidents| at |Fukushima Daiichi| (2011) and |C... World Heritage Encyclopedia, the aggregation of the largest online encyclopedias available, and the most definitive collection ever assembled The Tokyo Electric Power Co., operator of the crippled Fukushima plant, was forced to shut down its massive seven-unit nuclear plant at Kashiwazaki-Kariwa after a major earthquake in 2007