1978, criticality accident occurred at Fukushima Daiichi nuclear power plant, but the accident was concealed until 2007.
In August 2005, an earthquake measuring 7.2 on the Richter scale caused some pool water stored in two nuclear power plants in Fukushima Prefecture to overflow.
In 2006, a radioactive material leakage accident occurred in Unit 6 of Fukushima Daiichi Nuclear Power Plant.
In 2007, TEPCO admitted that it had tampered with the data and concealed potential safety hazards during the total of 199 regular inspections of its three nuclear power plants starting from 1977. Among them, the data measured by the flowmeter in the main steam pipeline of Fukushima Daiichi Nuclear Power Plant 1 Unit was tampered with 28 times from 1979 to 1998. Former chairman of Tokyo Electric Power Company resigned.
In June 2008, a small amount of radioactive cooling water leaked from the nuclear reactor of Fukushima nuclear power plant. Officials said that this did not harm the environment or people.
The recent accident
20 1 1 In March, an earthquake measuring 9.0 on the Richter scale led to the failure of two nuclear power plants in Fukushima Prefecture, one of which was the first nuclear power plant after the earthquake.
An abnormality occurred, resulting in nuclear steam leakage. A small explosion occurred on March 12, or it was caused by hydrogen explosion. Some insiders said that the Fukushima nuclear power plant is a single-layer circulating boiling water reactor, which is now technically useless. Cooling water is directly introduced into seawater, so the safety is unpredictable. Steam produced by boiling water. For an earthquake-prone area like Japan, it is very unreasonable to adopt such a structure. An explosion occurred after the March 14 earthquake. After the explosion, radioactive substances entered the wind and spread to Chinese mainland, Taiwan Province Province, Russian and other regions.
Tokyo Electric Power Company 16 said in the morning that a fire broke out again at the Fukushima Daiichi nuclear power plant that morning. The company also confirmed that the whereabouts of two nuclear power plant workers are unknown and have not yet been found. Tokyo Electric Power Company held an emergency press conference on the morning of 16, saying that the No.4 reactor of the nuclear power plant had another fire at 5: 45 Tokyo time (4: 45 Beijing time). A spokesman for the Tokyo Electric Power Company said that employees of the company have confirmed the occurrence of the fire and have urgently notified the Fukushima prefectural government and the fire department.
Japanese officials said at 8 am Tokyo time 16 that the fire was under control. However, the details of the No.4 reactor are not known at present. It is reported that this fire is similar to the fire that occurred on June 5438+05. On June 5438+05, Director General of the International Atomic Energy Agency (IAEA) Yukiya Amano said that the IAEA had not received the Japanese government's explanation on the situation after the fire in Reactor 4 of the nuclear power plant on June 5438+05.
Tokyo Electric Power Company also confirmed that the whereabouts of two nuclear power plant workers are unknown. However, the company argued that the two workers disappeared after the earthquake on June 5438+0 1, not after the explosion of the nuclear power plant on June 5438+05. "Gen Nakatani, Permanent Representative of Japan to the International Organizations in Vienna, told Kyodo News on June 5438+05 that the Japanese government has requested the International Atomic Energy Agency to send an expert team to help deal with the nuclear power plant accident caused by the earthquake in Japan within a few days at the earliest. It is expected that the IAEA will first send an environmental monitoring team. Nagan said that because the vicinity of the nuclear power plant was very inaccessible, it was initially expected that only a small-scale expert team could be sent.
Japanese Prime Minister Naoto Kan delivered a speech to the Japanese people on June 5438+05 on the Fukushima Daiichi nuclear power plant. He asked all residents within 20km of Fiona Fang Nuclear Power Station to evacuate, and residents within 20km to 30km of Fiona Fang to take shelter indoors. According to reports, Naoto Kan denounced TEPCO for "bullying the upper and deceiving the lower". At present, radioactive isotopes of cesium and iodine have been detected near nuclear power plants. Experts believe that it is natural for radioactive isotopes of nitrogen and argon to leak out, and plutonium leakage has also occurred, which is very worrying.
At about 1 1 32 pm local time on the 7th (Beijing time 1 32 pm), a strong earthquake measuring 7.4 on the Richter scale occurred in Miyagi Prefecture in northeastern Japan. According to the Kyodo News Agency, at present, there are no other abnormal situations in Japan's nuclear power plants except power outages. Tokyo Electric Power Company said that as of the afternoon of the 7th local time 1 1 52, there was no leakage of radioactive materials caused by the earthquake at the Fukushima Daiichi nuclear power plant.