The radiation of the damaged reactor is extremely strong. And the decommissioning of the Fukushima nuclear power plant will be delayed?
Xinhua News Agency, Beijing, January 28 (Reporter Liu Xiuling) Japan is about to usher in the”March 11″ earthquake and the occurrence of the tsunami On the occasion of the tenth anniversary, an investigation report showed that many damaged reactors buildings of the Fukushima Daiichi Nuclear Power Plant had extremely strong radiation. The difficulty of taking out spent fuel rods (used nuclear fuel rods) from the reactor may further delay the scrapping operation of the Fukushima nuclear power plant.
According to the”Tokyo Shimbun” report on the 27th, an investigation team of the Japan Nuclear Regulatory Commission released this report on the 26th. The concrete containment top cover of Fukushima Unit 1 wrapped the reactor pressure vessel was displaced and dropped during the hydrogen explosion, and the top covers of Units 2 and 3 remained in place. These roofs are made of 3 layers of reinforced concrete, each about 12 meters in diameter and weighing about 465 tons.
A photo released by Japan’s Fukushima Nuclear Power Plant operator and Tokyo Electric Power Company on March 16, 2011 It shows the damage and white smoke emission of the third reactor (left) after the explosion and the status of the fourth reactor (right). (Xinhua News Agency/EPA Europe and New Zealand)
The investigation report estimates that the activity of radioactive cesium attached to the containment cover of Unit 1 is between 100 trillion and 200 trillion Becquerels, and that of Unit 2 is 2. From trillion to 4 trillion becquerels, unit 3 is 3 trillion becquerels.
Kyodo News interpreted that when the Fukushima nuclear accident occurred, the radioactive activity in units 1 to 3 The degree is estimated to total 70 trillion becquerels. This means that about one-tenth of the radiation remains on the top of the reactor containment.
The amount of radiation near the top cover of the containment is also amazing. Among them, the maximum radiation value of Unit 2 building is 10 sievert per hour. People exposed to this intensity of radiation will die in about an hour.
On March 7, 2015, in Japan Fukushima Prefecture Big Bear Town, a street sign indicates Fukushima No. 1 The direction of the nuclear power plant. (Photo by Xinhua News Agency reporter Liu Tian)
The Japanese government and Tokyo Electric Power Company are promoting the scrapping of the Fukushima nuclear power plant. The removal of spent fuel rods is regarded as the “most difficult task”. Among the four units, the less damaged Unit 4 has all taken out the spent fuel rods in December 2014. According to the scrapping schedule set by the Japanese government and TEPCO, all spent fuel rods should be removed in 2031 and scrapped between 2041 and 2051.
The latest survey results undoubtedly increase the difficulty of taking out the spent fuel rods, which means that it is difficult to take out the spent fuel rods by opening the containment vessel.”Tokyo Shimbun” interpreted that the Japanese government and TEPCO will have to modify the scrapping schedule.
On March 11, 2011, a magnitude 9.0 earthquake occurred in the seas of northeastern Japan and triggered a tsunami, which caused the Fukushima Nuclear Power Plant to be powered off, the cores of the three units were melted down one after another, and a large amount of radiation leaked.
The investigation team of the Nuclear Regulatory Commission is responsible for analyzing the Fukushima nuclear accident, and the investigation results were released in October 2014. The latest report summarizes the survey results after September 2019 and is 326 pages long.