Power was restored to the control room of the No. 3 reactor at the Fukushima Dai-ichi nuclear plant late March 22, and the Tokyo Electric Power Co. plans to try to restart the cooling pumps. Engineers are now trying to reactivate monitoring systems, such as those measuring temperatures of the spent fuel rods. At unit No. 4, a construction vehicle designed to pour concrete for high rises is being used to pump water into the reactor building. International Atomic Energy Agency director general, Yukiya Amano, speaking from Vienna, noted “positive developments,” while warning: “The crisis has still not been resolved and the situation at the Fukushima Dai-ichi nuclear power plant remains very serious,” with “high levels” of radiation measured around the plant. (USA Today, NHK World, NYT, March 22) Hours after the announcement that power had been restored, TEPCO, said black smoke was rising from the No. 3 reactor building. The smoke gradually cleared after about an house, and TEPCO said that the radiation level at plant gate, one kilometer west of the No. 3 reactor, was unchanged at 265.1 micro-sieverts per hour. Gray smoke was seen rising from the same reactor building the previous day. (NHK World, March 23)
High-levels of radiation have been detected in tap water at municipalities across Fukushima Prefecture. Water sampled in Iitate village contained 965 becquerels of radioactive iodine-131 per liter, more than three times the government safety limit of 300 becquerels per liter. Water sampled in Tamura city last week contained 348 becquerels of iodine, but the level was down to 161 becquerels 2 days later. Water from four other cities in the prefecture had iodine levels above the 100-becquerel per liter safety limit for infants as of March 22. Japan’s science ministry has been monitoring radiation levels in all 47 prefectures. (NHK World, March 23)
Radioactive iodine has now been detected in Tokyo tap water in levels above the safe limit for infants. The Tokyo Metropolitan government says 210 becquerels of iodine-131 were detected March 23 in one liter of water at one of its purification plants in northern Tokyo. A sampling the next day also showed roughly 190 becquerels per liter. These levels are below the 300-becquerel per liter safe limit for adults, but far above the 100-becquerel limit for infants.
Tokyo officials say infants in the central 23 wards, plus five adjacent cities, should refrain from drinking tap water. It is also urging beverage makers in these areas not to use tap water in infants’ drinks. Bottled water was rapidly in short supply after the announcement. Chief cabinet secretary Yukio Edano said in a news conference: “Some people began panic-buying drinking water since the radioactive iodine exceeding the provisional standard values was detected in tap water. The government is making utmost efforts to send bottles of drinking water as much as possible to the quake-hit areas. I would like to call on people in Tokyo to avoid panic buying of water.” (NHK World, ENS, March 23)
Japan has halted more shipments of vegetables grown near the Fukushima plant after 11 types of vegetables, including broccoli, cabbage and cauliflower, have been found to have elevated levels of radiation. Shipments of spinach, green leaf vegetables and milk had already been stopped. The US Food and Drug Administration said all dairy products and fresh produce from four Japanese prefectures—Fukushima, Ibaraki, Tochigi and Gunma—will be stopped from entering the country. (BBC News, March 12)
TEPCO is preparing to send a specially designed Monirobo (“Monitoring Robot”) into the reactor buildings to asses damage. A US Air Force drone Global Hawk has also been flying over the plant despite the no-fly zone, providing detailed images of what is happening on the ground. Robots were similarly used after the 1999 Tokaimura nuclear accident. (PC World, March 23)
Tokaimura accident, which caused two deaths at the uranium processing plant near Tokaimura north of Tokyo, was considered the world’s worst nuclear disaster since Chernobyl. Forty workers were treated for radiation exposure. (BBC News, Sept. 30, 2000) 2007 also saw a lesser nuclear accident at Kashiwazaki-Kariwa in Niigata following an earthquake.
See our last post on the Fukushima disaster.