The nuclear emergency at the stricken Japanese power plant took an unexpected turn on Wednesday night as the focus switched to a reactor previously declared stable.
Image 1 of 2
The smouldering remains of the Fukushima Daiichi nuclear plant Photo: REUTERS
Attention had been concentrated on Fukushima's three working reactors and it was believed that the site's other three offline generators were safe. But, following a fresh explosion and fire, officials have now admitted that the problem has spread to Reactor No 4.
The new threat lies not from the actual core of the reactor, which at the time of last Friday's earthquake was being refurbished, but in its adjacent cooling pond where its spent fuel had been placed in storage.
Engineers said that the 45ft–deep pool was heating up and had boiled dry, exposing the still highly reactive fuel to the atmosphere.
This is particularly worrying because, unlike the three active reactors, there is no protective flask to catch the fallout.
The building housing the pond has also been breached by the latest explosion and fire, which means that iodine–131, caesium–137 and other contaminants emitted by any crippled rods could enter the atmosphere directly. There were "extremely high" radiation levels at the site, the US Nuclear Regulatory Commission said.
The reactor pool at No4 was worst hit but Five and Six were also heating up. There is a possible crack in the spent fuel pool in Reactor Three, "which could lead to a loss of water in that pool" while the spent fuel pool level in Reactor Two "is decreasing", according to the US Nuclear Regulatory Commission.
France's Nuclear Safety Authority described the No4 pool as "the major concern". The situation was said to be exacerbated by high levels of radiation, making it impossible for workers to get close to the pool. An attempt to refill it with seawater dropped by a military helicopter had to be abandoned for fear of contamination.
Engineers were planning to attempt to use water cannon to refill the reservoirs overnight. The Union of Concerned Scientists, a respected non–governmental group based in the United States, said on its website that the No4 pool was a "particular problem" because the rods were only removed from the reactor in December, during a refuelling operation. "They still have a very high level of radiation and are generating more heat than the spent fuel at the other reactors," the union said.
"Even if the water level was at the top of the fuel rods, the radiation dose to someone at the railing of the pool would give them a lethal dose in well under a minute." The unexpected turn of events is bound to lead to further criticism of the power plant's operator, the Tokyo Electric Power Company (Tepco), and questions as to whether it put in place adequate safety measures.
John Price, an Australian–based nuclear safety expert, said he was surprised by how little information the Japanese were sharing. "We don't know even the fundamentals of what's happening, what's wrong, what isn't working," he said. "I would have thought they would put up a panel of experts every two hours."
The head of the International Atomic Energy Agency, Yukiya Amano, demanded that Tepco be more transparent about the ongoing situation. He called on company executives to provide more "timely and detailed information" about developments.
Even the Japanese Prime Minister, Naoto Kan, has said that he has been finding out about developments from television. Tepco has been criticised in the past over its safety record. In 2002, the chairman and four other executives were forced to resign after being accused of falsifying safety reports at the Fukushima plant.
Details of the explosion at the fourth reactor were only released more than 20 hours after the incident this week. Critics suggested that it was attempting to cover up news of the worsening situation.
France's Nuclear Safety Authority described the No4 pool as "the major concern". The situation was said to be exacerbated by high levels of radiation, making it impossible for workers to get close to the pool. An attempt to refill it with seawater dropped by a military helicopter had to be abandoned for fear of contamination.
Engineers were planning to attempt to use water cannon to refill the reservoirs overnight. The Union of Concerned Scientists, a respected non–governmental group based in the United States, said on its website that the No4 pool was a "particular problem" because the rods were only removed from the reactor in December, during a refuelling operation. "They still have a very high level of radiation and are generating more heat than the spent fuel at the other reactors," the union said.
"Even if the water level was at the top of the fuel rods, the radiation dose to someone at the railing of the pool would give them a lethal dose in well under a minute." The unexpected turn of events is bound to lead to further criticism of the power plant's operator, the Tokyo Electric Power Company (Tepco), and questions as to whether it put in place adequate safety measures.
John Price, an Australian–based nuclear safety expert, said he was surprised by how little information the Japanese were sharing. "We don't know even the fundamentals of what's happening, what's wrong, what isn't working," he said. "I would have thought they would put up a panel of experts every two hours."
The head of the International Atomic Energy Agency, Yukiya Amano, demanded that Tepco be more transparent about the ongoing situation. He called on company executives to provide more "timely and detailed information" about developments.
Even the Japanese Prime Minister, Naoto Kan, has said that he has been finding out about developments from television. Tepco has been criticised in the past over its safety record. In 2002, the chairman and four other executives were forced to resign after being accused of falsifying safety reports at the Fukushima plant.
Details of the explosion at the fourth reactor were only released more than 20 hours after the incident this week. Critics suggested that it was attempting to cover up news of the worsening situation.
0 التعليقات
Post a Comment