A group of Japanese researchers say that a total of 15,000 terabecquerels of radioactive substances is estimated to have been released from the crippled Fukushima Daiichi nuclear power plant into the sea.
Researchers at the Japan Atomic Energy Agency, Kyoto University and other institutes made the calculation of radioactivity released from late March through April.
Tepco general manager Junichi Matsumoto. Most, but not all, of the molten fuel is believed to have stayed inside the containment vessels.
Tokyo, May 18 (Jiji Press)–A Japanese special cabinet adviser has said in public that low-level radioactive water was dumped into the sea from the crippled nuclear power plant at the request of the U.S. government, informed sources said Wednesday.
Tokyo Electric Power Co. began the dumping of low-level radioactive water from its Fukushima No. 1 nuclear plant on April 4 in order to secure space to store highly radioactive liquid found at the plant. The Japanese government failed to issue prior notices on the action to the international community properly, drawing criticism from neighbouring nations such as South Korea and Russia. The video below was broadcast on 05.04.11
A recent article has emerged in the Japanese media that would suggest both Tepco and the Japanese government were informed of the severity of the unfolding situation at Fukushima Daiichi. In late march Haruki Madarame, chairman of the Japanese Nuclear Safety Commission had contacted both Tepco and the Government that the commission had recognised that a meltdown had taken place in reactors 1-2 and 3. On the 17th of May Haruki Madarame, chairman of the Nuclear Safety Commission, said in a news conference that the meltdowns should not come as a surprise to Tepco or the Government.
“When highly contaminated water was found at the No. 2 reactor building in late March, we recognized that a meltdown had taken place. So I informed the government,” he said. “As for No. 1 and No. 3 reactors, we recognized that, given the processes that led to the accidents there, the same thing had occurred.”
Reports in the Japanese media have indicated 4 workers have begun an inspection of the Reactor No2 building of the Fukushima Daiichi nuclear power plant. To ensure the safety of the inspection team each member will be equipped with a tungsten vest to prevent external radiation exposure. They will also carry oxygen tanks on them. It is the first time workers have attempted to enter the reactor building since March 15 when there was an explosion in the reactors Suppression Chamber. 18.05.11
“Many unexpected problems have occurred since TEPCO released the original plan in April.
A large quantity of water was found in the basement of the No.1 reactor building. Highly radioactive water was found to be leaking into the ocean from the No.3 reactor.
TEPCO told reporters that the barrier set up in the sea near the water intake of the No.3 reactor may be failing to prevent contaminated water from spreading.
The utility said it will use the mineral zeolite to remove radioactive cesium from the sea.
Workers have not been able to enter the buildings of the No.2 and No.3 reactors, making it impossible to restore their cooling functions.
In addition to these obstacles, TEPCO may also face an increase in the amount of radioactive water, highly radioactive work environments, and the possible effects of the rainy season, typhoons and aftershocks.” Source NHK
Hiroaki Koide of Kyoto University Research Reactor Institute is quoted by Mainichi Shinbun as saying that the melted core of the Reactor 1 is not just out of the Reactor Pressure Vessel but out of the Containment Vessel.
From Mainichi Shinbun, Koide’s comments only (5/16/2011):
Hiroaki Koide of Kyoto University Research Reactor Institute points out that “[TEPCO] could have foreseen the core melt at an early stage when the cooling of the reactor stopped due to the power failure. TEPCO’s assessment that the damage to the fuel was limited has turned out to be completely wrong. The disclosure of the data came too late.”
According to TEPCO, the data analysis shows that damage to the RPV is not extensive. However, Koide thinks “The RPV has been completely damaged, the melted core bore a hole at the bottom of the Containment Vessel, causing the large amount of contaminated water to leak into the ground beneath the reactor building.”
Over the last several days, evidence has emerged indicating that the situation at the Fukushima Daiichi Nuclear Power Plant was far more dire than previously recognised. The main evidence is extensive—rather than partial—melting of the nuclear fuel in three reactors in the hours after the 11 March earthquake and tsunami. […]
At first, analysts from Tokyo Electric and the government believed there was only limited damage to the fuel cores. But over the last week, a combination of robotic and human inspections has led to the conclusion that the fuel assemblies in units 1, 2, and 3 were completely exposed to the air for from over 6 hours to over 14 hours and that melting was extensive if not complete. […]