Fresh water pumped into reactor at Japan nuclear plantTokyo, March 26, 2011
The operator of a stricken nuclear power plant in north-eastern Japan started Saturday to inject fresh water into an overheating reactor.
The operator, Tokyo Electric Power Co. (TEPCO), started pumping water into reactor 2 at Fukushima 1 nuclear power plant as workers tried to restore light and power to the control room in their efforts to get the reactor’s cooling system operational. The plant was damaged by the March 11 earthquake and resulting tsunami.
Radiation-contaminated water has been found near four of its reactors, which it was feared might have seeped from damaged reactor cores or spent-fuel pools.
The operator has vowed to clear the radioactive water as quickly as possible to allow workers access to the reactors as they attempt to restore the cooling systems. On Thursday, three engineers working on the cooling system at reactor 3 were exposed to radiation levels in water at 10,000 times the normal level.
Those levels suggested the vessel might have been damaged and leaked radioactive materials, Hidehirko Nishiyama, a spokesman for the government’s nuclear safety commission, told a news conference.
The three workers’ radiation exposure was believed to have been at levels amounting to 173 to 180 millisieverts.
Two of the three workers were hospitalized Thursday with beta ray radiation burns to their legs caused by direct exposure, TEPCO said.
Authorities have identified eight radioactive substances in stagnant water in the basement of part of the plant, an analysis released Saturday by the commission showed.
The highest levels found in the water in reactor 1 of the plant were of caesium 137, a radioactive isotope that was released into the environment in the Chernobyl disaster. It appeared at levels of 1.8 million becquerel.
Caesium 137, in contrast to radioactive iodine, has a relatively long half life of 30.2 years. It is created during nuclear fission.
The water also contained caesium isotopes 134 and 136 as well as iodine-131.
Seventeen workers at the plant have been diagnosed as contaminated since the plant was damaged in a March 11 earthquake and resulting tsunami. That figure includes only those who have been exposed to more than 100 millisieverts of radiation, the maximum allowed exposure for a nuclear plant worker for an entire year.
Keywords: Japan Quqake,Japan Tsunami, Fukushima Nuclear Power Plant ,Radioactive LEakage