Friday, May 6, 2011

Tepco operators first enter into a reactor in Fukushima

Tepco operator workers have entered Thursday in the reactor building a nuclear plant in Fukushima (northeastern Japan), for the first time since the tsunami of March 11, which crippled the cooling systems of the plant. Tokyo Electric Power (TEPCO) has explained that to install an air purification device to absorb radioactive particles, which now makes the work to cool the reactor.

Dressed in masks, protective suits and heavy oxygen tanks, twelve Tepco operators have the task of connecting a ventilation system installed in the adjacent turbine unit, with eight pipelines. As reported by NHK Television, working in batches in groups of three and each will remain about ten minutes inside the reactor building to avoid excessive exposure to radiation.

Reactors 1, 2 and 3 of Fukushima Daiichi remained without cooling by the tsunami that flooded the floor and knocked out power on 11 March, causing a serious nuclear alarm around the world. TEPCO expects to start operating the air purifier on Thursday and run for three consecutive days, thus lowering the level of radiation and that operators can work for a longer time inside the reactor building.

It is expected that workers are exposed to three millisievert in Unit 1 of Fukushima, where on 17 April, a robot detected radioactivity of 49 millisieverts per hour. Japanese law allows emergency in Fukushima operators are exposed to 250 millisievert year. A group of workers entered the building Thursday in reactor number one nuclear plant in Fukushima Japan for the first time that a hydrogen explosion ripped the roof one day after the devastating earthquake and tsunami of March.

High levels of radiation detected within the building had stopped to repair staff entering and cooling systems to control the plant, a process that the operator Tokyo Electric Power has said it could last a year. Workers who came on Thursday, two officials of TEPCO and 10 contract workers, will spend 10 minutes in each, eight connecting ducts to fans to filter radioactive material in air, the company said.

"Groups of four will enter one by one to install the lines. They will be working in a cramped environment," TEPCO spokesman Junichi Matsumoto told a news conference. Staff will be equipped with protective suits, masks and air tanks and enter through a special tent erected at the entrance to prevent leakage of radiation.

The company said two workers had entered the building first to measure radiation and 10 continue to connect the lines. The first two were exposed to radiation about 2 millisieverts, TEPCO spokesman Yoshinori Mori. Under Japanese law, workers in nuclear plants may be exposed to more than 100 millisieverts over five years, but to address the crisis of Fukushima, the Health Ministry raised the legal limit on March 15 to 250 millisieverts in an emergency.

Inside the building was detected radiation up to 49 millisieverts per hour on April 17 when the company sent a robot inside. TEPCO also said in a report issued Thursday by the nuclear safety agency in Japan there was no possibility of another hydrogen explosion in reactor number one for the progress made in filling the containment vessel, a steel outer shell cement houses the reactor vessel with water.

The magnitude 9.0 earthquake and subsequent tsunami giant marzomató 11, about 14,800 people, left about 11,000 missing and destroyed tens of thousands of homes. Also stopped all refrigeration systems in the Fukushima plant, located 240 kilometers north of Tokyo, leading to increased leakage of radiation from the Chernobyl disaster in 1986.

People who lived within 20 miles of the plant was evacuated and is prohibited from returning to their homes because of fears about radiation levels.

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