Al-Hayat

Efforts to cool a reactor in an earthquake-damaged Japanese nuclear plant is “fairly effective” because the authorities turned helicopters, fire trucks and police water cannon, the organization, its owner said Friday.

But Fukushima Daiichi complex of six nuclear reactors was a risk. radiation levels reached on Friday at 20 millisieverts per hour near the place where employees tried to restore electricity, “the largest recorded so far,” said a spokesman for TEPCO.

Radiation levels at the plant Thursday morning have been about 3.8 mSv per hour – a typical resident of a developed country receives in a year. But Japan’s Nuclear and Industrial Safety Agency said 17 of the 18 workers examined normal test on the morning of Thursday, and received a higher dose of radiation requires no medical treatment.

earthquake and tsunami last Friday caused damage to four of six reactors at the Fukushima Daiichi, located on the north coast of the Japanese island of Honshu.

Thursday efforts were concentrated on the No. 3 reactor, the only thing damaged unit containing plutonium from uranium in fuel rods. Concerns remain about the pool of spent fuel at reactor No. 4, from which the IAEA says no data water temperature has been received since Monday, and as a U.S. official said on Wednesday seemed not contain water.

“The current situation in Units 1, 2 and 3, whose nuclei were damaged, appear to be relatively stable,” said Andrew Graham, a close associate of the IAEA Director General Yukiya Amano. “Unit 4, in particular, remains a major risk to security. ”

However, a spokesman for Tokyo Electric Power said Friday that a video of the swimming pool suggest that still contained water.

Japanese military helicopters dumped tons of water on the housing of reactor No. 3, including the spent fuel pool at the plant until after midnight Thursday, TEPCO reported. Old fire trucks and police took the pipe reactor housing 3 for over an hour, and TEPCO said steam and subsequent lowered radioactivity reported progress.

Experts believe that steam escaping from the pool, which contains at least partially exposed fuel rods may be emitting radiation in the atmosphere.

In Vienna, Austria said a senior official of the International Atomic Energy Agency reporters the situation was still serious, but there had been “no material deterioration” on Thursday.

The condition of the six nuclear reactors in Fukushima Daiichi raised the possibility of a collapse of several nuclear – the nightmare scenario in which the fuel rods can be cooled and the substance of the reactor core. In the worst case, fuel may spill containment unit of radioactivity or damage and the spread of cancer-causing isotope in the air and water.

All the six reactors were shut down, but some seem in better shape than others. A spokesman for the Nuclear and Industrial Safety Agency, which oversees the operation of its nuclear plants, said Friday morning that the sea water was still being injected into the reactor vessel of the first reactor an explosion of hydrogen damage, March 12.

White smoke is coming out Friday from a hole in Unit 2 of construction, said the spokesman, who was not identified by name. In a press release, the agency said that “abnormal noise” of the suppression chamber pressure was held March 15 and the chamber pressure has dropped. The workers were displaced from the unit, if the sea water injection continues.

A power source for the cooling system of Unit 1 and 2 were to join a Friday morning, a spokesman for Tokyo Electric Power Co. said.

Unit 3 was particularly troubling. It was rejected March 14 by an explosion – described by the IAEA, which is due to a hydrogen explosion. Fog – can be steam – began to rise from the reactor building Wednesday morning. Unit 3 is also the injection of seawater, and water is sprayed into it. The pressure of the repression “has been temporarily increased from approximately 6:15 on March 17,” the statement said.

The spent fuel pool at Unit 4, top U.S. nuclear regulatory official said Wednesday was likely to dry, was found to contain water, the spokesman said. “In a video taken recently, it appears that the water is still in the pool storage of fuel rods,” he said. “So, we assume that the reactor No. 4 fuel storage pool has no water.”

However, he added, the reactor itself was emitting white smoke.

Temperatures in the pools of spent fuel from units 5 and 6, had risen slowly since it lost power. But engineers have an emergency diesel generator is connected to units 5 and 6 to cool the spent fuel pools, a spokesman for the agency for nuclear and industrial safety said Friday. The water is injected into the pools of spent fuel continued.

Spent nuclear fuel stored in pools at each of the six reactors plus a pool and a dry storage container, according to the Nuclear Energy Institute. Sixty percent of the total is in the community pool, 34% is stored in spent fuel pools of the six reactors, and the remaining 6% are stored in nine dry storage containers, he said.

“There is no security problems” in the dry storage containers. The spent fuel pools – at the top of the reactor buildings to make it easier to handle during refueling – most were filled with water of 16 feet or more above the top of the fuel rods.

“The only way to empty the pool down quickly if there is structural damage to the walls, the floor,” said the statement, stressing that the pool has no drainage and the construction of concrete and steel.

They slowly lose water evaporation, when the unit to lose power and cooling systems to stop working. But the threat is not imminent. “A rapid evaporation of water is not the case,” the publication says.

If the water level drops below the fuel, oxidant zirconium cladding could occur as a result consisting of hydrogen, they say. But the only fuel dropped in recent weeks could cause a reaction so strong, that would require a temperature of about 1000 degrees, he adds.

Zirconium melts at 1600 ° C.

“The likelihood of damage caused by the clothing of the hydrogen production decreases with the temperature and cooling time,” he said. He called the prospect of a zirconium fire is “almost impossible”.

TEPCO spokesman said the water level in the main pool, which contained more fuel than it had cooled and was only 10 to 15 centimeters below normal. However, he acknowledged, officials were unable to measure the temperature there.

And nuclear engineer Arnie Gundersen told CNN that the effort will probably be maintained “for months if not years.”

“What’s pushing the fire back is the radiation leaving the spent fuel pool,” he said. If the spent fuel rods in the outdoor pool, “There are a lot of gamma rays that flood the site, forcing workers to say next.”

Four helicopter water drops on Thursday morning, a bit ‘of water seemed to affect the construction of reactor No. 3. Videos NHK showed that only one of the loads seemed to fall directly to the building. NHK reported that the floors of two helicopters used in the drops was coated with tungsten to avoid the radiation and the protection used by pilots.

Rebecca Johnson, founder of the London-based Acronym Institute for Disarmament Diplomacy, which promotes international security, disarmament and arms control, told CNN that the Japanese engineers have been “flying by the seat of your pants right now … All you are trying to problem. ‘s focus on the reactors and spent nuclear fuel is damaged, “said Johnson. “They just come to get water there, keep pumping.”

Public health officials say the release of radiation from a crisis can cause immediate health problems and long term, including radiation poisoning and cancer. Approximately 200,000 people live in a 20 km (12 miles) from the plant were evacuated, those living 20 to 30 km away were told to stay inside, and Japan has banned flights over the area.

Tests in the city of Fukushima, about 80 km (50 miles) from the factory, took radiation measurements above the average reading, but still well below levels considered harmful to humans. Small and harmless amounts of iodine – a byproduct of a potential nuclear disaster – have been found in tap water.

Citing officials Fukushima prefecture, Kyodo News reported Thursday that 10,000 people had been selected for the exhibition of the previous day in the evacuation centers and medical services.

Several countries including the United States, have demanded greater security for the area, inviting people who live in the 80 km of the factory to evacuate or stay indoors.

It is known that the winds are blowing in the northwest to help push the radiation from the sea. Still, at least 20 people fell ill due to contamination by radiation, as well as 19 wounded and two missing plant according to the IAEA.