日核泄漏等级升至最高级

日本最终将其核电泄漏事故等级调至7级,即国际核灾害等级中的最高级，和1986年的苏联切尔诺贝利核泄漏事故比肩，随着能量强劲的余震的不断发生，受损的核电厂还是情况不断，而核电泄漏受灾区域被撤离的居民则担心着该地区长期的核辐射的危害，他们认为政府没有告诉他们所有的真相，福岛核电泄流事故与切尔诺贝利事故的一个区别是，切尔诺贝利坐落在欧洲人口众多的区域，而福岛核电站设置在人口相对较少的海滨。

东电星期一宣布停止其向海中倾倒‘低辐射’水的行动，主要是由于受到邻国中国和韩国的抱怨。

Japan 'raises nuclear alert to highest level'

Nuclear watchdog will escalate severity of crisis at the Daiichi plant to maximum level, equal to Chernobyl disaster. Last Modified: 12 Apr 2011 05:43

The decision to raise the severity level of the nuclear crisis came as a fresh earthquake shook the Tokyo area [Reuters]

News reports say Japan has decided to raise the severity level of the crisis at its stricken nuclear power plant to 7 - the highest level and equal to the 1986 disaster at Chernobyl in the former Soviet Union.

Quoting sources at Japan's Nuclear and Industrial Safety Agency, Japan's nuclear safety watchdog, Kyodo News agency and public broadcaster NHK both said on Tuesday that NISA would raise the severity level of the nuclear radiation disaster at the Fukushima Daiichi plant to 7 from the current 5.

Minoru Oogoda, a NISA spokesman, declined to confirm the reports.

The reports came as a strong earthquake with a preliminary magnitude of 6.3 jolted the Tokyo area and its surrounding areas. Japan's Meteorological Agency said the quake struck at 8:08am local time [23:08 GMT] on Tuesday.

There were no initial reports of injuries or damage in the Tokyo prefecture. No tsunami warning was issued. But the Tokyo Electric Power Co (TEPCO), the Fukushima Daiichi nuclear plant's operator, said a fire had briefly broken out at No. 4 reactor.

TEPCO said the fire at a box that contained batteries in a building near the reactor was discovered at about 6:38am and put out seven minutes later. It was not clear whether the fire was related to Tuesday morning's earthquake. The cause was being investigated.

Earlier, the government expanded an evacuation zone around the Fukushima plant because of the high levels of accumulated radiation since a tsunami hit the complex a month ago, causing massive damage to its reactors.

Two additional quakes early afternoon on Tuesday prompted TEPCO to once again order workers to evacuate the nuclear plant. A company spokesman told Reuters news agency that the status of the damaged plant is being inspected, but did not provide additional details.

Long-term impact

Al Jazeera's Harry Fawcett, reporting from Mizusawa on Tuesday, said many Japanese are very concerned about the long-term impact of the radiation in the areas surrounding the site.

"Certainly the refugees, or the people who've been evacuated ... they've often being saying to us they're not sure they're being told the full story," he said. "The impact is certainly spreading."

Kyodo said the government's Nuclear Safety Commission had estimated that at one stage the amount of radioactive material released from the reactors in northern Japan had reached 10,000 terabequerels per hour for several hours, which would classify the incident as a major accident according to the INES scale.

The International Nuclear and Radiological Event Scale (INES), published by the International Atomic Energy Agency, ranks nuclear incidents by severity from 1 to a maximum of 7. Kyodo did not say when the big increase in radiation had happened but quoted the commission as saying the release had since fallen to under one terabecquerel per hour. The commission also released a preliminary calculation for the cumulative amount of external exposure to radiation, saying it exceeded the yearly limit of one millisieverts in areas extending more than 60km to the northwest of the plant and about 40km to the south-southwest. Jasmina Vujic, professor of nuclear engineering at University of California, Berkeley, said that there were major differences between the Chernobyl and Fukoshima disasters. Chernobyl was situated in an area with a high population density in the centre of Europe, she said, while the Japanese plant is in a lightly populated, coastal region. "From that point of view, the impact on environment and population, would be much smaller than Chernobyl," Vujic told Al Jazeera. Japan had previously assessed the accident at reactors operated by TEPCO at level 5, the same level as the Three Mile Island accident in the US in 1979. The tsunami was triggered by a 9.0 magnitude earthquake on March 11, the largest recorded in quake-prone Japan, crippling the reactors' cooling systems. Discharges stopped TEPCO said on Monday it had stopped the discharges of low-level radioactive water into the sea that have drawn complaints from neighbouring China and South Korea. It has already pumped 10,400 tonnes of low-level radioactive water into the ocean to free up storage capacity for highly contaminated water from the reactors. On Monday, shortly after Japan marked one month since the quake, a huge aftershock shook a wide swathe of eastern Japan, killing two people, and knocking out power to 220,000 homes. It was one of more than 400 aftershocks above a 5 magnitude to have hit the area since March 11. Because of accumulated radiation contamination, the government is encouraging people to leave certain areas beyond its 20km exclusion zone around the plant. Thousands of people could be affected by the move. Masataka Shimizu, TEPCO's president, visited the area on Monday for the first time since the disaster. He had all but vanished from public view apart from a brief apology shortly after the crisis began and has spent some of the time since in hospital.

Source: Al Jazeera and agencies