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Nuclear Energy Institute Report on Japan’s Nuclear Reactors, April 12, 2011 (11:30 AM EDT)


Washington, D.C.–(ENEWSPF)–April 12, 2011 – UPDATE AS OF 11:30 A.M. EDT.  Tokyo Electric Power Co. (TEPCO) is planning to pump highly radioactive water from reactor 2 into a condenser, as the utility works to control radiation and restore cooling systems at the Fukushima Daiichi nuclear power plant.

TEPCO continues to inject cooling water into reactors 1, 2 and 3 and to spray water into the used fuel pools for reactors 1-4. TEPCO also continues injection of nitrogen gas into the containment vessel of reactor 1 to prevent a possible explosion of hydrogen that may be accumulating inside.

A fire that broke out early Tuesday at a distribution switchboard near the south water discharge channel for reactors 1-4 was extinguished without interruption of reactor cooling operations or the release of radioactivity, TEPCO said.

The crisis rating of the Fukushima Daiichi accident was raised from 5 to 7 on the seven-level International Nuclear and Radiological Event Scale by the Japan Nuclear and Industrial Safety Agency. The new level, the highest on the scale, designates Fukushima as a “major accident.” The new rating puts the Japanese incident on the same level as the 1986 Chernobyl accident—even though Japanese authorities estimate that radiation released at Fukushima is only 10 percent of the amount released from the Ukrainian plant.

Authorities said much of the high-level radiation leaked from reactor 2 on March 15 and 16, early in the accident. Abnormalities in the reactor’s suppression pool caused the radiation release, the Japan Nuclear Safety Commission said. Radiation continues to leak from the suppression pool, the commission said, but the volume has dropped considerably.

UPDATE AS OF 8:30 A.M. EDT, TUESDAY, APRIL 12:
Japan’s nuclear safety agency has raised the crisis level of the Fukushima Daiichi accident from 5 to 7 on the seven-level International Nuclear and Radiological Event Scale. The new rating puts the Japanese incident on the same level as the 1986 Chernobyl accident—even though Japanese authorities estimate that radiation released at Fukushima is only 10 percent of the amount released from the Ukrainian plant.

The new level designates Fukushima as a “major accident,” up from an “accident with wider consequences.” Level 7, the highest on the scale, describes an event with “a major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures,” according to the International Atomic Energy Agency, which sponsors the ratings.

For the new rating, the Japan Nuclear and Industrial Safety Agency combined the accidents at reactors 1, 2 and 3 as a single event. Previously, separate level 5 ratings had been applied to each reactor. The earlier level 3 rating (“serious incident”) still applies to reactor 4.

Japanese authorities may revise the INES rating at the power plant as more information becomes available.

Source: nei.org


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