Search This Blog

Wednesday, March 23, 2011

IAEA : Fukushima Nuclear Accident Update Log

From IAEA, its a long update but it has the exact information needed, excerpt :

" Fukushima Daiichi Nuclear Accident Update (22 March 23:15 UTC)

Unit 2

Coolant within Unit 2 is covering about half of the fuel rods in the reactor, and Japanese authorities believe the core has been damaged. Following an explosion on 15 March, Japanese officials expressed concerns that the reactor’s containment may not be fully intact. As of 19 March, 11:30 UTC, officials could no longer confirm seeing white smoke coming from the building. Smoke had been observed emerging from the reactor earlier. White smoke/vapour was observed again from 9:22 UTC on March 21 and diminished to nearly invisible by 22:11 UTC the same day. During the time of smoke emission, an increase in radiation dose rates was reported at 9:30 UTC 21 March. TEPCO then ordered an evacuation of plant personnel, though workers returned as of 00:00 UTC 22 March.

Efforts to pump seawater into the reactor core are continuing.

On 20 March, workers began pumping 40 tonnes of seawater into the spent fuel pool. Spent fuel temperature remains relatively stable with readings between 49 and 53°.

Restoration work to return power to all units continues, with progress at Unit 2 the most advanced. A distribution panel (power center) of Unit 2 has been connected to off-site electricity supply, and individual components in the unit are being checked prior to being energized.

On 18 March, Japan assigned an INES rating of 5 to this unit.

Unit 3

Coolant within Unit 3 is covering about half of the fuel rods in the reactor, and Japanese authorities believe the core has been damaged. High pressure within the reactor’s containment led operators to vent gas from the containment. Later, an explosion destroyed the outer shell of the reactor building above the containment on 14 March. Indicated containment pressure has stabilized over the past 24 hours.

Following the explosion, Japanese officials expressed concerns that the reactor’s containment may not be fully intact. White smoke has been seen emerging from the reactor, but on 19 March it appeared to be less intense than in previous days. Grey smoke was observed on 21 March in the southeast corner of Unit 3 from 6:55 UTC. After two hours this smoke turned to a white color and gradually diminished. By 22:11 21 March, the smoke was observed to be �ceasing.’ As reported under the Unit 2 update, during the time of smoke emission, an increase in radiation dose rates was reported at 9:30 UTC 21 March. TEPCO then ordered an evacuation of plant personnel, though workers returned as of 00:00 UTC 22 March."

No comments:

Post a Comment