Update (2:25pm EST):
“Tepco, the operator of the Fukushima Daiichi plant, is holding a press briefing and saying that a new power line that could solve the cooling problem at the plant is almost ready,” Guardian reports.
“No details yet but presumably that could mean the company could reconnect the reactors to the grip and so operate their usual cooling functions. Let’s wait and see.”
Japan is reconsidering try dropping water from helicopters to cool spent fuel if needed, something which was previously deemed too dangerous.
3 nuclear reactors have officially suffered core damage according to Yukiya Amano, the head of the International Atomic Energy Agency.
Update (7:44am EST): A plan to drop seawater on spent nuclear fuel from helicopters to cool it has failed (“due to high radiation”) and a new plan, firing water into the pool from a police water cannon truck, is being pursued.
Update (5:20am EST): Workers have been allowed back in to continue pumping seawater in to the reactors in an attempt to cool them.
Original Post: Only hours after we reported that between 40 and 70 nuclear engineers had remained behind at the Fukushima Daiichi nuclear power plant after the majority of staff were evacuated, reports from several major news agencies are confirming that they have since been evacuated as a result of a major radiation spike.
The operators had been working around the clock in radiated conditions in an attempt to ensure the reactors were kept from overheating by dousing them with seawater, an trying to put out a fire at one of the reactors.
“As of 10:22 a.m. on Tuesday, 30 mSv [millisievert] of radiation dose was detected between the No.2 and 3 reactors of the Fukushima nuclear plant, 400 mSv of radiation near No.3 reactor, and 100 mSv of radiation near No.4 reactor,” agencies quoted Yukio Edano, Japan’s chief cabinet secretary as saying.
Putting that in perspective, a 400 mSv dose is eight times as much as the limit radiation workers are exposed to per year.
Japan’s national public broadcasting organisation, NHK, said 965.5 mSv of radiation per hour was detected near the No.2 reactor on Tuesday morning.
Second Fire in 24 Hours
The second fire to hit the spent fuel storage pond at was reported at 5:45 a.m.(2110 GMT) by workers at the nuclear plant. The fire was pinpointed at the northwestern corner of the building’s fourth floor, however the Japanese government notified the International Atomic Energy Agency (IAEA) that the blaze could no longer be seen 30 minutes later, despite TV pictures showing smoke or steam rising from the facility.
The International Atomic Energy Agency (IAEA) said:
“Japanese authorities have informed the IAEA that a fire in the reactor building of unit 4 of the Fukushima Daiichi nuclear power plant was visually observed at (2045 GMT) … As of (2115) of the same day, the fire could no longer be observed.”
Water Levels Dropping
According to the IAEA update as of 16 March 2011, 03:55 UTC, Japanese authorities have also informed the IAEA that at 12:00 UTC of 15 March the water level in unit 5 had decreased to 201 cm above the top of the fuel. This was a 40 cm decrease since 07:00 UTC of 15 March. Officials at the plant were planning to use an operational diesel generator in unit 6 to supply water to unit 5.
Radiation Levels Increasing
According to the newspaper Kyodo, radiation levels in the Chiba prefecture, bordering the prefecture of Tokyo to its west, are currently 10 times above normal levels, though they state there is no immediate health risk.
UPDATING AS NEWS ARRIVES