# 5398
Maps of Nuclear Power Reactors: JAPAN
The International Atomic Energy Agency (IAEA) has released a pair of statements in the past 3 hours on the rapidly evolving situation in Japan. Both concern radiation threats coming from the Fukushima Daiichi facility in the wake of the 9.0 magnitude earthquake that struck on Friday.
This first update gives us some details on the fire at the spent fuel storage pond at reactor # 4, and the explosion at reactor #2.
The follow up SITREP informs us that the fire at the #4 site has been put out.
Japan Earthquake Update (15 March 2011, 05:15 UTC)
by International Atomic Energy Agency (IAEA) on Tuesday, March 15, 2011 at 2:01am
Japanese authorities informed the IAEA that there has been an explosion at the Unit 2 reactor at the Fukushima Daiichi plant. The explosion occurred at around 06:20 on 15 March local Japan time.
Japanese authorities also today informed the IAEA at 04:50 CET that the spent fuel storage pond at the Unit 4 reactor of the Fukushima Daiichi nuclear power plant is on fire and radioactivity is being released directly into the atmosphere.
Dose rates of up to 400 millisievert per hour have been reported at the site. The Japanese authorities are saying that there is a possibility that the fire was caused by a hydrogen explosion.
The IAEA is seeking further information on these developments. The IAEA continues to liaise with the Japanese authorities and is monitoring the situation as it evolves.
Japanese Earthquake Update (15 March 07:35 UTC)
by International Atomic Energy Agency (IAEA) on Tuesday, March 15, 2011 at 3:37am
Japanese authorities have confirmed that the fire at the spent fuel storage pond at the Unit 4 reactor of Fukushima Daiichi nuclear power plant was extinguished on 15 March at 02:00 UTC.
Please note that all future communications from the IAEA regarding events in Japan will use the Coordinated Universal Time (UTC) standard.
The IAEA continues to liaise with the Japanese authorities and is monitoring the situation as it evolves
The radiation reading of `up to 400 millisievert per hour’ mentioned in the first SITREP represents a major increase in the amount of radioactivity released from the nuclear facility.
Up until now, we’ve been seeing radiation reports only issued in microsieverts.
1000 microsieverts = 1 milliseivert
1000 millisieverts = 1 Sievert
Therefore 400 millisieverts = 400,000 microsieverts.
Background radiation provides us with between 1 and 2 millisieverts exposure every year.
So if you were in very close proximity to the radiation source (inside the reactor building) at the Fukushima Daiichi nuclear facility – at this emission level - you’d receive 200 times more radiation in an hour than you’d normally expect to get in a year.
Radiation levels outside the reactor building and away from the plant are considerably lower.
A little more than an hour’s exposure at 400 millisieverts is enough to induce mild to moderate radiation sickness in most individuals.
Radiation exposures above 1 Sievert (1000 milliseivert) represent a serious threat to human life. Doses above 6 Sieverts are almost universally fatal.
NHK World News has the following statement from Health Secretary Edano.
Edano: radiation high enough to affect health
Chief Cabinet Secretary Yukio Edano says the level of radiation around the quake-damaged Fukushima No.1 nuclear power plant is high enough to affect human health.
Edano told reporters on Tuesday morning that 400 millisieverts of radiation per hour had been detected around the plant's No.3 reactor building at 10:22 AM.
He cited reports claiming that it is highly likely the containment vessel at the No.2 reactor building had been damaged. He added that the No.1, No.2 and No.3 reactors are all releasing hazardous radioactive material.
The figure 400 millisieverts, or 400,000 microsieverts, is 4 times higher than the acceptable level of radiation for humans. Such levels could lead to a loss of white blood cells.
Tuesday, March 15, 2011 15:02 +0900 (JST)
