IAEA To Send Fact Finding Mission To Fukushima

 

# 5558

 

 

The UN’s Atomic Energy Agency (IAEA) will dispatch an expert fact-finding mission to Japan on May 24th to  make a preliminary assessment of nuclear safety issues at the Fukushima Daiichi nuclear power plant following the March 11th earthquake and Tsunami.

 

The press announcement reads:

 

Press Release 2011/06

IAEA Sends International Fact-finding Expert Mission to Japan

17 May 2011 | The International Atomic Energy Agency will dispatch an international expert fact-finding mission to Japan.

 

Based upon the agreement between the IAEA and the Government of Japan, the mission, comprising nearly 20 international and IAEA experts from a dozen countries, will visit Japan between 24 May and 2 June 2011. Under the leadership of Mr. Mike Weightman, HM Chief Inspector of Nuclear Installations of the United Kingdom, the mission will conduct fact-finding activities at Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Station (NPS) site and in other locations.

 

The expert mission will make a preliminary assessment of the safety issues linked with TEPCO's Fukushima Dai-ichi NPS accident following the Great East Japan Earthquake and Tsunami. During the mission, areas that need further exploration or assessment based on the IAEA safety standards will also be identified.

 

In the course of the IAEA mission, the international experts will become acquainted with the Japanese lessons learned from the accident and will share their experience and expertise in their fields of competence with the Japanese authorities.

 

Mr. Weightman will present the mission's report at the Ministerial Conference on Nuclear Safety organised by the IAEA in Vienna from 20 to 24 June 2011, as an important input in the process of reviewing and strengthening the global nuclear safety framework that will be launched by the Conference.

 

Updates on the situation at the damaged Fukushima facility are coming less frequently from the IAEA, with the last one issued on Friday May 13th.

 

IAEA Briefing on Fukushima Nuclear Accident (4 - 11 May 2011, 17:00 UTC)

by International Atomic Energy Agency (IAEA) on Friday, May 13, 2011 at 12:27pm

On Friday, 13 May 2011, the IAEA provided the following information on the status of nuclear safety in Japan:

1. Emergency at Fukushima Daiichi Nuclear Power Plant

Overall, the situation at the Fukushima Daiichi nuclear power plant remains very serious.

(Continue . . . )

 

 

Each day, however, seems to bring new revelations on the extent of the damage to the fuel rods at the damaged reactors and revised plans to rectify the crisis.

 

The following report comes from the Voice Of America.

 

 

Japan Revises Plan to Bring Fukushima Reactors Under Control

Martyn Williams | Tokyo  May 17, 2011

Photo: Reuters

Workers are seen near cable trench pit for the water intake of No.2 reactor at Tokyo Electric Power (TEPCO) Co.'s Fukushima Daiichi Nuclear Power Station in Fukushima prefecture in this handout photo released by TEPCO on May 17, 2011

Tokyo Electric will step up measures to prevent groundwater contamination at the stricken Fukushima nuclear-power plant amid worries that highly radioactive water is leaking from the core of at least one reactor.

 

Company officials say work will begin immediately to build a drainage system that will pump the water to a reprocessing facility where much of the radioactivity can be removed. It will then be re-circulated through the cooling system.

 

Recent data analysis concluded a meltdown of nuclear fuel likely occurred within a day of the March 11 earthquake and tsunami that devastated the region. The melted fuel is thought to have created holes allowing water to leak from the center of the reactor.

 

The work is one of the new measures in Tokyo Electric's plan for taking the Fukushima Daiichi plant from crisis to stability. Other measures will be visually apparent at the plant in the coming months.

(Continue . . . )

 

 

That more than two months later the story continues to evolve regarding the hours and days immediately following the disaster should come as no great surprise.

 

As I wrote in The Fog Of Disaster Reporting, two days after the earthquake struck:

 

Early reports from the ground during any major disaster are usually fragmentary, often misleading, and occasionally just downright wrong.

 

Over the past 60 days, we’ve seen our share of `erroneous’ reports.

 

Obviously, it is important to learn exactly what happened at Fukushima, what responses were mounted, and what worked . . .  and what didn’t.

 

While one always hopes another disaster of this sort never happens, there are lessons to be learned here. Particularly from the things that did not work as planned.

 

Lessons that could save lives the next time the `unthinkable’ happens.

IAEA Briefing On Fukushima Severity Level

 

# 5486

 

 

 

The International Atomic Energy Agency (IAEA) released an update over the last few hours on the revision to the Fukushima severity level I reported last night (see Fukushima: Brief Fire, 6.4 Aftershock & Severity Level To Be Raised).

 

While sharing the same severity level as Chernobyl, Japan’s Nuclear and Industrial Safety Agency (NISA) is quick to point out that the amount of radiation released from Fukushima is estimated to be 1/10th that of the Russian disaster.

 

 

NISA, however, has come under increasing criticism for its handling of the disaster and the speed in which it has released radiation readings from the reactor facilities and surrounding areas.

 

There have been frequent calls from the public, international agencies, and world governments for better dissemination of information on the nuclear crisis (including Kyoto News China urges Japan to release timely, precise info on nuke crisis).

 

Yesterday NISA publicly admitted that their actions have not always been adequate for the task at hand (see NHK News Nuclear safety regrets its response to Fukushima).

 

Events and admissions that are likely to do little to assuage criticism and frustration over NISA’s ongoing assessment and handling of the nuclear risks at Fukushima.

 

Here is the IAEA update, followed by links to the NISA announcement.

 

 

 

IAEA Update on Fukushima Nuclear Accident (12 April 2011, 4:45 UTC)

by International Atomic Energy Agency (IAEA) on Tuesday, April 12, 2011 at 12:43am

The Japanese Nuclear and Industrial Safety Agency (NISA) today issued a new provisional rating for the accident at the Fukushima Daiichi nuclear power plant on the IAEA International Nuclear and Radiological Event Scale (INES).

 

The nuclear accident at Fukushima Daiichi is now rated as a level 7 "Major Accident" on INES. Level 7 is the most serious level on INES and is used to describe an event comprised of "A major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures." Japanese authorities notified the IAEA in advance of the public announcement and the formal submission of the new provisional rating.

 

The new provisional rating considers the accidents that occurred at Units 1, 2 and 3 as a single event on INES. Previously, separate INES Level 5 ratings had been applied for Units 1, 2 and 3. The provisional INES Level 3 rating assigned for Unit 4 still applies.

 

The re-evaluation of the Fukushima Daiichi provisional INES rating resulted from an estimate of the total amount of radioactivity released to the environment from the nuclear plant. NISA estimates that the amount of radioactive material released to the atmosphere is approximately 10 percent of the 1986 Chernobyl accident, which is the only other nuclear accident to have been rated a Level 7 event.

 

Earlier ratings of the nuclear accident at Fukushima Daiichi were assessed as follows:

 

On 18 March, Japanese authorities rated the core damage at the Fukushima Daiichi 1, 2 and 3 reactor Units caused by loss of all cooling function to have been at Level 5 on the INES scale. They further assessed that the loss of cooling and water supplying functions in the spent fuel pool of the Unit 4 reactor to have been rated at Level 3.

 

Japanese authorities may revise the INES rating at the Fukushima Daiichi nuclear power plant as further information becomes available.

 

INES is used to promptly and consistently communicate to the public the safety significance of events associated with sources of radiation. The scale runs from 0 (deviation) to 7 (major accident).

 

For further information on the INES scale:

http://www-ns.iaea.org/tech-areas/emergency/ines.asp

Further details regarding this development can be found in the following NISA press release:

http://www.nisa.meti.go.jp/english/files/en20110412-4.pdf

IAEA Fukushima Briefing: April 10th

 

 

# 5480

 

The IAEA (International Atomic Energy Agency) has just released their latest briefing, giving the status of the damaged reactors at the Fukushima Daiichi facility.

 

I’ve only reproduced the first section of a much longer report, follow the link to read it in its entirety.

 

 

IAEA Briefing on Fukushima Nuclear Accident (10 April 2011, 15:00 UTC)

 

by International Atomic Energy Agency (IAEA) on Sunday, April 10, 2011 at 8:30am

 1. Current Situation

Earthquake of 7^th April

External power has been restored at all sites affected by the 7^th April earthquake.  The 3 litres of water that were spilled at Onagawa NPP have been cleaned up.

 

Changes to Fukushima Daiichi Plant Status

Overall, the situation at the Fukushima Daiichi plant remains very serious but there are early signs of recovery in some functions such as electrical power and instrumentation.

 

In Units 1, 2 and 3, 60,000 tons of contaminated water need to be removed from the turbine buildings and trenches. This water will be transferred to the condensers of each unit and the Radioactive Waste Treatment facility. In addition, temporary storage tanks have been ordered to provide additional capacity for the water and will be located adjacent to the Radioactive Waste Treatment facility. In Unit 2 water transfer from the condenser to the condensate storage tank was completed on 9^th April.

 

Nitrogen gas is being injected into the Unit 1 containment vessel to reduce the possibility of hydrogen combustion within the containment vessel. The pressure in this containment vessel is increasing due to the addition of nitrogen.

 

In Unit 1 fresh water is being continuously injected into the reactor pressure vessel through feed-water line at an indicated flow rate of 6 m³/h using a temporary electric pump with off-site power. In Units 2 and 3 fresh water is being continuously injected through the fire extinguisher lines at indicated rates of 7 m³/h and 7 m³/h respectively using temporary electric pumps with off-site power.

 

In Unit 1 the pressure in the RPV is increasing as indicated on both channels of instrumentation. NISA has indicated that some instruments in the reactor vessel may not be working properly. In Units 2 and 3 Reactor Pressure Vessel and Drywell pressures remain at atmospheric pressure.

 

RPV temperatures remain above cold shutdown conditions, typically less than 95°C.  In Unit 1 temperature at the feed water nozzle of the RPV is 235°C and at the bottom of the RPV is 120°C. In Unit 2 the temperature at the feed water nozzle of the RPV is 145°C. The temperature at the bottom of the RPV was not reported. In Unit 3 the temperature at the feed water nozzle of the RPV is 97°C and at the bottom of the RPV is 109°C.

 

The concrete pump vehicle sprayed fresh water (90 T) to the spent fuel pool in Unit 4 on 9^th April.

There has been no change in status in Units 4,  5 and 6 and the Common Spent Fuel Storage Facility

(Continue . . . )

 

 

You can also view the SUMMARY OF REACTOR STATUS report HERE.

 

(Click to view)

Japan: IAEA Briefing April 8th

 

 

# 5477

 

 

In the wake of a 7.1 magnitude aftershock yesterday, the IAEA has issued a new briefing that includes status updates on several other nuclear reactors in northern Japan.

 

Yesterday’s temblor was the largest aftershock yet since the March 11th 9.0 quake that generated a massive tsunami, devastated northern Japan, and severely damaged several nuclear reactors.

 

The IAEA continues to categorize the status of these damaged reactors by stating: 

 

Overall, the situation at the Fukushima Daiichi plant remains very serious although there are early signs of recovery in some functions such as electrical power and instrumentation.

 

I’ve only reproduced the opening section which pertains to this latest aftershock’s effects on Japan’s nuclear facilities. 

 

Follow the link to read this update in its entirety.

 

 

IAEA Briefing on Fukushima Nuclear Accident (8 April 2011, 15:00 UTC)

by International Atomic Energy Agency (IAEA) on Friday, April 8, 2011 at 10:57am

1.      Earthquake of 7th April

The IAEA confirms that an earthquake occurred in Japan at 14:32 UTC 7th April. The IAEA International Seismic Safety Centre has rated it as a 7.1 magnitude, revised from an initial 7.4 magnitude.

The epicenter of the earthquake was 20 km from the Onagawa nuclear power plant and approximately 120 km from the Fukushima Daiichi and Daini nuclear power plants.

 

The IAEA has been in contact with NISA and can confirm the status of the following nuclear facilities:

Fukushima Daiichi NPP

No changes have been observed at the on-site radiation monitoring posts. The injection of water into the reactor pressure vessels of Units 1, 2 and 3 was not interrupted.

Fukushima Daini NPP

No changes have been observed of the readings at the on-site radiation monitoring posts.

Onagawa NPP

All reactors have been in cold shutdown since the 11th March earthquake.

 

Two out of the three lines supplying off-site power to the site were lost following the 7th April earthquake. Off-site power continues to be supplied through the third line.

 

Cooling of the spent fuel pool was temporarily lost, but has subsequently been restored.

 

No change has been observed in the readings from the on-site radiation monitoring post. The status of the plant is currently being checked.

Tokai Daini NPP

Tokai Daini nuclear power plant remains in cold shutdown since the 11th March earthquake. No abnormality has been observed.

Higashidori NPP

The Higashidori NPP was shut down and in a maintenance outage at the time of the 7th April earthquake. Off-site power was lost temporarily. Emergency power supply to the site operated as expected until off-site power was restored. All the fuel had been removed from the reactor core and stored in the spent fuel pool. Cooling of the spent fuel pool is operational.

Tomari NPP (in Hokkaido)

At the time of the 7th April earthquake Tomari Unit 1 and Unit 2 were in operation. Following the 7th April earthquake, the Hokkaido Electric Power Company reduced the generating power to 90% of capacity.

Rokkasho Reprocessing Plant

Rokkasho Reprocessing Plant and uranium enrichment facility lost off-site power. Emergency power supply to the site is operating.

(Continue . . . )

 

 

 

Seismologists warn that additional strong aftershocks are still possible over the next few weeks and months.

The IAEA Presentations Channel

 

 

# 5451

 

 

The International Atomic Energy Agency (IAEA) has selected Slideshare to host documentation, slide shows, and other presentations on the Japanese nuclear crisis. 

 

You can access (as of this writing) 26 presentations, and 6 documents at the IAEA Presentations Channel.

 

 

 

Some of these are multi-slide presentations while others are informative single page charts and graphics, like the one below:

 

 

A resource very much worth checking every day or so.

Fukushima IAEA Updates: March 24th

 

 

# 5441

 

 

The IAEA has posted as series of updates on the Fukushima nuclear reactors on their website and their Facebook Page.

 

 

You can view the most recent updates at:

Fukushima Nuclear Accident Update Log

 

Table: Summary of reactor unit status at of 24 March-0600 UTC

 

 

 

 

Fukushima Daiichi Nuclear Accident Update (24 March, 17:30 UTC)

Japanese Seawater Samples Show Signs of Radioactive Materials

Japanese authorities today provided the IAEA with data on seawater samples they collected on 22 and 23 March, after detecting iodine and cesium in the water near the Fukushima Daiichi nuclear power plant. (See earlier update.)

 

A vessel from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) collected water samples at several points 30 kilometres from the coastline and found measurable concentrations of iodine-131 and cesium-137.

The iodine concentrations were at or above Japanese regulatory limits, and the cesium levels were well below those limits.

 

The IAEA's Marine Environmental Laboratory in Monaco has received the data for review.

 

Fukushima Daiichi Nuclear Accident Update (24 March 17:25 UTC)

Japanese Workers Treated for Radiation Exposure

Japanese authorities today reported that three workers at the Fukushima Daiichi nuclear power plant were exposed to elevated levels of radiation. The three were working in the turbine building of reactor Unit 3 and have received a radiation dose in the range of 170-180 millisieverts.

Two of the workers have been hospitalized for treatment of severely contaminated feet, which may have suffered radiation burns. The workers had been working for about three hours in contact with contaminated water.

 

Fukushima Daiichi Nuclear Accident Update (24 March 2011, 14:00 UTC)

by International Atomic Energy Agency (IAEA) on Thursday, March 24, 2011 at 10:29am

Spent Fuel Pools at Fukushima Daiichi Nuclear Power Plant - Updated

Spent fuel removed from a nuclear reactor is highly radioactive and generates heat. This irradiated fuel needs to be stored for one to three years in pools that cool the fuel, shield the radioactivity, and keep the fuel in the proper position to avoid fission reactions. If the cooling is lost, the water can boil and fuel rods can be exposed to the air, possibly leading to severe damage and a large release of radioactive materials.

 

Nuclear power plants must replace fuel every one to two years, and the Fukushima Daiichi reactors typically remove about 25 percent of the reactor's fuel -- to be replaced with fresh, or unirradiated, fuel -- during each refuelling outage. The spent fuel, which is hottest immediately after it is removed from the reactor, is placed in the spent fuel pool until it is cool enough to be moved to longer-term storage.

 

The concern about the spent fuel pools at Fukushima Daiichi is that the capability to cool the pools has been compromised. See diagram below for location of the pool in each reactor building.

For more, see...http://www.iaea.org/newscenter/news/tsunamiupdate01.html

 

IAEA Update: The 6 Fukushima Reactors At A Glance

 

 

# 5425

 

 

With 6 separate reactors at the earthquake damaged Fukushima nuclear facility in Japan, and with each experiencing different levels of damage and concerns, keeping their statuses straight based on text reporting has always been tough. 

 

The IAEA helps out with this handy reference chart that shows at a glance the status and color-coded level of concern in a variety of categories for each reactor.

 

(Click image to Enlarge)

 

The above graphic appears as part of a lengthy IAEA report released yesterday, updating the situation at the Fukushima facility.  

 

You’ll find a brief excerpt below, but follow the link to read it in its entirety.

 

Japan Earthquake Update (20 March 2011, 21:00 UTC)

(Excerpt)

IAEA Briefing on Fukushima Nuclear Emergency (20 March 2011, 15.30 UTC)

On Sunday, 20 March 2011, Graham Andrew, Special Adviser to the IAEA Director General on Scientific and Technical Affairs, briefed both Member States and the media on the current status of nuclear safety in Japan. His opening remarks, which he delivered at 15:30 UTC at the IAEA headquarters in Vienna, are provided below:

1. Current Situation

 

There have been some positive developments in the last 24 hours, but the overall situation at the Fukushima Daiichi nuclear power plant remains very serious.

 

Efforts to restore electrical power to the site continue. Off-site electrical power has been connected to the local substation for Unit 2 today. Work is continuing under difficult conditions to connect power from the substation to the reactor building. Seawater is still being injected into the reactor pressure vessels of Units 1, 2 and 3. Water injection is not needed for Unit 4 as the reactor is in outage.

 

White smoke or vapour from Unit 3 is still being observed, but it is less intense than on previous days. Spraying of the reactor building with water is in progress.

 

Following an initial rise in pressure in the Unit 3 reactor pressure vessel, plans were made to vent the vessel should it become necessary. However, from information recently provided by NISA they have decided not to vent as the vessel pressure has started to reduce.

 

The situation in the reactor spent fuel pools is relatively stable, but is still of concern. Spraying of water into the pool of Unit 4 started yesterday. The Agency still lacks data on water levels and temperatures at the spent fuel pools at Units 1, 2, 3 and 4.

 

A positive development is that cooling has been restored to the reactor pressure vessels in Units 5 and 6. Temperatures in the spent fuel pools at these two units, which had been rising in the last few days, have now fallen significantly to around 40 degrees centigrade from a maximum of about 69 degrees yesterday. Two diesel generators, one for each Unit, are providing electricity.

(Continue . . .)

IAEA Update (March 17th) On Japan’s Nukes

 

 

# 5415

 

We’ve a fresh IAEA briefing on the status of the damaged and overheating nuclear reactors in Japan this evening.

 

Along with that we have a brief update on the progress that TEPCO is making towards bringing a high voltage power line to the plant, to (hopefully) run the coolant pumps.

 

 

The money quote from all of it seems to be:

 

The situation at the Fukushima Daiichi nuclear power plants remains very serious, but there has been no significant worsening since yesterday.

 

First, notes on an IAEA Briefing that was posted just around 2030hrs EDT.

 

IAEA Briefing on Fukushima Nuclear Emergency (17 March 2011, 14:00 UTC)

by International Atomic Energy Agency (IAEA) on Thursday, March 17, 2011 at 8:31pm

At the IAEA headquarters in Vienna, Graham Andrew, Special Adviser to the IAEA Director General on Scientific and Technical Affairs, briefed both Member States and the media on the current status of nuclear safety in Japan.

Current Situation

The situation at the Fukushima Daiichi nuclear power plants remains very serious, but there has been no significant worsening since yesterday.

 

The current situation at Units 1, 2 and 3, whose cores have suffered damage, appears to be relatively stable. Sea water is being injected into all three units using fire extinguishing hoses. Containment pressures are fluctuating.

 

Military helicopters carried out four water drops over Unit 3.

 

Unit 4 remains a major safety concern. No information is available on the level of water in the spent fuel pool. No water temperature indication from the Unit 4 spent fuel pool has been received since 14 March, when the temperature was 84 °C. No roof is in place.

 

The water levels in the reactor pressure vessels of Units 5 and 6 have been declining.

 

Radiation Monitoring

We are now receiving dose rate information from 47 Japanese cities regularly. This is a positive development. In Tokyo, there has been no significant change in radiation levels since yesterday. They remain well below levels which are dangerous to human health.

 

As far as on-site radiation levels at the Fukushima Daiichi and Daini nuclear power plants are concerned, we have received no new information since the last report.

 

In some locations at around 30 km from the Fukushima plant, the dose rates rose significantly in the last 24 hours (in one location from 80 to 170 microsievert per hour and in another from 26 to 95 microsievert per hour). But this was not the case at all locations at this distance from the plants.

 

Dose rates to the north-west of the nuclear power plants, were observed in the range 3 to 170 microsievert per hour, with the higher levels observed around 30 km from the plant.

 

Dose rates in other directions are in the 1 to 5 microsievert per hour range.

(Continue . . . )

 

Next, the update on work to the bring external power to the Fukushima nuclear plant.

 

 

Japan Earthquake Update (17 March 2011, 16:55 UTC) - CLARIFIED

by International Atomic Energy Agency (IAEA) on Thursday, March 17, 2011 at 8:33pm

Japanese authorities have informed the IAEA that engineers have begun to lay an external grid power line cable to Unit 2. The operation was continuing as of 20:30 UTC, Tokyo Electric Power Company officials told the Nuclear and Industrial Safety Agency.

 

They plan to reconnect power to Unit 2 once the spraying of water on the Unit 3 reactor building is completed.

 

The spraying of water on the Unit 3 reactor building was temporarily stopped at 11:09 UTC (20:09 local time) of 17 March.

 

The IAEA continues to liaise with the Japanese authorities and is monitoring the situation as it evolves.

 

These reports, while helpful, leave an awful lot of important questions unanswered. 

 

Of particular concern: radiation readings at or near the plant don’t seem to be available, nor are the water level and temperature readings on reactor #4.

 

It may be that sensors are inoperable, and this data just isn’t available. 

 

But there is a a growing frustration among reporters, outside agencies, and governments around the world over the tepid flow of information from Japanese officials on this ongoing crisis. 

Japan: Radiation Readings & Two IAEA Updates

 

 

 

# 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)