Japan - Fukushima Daiichi Nuclear Power Plant Crisis - Units 1 - 6 Reports, News, Graphics - March 11 - March 16

[sharon sanders]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

machine translation -

Fukushima Daiichi Unit 4 fire disappear

12 hours 34 minutes 3 twitter tweet on May 15 (NHK clicking leaves the site)

In Unit 4 of Fukushima Daiichi Nuclear Power Station, 15 am, fire broke out at the pool to store spent nuclear fuel located in the containment, and fire is that it depends on the Tokyo Electric Power went out.

In Unit 4, as well as roof damage is found near the reactor building also has information that raised the temperature of the pool to store spent nuclear fuel, to check the status of TEPCO. According to TEPCO, in Unit 4 of Fukushima Daiichi nuclear power plant is about 38 minutes at 9:00 am, confirmed the fire started near the northwest part of the fourth floor of the reactor building. The fire is that it then disappeared. In Unit 4, before the confirmation of the fire, after the explosion, also have been found damaged near the roof on the building of the reactor, the temperature of the pool to store nuclear fuel used at the container store, that there is information that is up to the usual 40 degrees to 84 degrees. TEPCO, "in No. 4 is a hydrogen explosion believed to be more involved with the fire and do not know," I said. No. 4 over the fire, in a press conference at 11 am from the Chief Cabinet Secretary 枝野 too, "No. 4 is happening on the fire. Reactor after the earthquake has stopped, storage pool that generation of hydrogen from having the heat spent nuclear fuel is. be inferred explosion of hydrogen, such as occurred in the No. 3 and the No. 1 so far, "he said, hydrogen explosion at Reactor No. 4 shows a view that has happened.

http://www3.nhk.or.jp/news/html/20110315/t10014683071000.html

[JimO]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

This point about the spent fuel rod cooling pools is important. If fires or explosions cause those spent rods to be exposed to the air, they too could heat up to a point of releasing radioactive material. The spent rods are stored in far less secure facilities than the active fuel rods in the reactors.

[Laidback Al]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

Radiation Exposure Could Curtail Workers? Efforts

HENRY FOUNTAIN

Published: March 14, 2011

As radiation levels rise at the crippled reactors in northern Japan, a basic question arises: how long can workers keep struggling to ward off full meltdowns?

The workers are performing what have been described as heroic tasks, like using fire equipment to pump seawater into the three failing reactors to keep the nuclear fuel from melting down and fighting the fire at a fourth reactor.
. . . .

If they exceed a certain amount, they can?t go back in for a day or a week or longer,? said Dr. Lew Pepper, a professor at the Boston University School of Public Health who has studied the effects of radiation on nuclear weapons workers. And the pool of available replacements is finite, he said: ?What do you do? You don?t have a lot of people who can do this work.?
. . . .

While regulations may differ somewhat in Japan, in the United States the usual radiation exposure limit for nuclear power plant workers is 50 millisieverts, or 5 rem, per year (compared with the 0.3 rem that the Environmental Protection Agency says most people get from normal background radiation). When there is an emergency, the limit can be raised to 25 rem, which is still far below the level at which people would show symptoms or get sick.

The explosion at Fukushima?s Reactor No. 2 on Tuesday morning sent radiation levels spiking, to 8,217 microsieverts an hour from 1,941 about 40 minutes earlier.
. . . .

In Japan, the plant operators do not have the luxury of time for training. ?You need somebody who is familiar with the plant, because you need somebody to do it now,? Mr. Gundersen said.

Japanese workers might be so committed that they might be willing to exceed accepted levels of exposure.
. . . .

http://www.nytimes.com/2011/03/15/science/15workers.html?_r=1

[Sally Furniss]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

Trace amounts of radioactive material and Tokyo observation
March 15, 14:14 min.
From nuclear power plants Fukushima Daiichi, due to work to reduce the pressure of the reactor is released radioactive material around, has been observed that tiny amount of a radioactive substance in Tokyo, etc, can affect health both number of levels it's not.

More than 40 km away in Iwaki, Fukushima Daiichi nuclear power plant is at 4:00 am on June 15, and microsievert 23.72 per hour, but observe the amount of radiation equivalent to 470 times the normal 2 hours Later, about 80 times the normal hourly microsievert down to 3.94. In Tokai, Ibaraki Prefecture, 110 kilometers away over the south, 46 minutes 7:00 am, was observed for 5 microsievert hourly radiation values for the country "extraordinary situation" but the report, noon radiation dose, the trace has been microsievert 2 per hour. Both levels are affected by a number is that there is no immediate health. Kanagawa and Tokyo, Chiba, Saitama, in each prefecture of Tochigi, but observed the radiation dose to ten times the number from a few times, usually around the early morning levels can affect your health immediately None of that there is no It is. In Tokyo is that radioactive material was also observed, such as iodine and cesium. The amount of radiation per hour were measured in these regions is less than one-hundredth of the level that is acceptable bathed years ordinary people in higher numbers in the municipality of each health effects immediately any the number has not come. Miyagi, Yamagata, Akita and Aomori prefectures in the Tohoku region, Niigata Prefecture, Gunma Prefecture, the major change is that the number of radiation observed. Professor Nakagawa Keiiti the University of Tokyo specializing in medical radiation, "was thought to have leaked from a nuclear power plant in Fukushima, can be detected in the metropolitan area is not happen enough. However, the amount is so very small There is no health effects. If the current situation and reach a level they affect the future health, so unlikely, I want to worry, "I said.

http://www3.nhk.or.jp/news/html/20110315/t10014685301000.html

[Sally Furniss]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

Reactor No. 4 exploded a hydrogen or fuel rods exposed
3:17 min 3 twitter tweet on May 15 (NHK leaves the site and click)

TEPCO, at a press conference at 4:00 pm on December 15, "run out of water in the pool of spent nuclear fuel has put on the No. 4 Fukushima Daiichi Nuclear Power Station, with exposed fuel rods, a hydrogen explosion could "have stated, the cause has not yet possible to determine. And still, if there is water in the pool of spent nuclear fuel of Unit 4 has not been able to confirm. The value of measuring the radiation monitoring posts, and now 15 minutes 22:10 am, was found about the amount of 400 mSv of high radiation per hour near the No. 3 nuclear reactor building of a hydrogen explosion Some scattered, leaving is that there could be higher

http://www3.nhk.or.jp/news/html/20110315/t10014693561000.html

[Ronan Kelly]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

Press Releases

Press Release (Mar 15,2011)
Damage to the Unit 4 Nuclear Reactor Building at Fukushima Dai-ichi Nuclear Power Station


At approximately 6:00am, a loud explosion was heard from within the
power station. Afterwards, it was confirmed that the 4th floor rooftop
area of the Unit 4 Nuclear Reactor Building had sustained damage.After usage, fuel is stored in a pool designated for spent fuel.

Plant conditions as well as potential outside radiation effects are
currently under investigation.

TEPCO, along with other involved organizations, is doing its best to
contain the situation. Simultaneously, the surrounding environment is
being kept under constant surveillance.

http://www.tepco.co.jp/en/press/corp-com/release/11031504-e.html

[Ronan Kelly]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

15 March 2011 Last updated at 06:11 ET By Richard Black

Environment correspondent, BBC News

A third explosion at the site appears to have damaged reactor 2's containment
It appears that for the first time, the containment system around one of the Fukushima Daiichi reactors has been breached.

Officials have referred to a possible crack in the suppression chamber of reactor 2 - a large doughnut-shaped structure, also known as the torus, below the reactor housing.
That would allow steam, containing radioactive substances, to escape continuously.

This is the most likely source of the high radioactivity readings seen near the site.

However, an alternative possible source is the fire in reactor 4 building - believed to have started when a pool storing old fuel rods dried up.

When fuel rods reach the end of their useful life and are taken from the reactor, they still contain a lot of radioactive nuclei, which means they get hot.

Typically they will be placed in an indoor pond looking rather like a swimming pool, and can be kept there for decades before being sent for reprocessing or dry storage.

Without an inflow of water, what is in the pool will begin to evaporate - eventually leaving the rods dry and increasingly hot.

Whichever turns out to be the source, the International Atomic Energy Agency (IAEA) reports: "Dose rates of up to 400 millisievert per hour (mSv/hr) have been reported at the site."


Fuel rods in rapidly-drying pools may be the source of increased radiation levels Acccording to the World Health Organisation (WHO), the average person's exposure is 3mSv in a year.

A key question is whether this is just a transient spike or turns into a sustained release.

If a suppression chamber crack is the source, a spike is possible - and this is hinted at in local news reports, with the national agency Kyodo for example saying: "Radiation of up to nine times the normal level was also briefly detected" in Kanagawa prefecture, south of Tokyo.

Under normal circumstances, the suppression chamber stores a large volume of water that can be used to condense steam produced in the reactor.

The industry newsletter World Nuclear News reports that a "loud noise" came from the reactor chamber, and that "the pressure... was seen to decrease from three atmospheres to one atmosphere after the noise, suggesting possible damage".

This pressure drop is consistent with the chamber cracking and releasing steam.

If the chamber is now de-pressurised, it is likely that radioactive material will be ejected at a lower rate.

...

http://www.bbc.co.uk/news/science-environment-12745186?utm_source=twitterfeed&utm_medium=twitter

[Ronan Kelly]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

Attached document is radiation levels (I think at dai-ichi - Makoto could you confirm?)

Scroll down to 8:31 on March 15 - massive radiation burst peaking at 9:00 with a reading of 11,930 microSv per hour.

http://www.tepco.co.jp/cc/press/betu11_j/images/110315e.pdf

[sharon sanders]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

machine translation -

First order and the promotion of primary cooling
24 min 19.00 3 twitter tweet on May 15 (NHK leaves the site and click)

For nuclear power plant Fukushima Daiichi longer be ensured cooling enough, Minister of Economy 海江田, as well as to prevent reaching a critical re-fuel of Unit 4 had to stop driving to work cooling Unit 2 ordered in writing to proceed under the law early.

For Unit 4 of Fukushima Daiichi Nuclear Power Station, TEPCO has run out of water in the pool to store nuclear fuel rod is exposed, and possibly to a hydrogen explosion.

As for Unit 2 is low water level in the reactor, seen as continued state exposed the entire fuel rods over a half hours the night of 14 and then recover the water level up to about soaking more than half of the entire nuclear fuel I had to. In response, the Minister issued an order on the basis 海江田 Reactor Regulation Law.

For Unit 4 ▽ is, the higher the temperature is missing the pool water to store nuclear fuel, and prevent from reaching a critical cause a chain reaction is fission,

for Unit 2 ▽ is the water to cool the reactor injected as soon as possible, if necessary, remove the air inside the containment vessel is ordered to reduce the pressure.

http://www3.nhk.or.jp/news/html/20110315/t10014697901000.html

[sharon sanders]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

machine translation -

Holes in the outer wall in two places to No. 4 Fall
6:20 min 3 twitter tweet on May 15 (NHK leaves the site and click)

Nuclear and Industrial Safety Agency of the Ministry of Economy, 15 am to the sound of an explosion in the No. 4 of Fukushima Daiichi Nuclear Power Station, the results were examined, the outer wall of the building fell, two places open square hole 8 m found that for Teita.

According to the Nuclear and Industrial Safety Agency, 15 minutes 14:06 am, hear the sound of an explosion in the No. 4 Fukushima Daiichi Nuclear Power Station, where the employee went to the scene, the northwest side of the building containing the reactor is that a hole had to fall in two places in the outer wall. 8 square meters in both holes, but I suspect there was an explosion, the cause is that you know about. Also, at 9 am and 38 minutes and then about three hours after the fire broke out close to the fourth floor of the building at Unit 4, at around 11 am, it was confirmed that the naturally disappear. No. 4 was in for periodic inspections is not to drive while the reactor is empty, all the fuel was placed in a pool of water near the containment vessel for storage. Thus, the pool temperature is raised they become a fluid situation, 14 is that it had been about 40 degrees to 84 degrees higher than normal. Unit 4 pools of water, but also likely to fuel the heat of vaporization, in NISA, what's going on now is knowing the level of the future, how to inject water has to consider.

http://www3.nhk.or.jp/news/html/20110315/t10014698981000.html

[CopitoSP]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

UPDATE 1-French nuclear agency now rates Japan accident at 6


Tue Mar 15, 2011 8:28am EDT

(Reuters) - France's ASN nuclear safety authority said on Tuesday the nuclear accident at Tokyo Electric Power Co's Fukushima Daiichi plant could now be classed as level six out of an international scale of one to seven.

On Monday, the ASN had rated the ongoing accident at the plant, located 240 km (150 miles) north of Tokyo, as a five or six.

Level seven was used only once, for Chernobyl in Ukraine in 1986. The 1979 accident at the Three Mile Island nuclear power plant in the United States was rated a level five.

"We are now in a situation that is different from yesterday's. It is very clear that we are at a level six, which is an intermediate level between what happened at Three Mile Island and Chernobyl," ASN President Andre-Claude Lacoste told a news conference in Paris on Tuesday.

"We are clearly in a catastrophe," Lacoste added, citing the deterioration of the containment structure at Daiichi 2 as one of the key elements supporting the ASN's more pessimistic assessment.

Two reactors exploded on Tuesday at the Fukushima Daiichi plant after days of frantic efforts to cool them. [ID:nLDE72D2FT]

Japan, which rated the accident a four on Saturday, is under global scrutiny over its handling of a nuclear crisis triggered by a huge earthquake and tsunami that crippled three reactors and raised fears of an uncontrolled radiation leak.

http://www.reuters.com/article/2011/03/15/japan-quake-nuclear-france-idUSLDE72E1HX20110315

[sharon sanders]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

machine translation -

"The helicopter water injection into the pool" A Study
22:30 May 15, at 3 twitter tweet (click on the site leaves the NHK)

TEPCO night 15 press conference about the Fukushima Daiichi Nuclear Power Station Unit 4 stuck in the refrigerator to store nuclear fuel pool under the influence of the earthquake, after 15 days, sprinkle water from the air using a helicopter unveiled that the injection may be considered.

Specifically, the morning 15 days, the explosions in the building containing the reactor of Unit 4, because it has damaged the roof, to inject sprinkle the water by helicopter to work extinguishing forest fires from there is that supposed to be. However, at this time whether there is a suitable hole in the roof that is not confirmed that. Therefore, TEPCO was impossible if the way helicopter, 15 am, followed by explosions, a hole from the outer wall of eight square meters, can also consider using a fire truck to water is that. The Fukushima Daiichi nuclear power plant, in addition to this, but continued to work into the water to cool their reactors, but the situation has continued to rise the water level of cooling water, TEPCO about this "water We might have a total failure, can not deny the possibility that the water leak has put continued, "and stated.

http://www3.nhk.or.jp/news/html/20110315/t10014701631000.html

[Anne]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

Press Release No. 8 of March 15, 2011 11:00 AM
15/03/2011 11:00

http://www.asn.fr/

ASN provides an update on the situation of nuclear Fukushima Daiichi, Fukushima Daini, and Tokai Onagawa - Degradation of the likely reactor containment Fukushima Daiichi 2.
I - Fukushima Daiichi Nuclear Power Plant

March 11, 2011 at 2:46 p.m. (local time), an earthquake struck central Fukushima Daiichi causing its automatic shutdown.

The earthquake also caused:

* The loss of both offsite power plant that has not been compensated by standby generators for reasons currently unknown;
* A tsunami that affected the pumping station necessary for the nuclear reactor cooling (heat sink).

March 15, the evacuation of the zone of 20 km around the plant were almost completed and the Japanese authorities have asked the safekeeping of the population within a radius of 30km. The overview of this area is now prohibited.

Voluntary relief operations speaker lead to radioactive releases. Records of detection tags on the site show a high dose rate, with significant spikes in the vicinity of reactors 2 and 3, only about fifty workers remain on the site to ensure the necessary operations. The wind direction is now oriented towards the south-west towards the city of Tokyo, but should again move to the Pacific Ocean in the coming hours. Results from beacons located near the Tokyo metropolitan area are evaluated by IRSN; an increase in radioactivity is measured, but no significant health impact is noted at this time.
I.1 - Point of the situation on the No. 2 reactor

The reactor No. 2 now focuses the main concerns.

Partial melting of the heart is confirmed, the operator continues the operation of cooling the heart by injecting sea water whenever possible. The operator would have difficulty to perform these operations due to blockage of a relief valve of the tank.

Two successive explosions, at 06:10 am and 10 am (local time) probably led to a degradation of the containment led to significant increases in radioactive discharges detected.

To recall, the No. 2 reactor was automatically shut down during the earthquake. He had not been cooled for several hours.
I.2 - Summary of the situation on the reactor No. 4

A fire broke out on the reactor No. 4 at around 09:30 (local time) at the pool storage of spent fuel, the state spent fuel stored in this pool, potentially affected by fire is not determined.

The fire was extinguished around 12:00 (local time), the Japanese authorities, however, indicate that radioactive discharges are likely to be directly emitted to the atmosphere.

The reactor was shut down for maintenance during the earthquake.
I.3 - Taking stock of reactors No. 1 and 3

Partial melting of hearts of these two reactors is confirmed. Cooling the reactor by injecting seawater continues much as possible. The containment is maintained integrity after the explosions occurred on these reactors.

Voluntary relief operations of the chamber are carried out regularly, and may lead to radioactive releases.
I.4 - Point of the situation on the reactors # 5 and 6

No reactors 5-6 were shut down for maintenance during the earthquake.

The situation does not change on these reactors.
II - Fukushima Daini Nuclear Power

The four reactors were automatically shut down following the earthquake; external power supplies are available.

The operator has confirmed to 12:00 (local time) that the four reactors were arrested in a normal manner and cooling is controlled.

The Japanese authorities have decided to evacuate the public in a radius of 10 km. Tags measurement of radioactivity around the site have found no increase in radioactivity compared to the usual level.
III - Nuclear Power Onagawa

The three reactors, operated by Tohoku Electric Power, would be controlled by the Japanese authorities, and their situation has not changed in recent hours.

The first level of the state of emergency in the Central Onagawa has been declared following levels of radioactivity recorded. The Japanese authorities have confirmed that the detection of radioactive releases was due to emissions from the plant in Fukushima Daiichi; radioactivity levels returned to normal.
IV Nuclear Tokai

The Tokai plant has two reactors, the first of these reactors is stationary final since 1998.

Reactor No. 2:

The reactor is stopped.

Following the tsunami, one of the engines of 2 pumps of the reactor has stopped but the backup system is normally taken over.

The operator Japan Atomic Power Company control the situation, which has no particular trend.

[Anne]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

did some know if Mox is used in reactor 2 or 4 ( Mox is a mix with plutonium )

[sharon sanders]

Re: Japan - Fukushima Daiichi Nuclear Power Plant - Unit 1 Meltdown & Radiation released, Unit 3 had hydrogen explosion, Unit 2 problem cooling & possible fuel rod failure, and release of radioactive material

My understanding is that MOX is only in Unit 3. If anyone has different information, please post.

Thanks!