Japan verliest controle over kerncentrale(s)

[zonbron]

Oorspronkelijk geplaatst door maddox

En zal het niet worden ook niet. Het type reactor leent er zich niet toe.

Maar dat maakt geen zak uit als de gebruikte brandstof als corium in de kelders ligt af te koelen.

Kelders ? mmm Suppression Pool ?

[zonbron]

Bon. Goed nieuws. Alle 6 reactoren ONLINE.

All 6 Fukushima reactors reconnected to external power
TOKYO, March 22, Kyodo

All six reactors at the quake-stricken Fukushima Daiichi nuclear power plant have been reconnected to external power, plant operator Tokyo Electric Power Co. said Tuesday, although smoke detected at the No. 2 and No. 3 reactors the day before had temporarily hampered efforts to restore power and cool down spent nuclear fuel pools.

Tokyo Electric said that it has restored lighting in the control room for the No. 3 reactor, a move that is expected to allow for more intensive work to bring the nuclear crisis under control and to restore the reactors' key cooling functions.

Tokyo Electric Executive Vice President Sakae Muto said, ''I think the situation will head toward a better direction, but it is too early to say that things have stabilized sufficiently.''

The spokesman of the government's nuclear safety agency, Hidehiko Nishiyama, told a separate press conference in the afternoon that if electricity starts to work, the actual condition of the plant would become ''visible'' and authorities would be able to check whether the current measures are sufficient to contain the crisis.

He also gave reassurance that a critical full-scale ''meltdown'' -- in which fuel rods melt completely or reach criticality again -- is unlikely.

While the prospects for an end to the crisis remain uncertain, executives of the utility known as TEPCO apologized in person for the first time since the March 11 quake crippled the nuclear plant to people who had been living near the plant and have now been evacuated.

Although white smoke, possibly steam, was found to be billowing from the buildings of the No. 2 and No. 3 reactors from Monday, TEPCO resumed the work to restore electricity in the morning as it found radiation levels had not surged markedly at the site.

Regaining power supply is needed for the restoration of equipment such as a ventilation system to filter radioactive substances from the air and some measuring tools in the control room, as well as to eventually restore the reactors' key cooling functions that were lost in the quake and ensuing tsunami.

At present, workers cannot remain in the room for long hours due to high radiation levels and power outages.

The number of reactors to which external power has been connected increased from Sunday, with the last being the No. 3 reactor, but workers need to check the condition of each piece of equipment before transmitting power, according to the Nuclear and Industrial Safety Agency.

Efforts to cool down spent fuel pools, which could create the risk of radioactive substances being released if water is not replenished, also resumed in the afternoon and firefighters sprayed a massive amount of water onto the spent nuclear fuel pool at the No. 3 reactor.

Lees meer, Kyodo

[zonbron]

Volledige stand van zaken.

Status of Fukushima nuclear power plants Tuesday night
TOKYO, March 23, Kyodo

The following is the known status as of Tuesday night of each of the six reactors at the Fukushima Daiichi nuclear power plant and the four reactors at the Fukushima Daini plant, both in Fukushima Prefecture, which were crippled by the magnitude 9.0 earthquake and ensuing tsunami on March 11.

Fukushima Daiichi plant

-- Reactor No. 1 (Operation suspended after quake)

Partial melting of core, cooling failure, vapor vented, building housing containment of reactor damaged by hydrogen explosion, roof blown off, seawater being pumped in, work to restore electric power in progress.

-- Reactor No. 2 (Operation suspended after quake)

Damage to reactor containment structure feared, cooling failure, seawater being pumped in, fuel rods fully exposed temporarily, vapor vented, building housing containment of reactor damaged by blast at adjacent reactor No. 3, blast heard near suppression chamber of containment vessel, access to external power restored Sunday, steam seen rising Monday, pool holding spent-fuel rods filled with water on Tuesday with water temperature at 51 C.

-- Reactor No. 3 (Operation suspended after quake)

Partial melting of core feared, cooling failure, vapor vented, seawater being pumped in, building housing containment of reactor badly damaged by hydrogen explosion, seawater dumped over spent-fuel storage pool by helicopter Thursday, water sprayed at it from the ground for six days through Tuesday, workers temporarily forced to evacuate due to grayish smoke seen billowing from roof on Monday, lighting back on in control room on Tuesday.

-- Reactor No. 4 (Under maintenance when quake struck)

No fuel rods in reactor core, renewed nuclear chain reaction feared at spent-fuel storage pool, fire at building housing containment of reactor, only frame remains of reactor building roof, temperature in the pool reached 84 C on March 14, water sprayed at pool for three days through Tuesday.

-- Reactor No. 5 (Under maintenance when quake struck)

Some fuel rods left in reactor core, cooling in spent-fuel storage pool resumed Saturday, cold shutdown at reactor on Sunday, access to external power restored, power source switched to external power from emergency power on Monday.

-- Reactor No. 6 (Under maintenance when quake struck)

Some fuel rods left in reactor core, emergency power generator and cooling functions restored Saturday, cold shutdown at reactor on Sunday.

Fukushima Daini plant

-- Reactors No. 1, 2, 3, 4 (Operation suspended after quake)

Cold shutdown, not under emergency status.

==Kyodo

[zonbron]

Thermale beelden Fukushima



www.welt.de

[Bob]

Oorspronkelijk geplaatst door zonbron

Afbeeldingen in deze pdf file, NPRE 457 CSE 462 Safety Analysis of Nuclear Reactor Systems/Containment Structures.pdf bevestigen dat de figuren die ik gepost heb de reele structuur voldoende benaderen.

https://netfiles.uiuc.edu/mragheb/ww...Structures.pdf

Interessante nota. Maar ze spreken toch nergens over uitgedampte "spent fuel pools", doch enkel over "spent fuel pools waar de temperatuur het kookpunt benaderd". Langs den andere kant is het mijn gevoel wel mogelijk dat bepaalde staven in de "spent fuel pools" beschadigd zijn (door een ontploffing, door vallende brokstukken, of gewoon door hoge temperatuur).
Maar kom, ik kan mij vergissen. We zullen het allemaal nog wel te weten komen.

[zonbron]

22 Maart 2011 Japan NHK TV




Geen Burning Debris rond de centrales te bespeuren. Merk op, het dak van nr.2 lijkt ook wat warm te zijn.

[Asshen Sukar]

Oorspronkelijk geplaatst door Bob

Interessante nota. Maar ze spreken toch nergens over uitgedampte "spent fuel pools", doch enkel over "spent fuel pools waar de temperatuur het kookpunt benaderd". Langs den andere kant is het mijn gevoel wel mogelijk dat bepaalde staven in de "spent fuel pools" beschadigd zijn (door een ontploffing, door vallende brokstukken, of gewoon door hoge temperatuur).
Maar kom, ik kan mij vergissen. We zullen het allemaal nog wel te weten komen.

De analyse ervan stond in NYT. Het is een reactor die gebouwd is om heel zuinig met uranium om te gaan.
Fout erin is dat de spent fuel op een platform geplaatst is en niet de grond.
Gezien de fuel niet uit het water mag komen moet het hoog geplaatst worden.

Hoger boven de grond heeft een aardbeving meer effect dan in de grond.

Geen idee of de analyse van vandaag of gisteren is op de NYT.

[zonbron]

China stuurt hulp.

Chinese heavy machinery on way to Japan

China has been offering assistance, including relief materials and personnel to Japan since the magnitude-9 earthquake and tsunami hit the country and damaged the nuclear power plant in Fukushima Prefecture. And now, a water pump with an arm of 62 meters is on its way to join the rescue operation.
The water pump has arrived in Shanghai from Hunan Province. On Tuesday, it will be sent by sea to Osaka, Japan. It is expected to be put into use on Wednesday.
The especially long arm enables the machine to pump water to 62 meters high, equivalent to the 23rd floor in a high-rise.
Ever since the nuclear crisis broke out in Fukushima, the Japanese authorities have tried a variety of methods, including helicopters and fire-trucks, to spray water and cool down the nuclear reactors. But no desirable effects have been achieved.
While water pumps have become the latest prescription for the pressing problem, the arms of the Japanese-made ones are just not long enough. So Japan asked the Sany Group for help. It's one of three manufacturers that can produce the longest arms in the world.
The Sany Group decided to donate the machine to Japan. The company also dispatched two senior engineers and three technical consultants to provide training.
He Zhenlin, Vice Chairman of Sany Group said "We have prepared enough fittings and our best engineers are also going to Japan. I hope our effort can help meet their pressing need to cool down the reactor."
The machine is also able to pour cement and concrete on high-rise buildings. It's going to be the major force if radioactive materials need to be buried.

http://english.cntv.cn/program/china...1/108058.shtml

[zonbron]

Amerikaanse militairen en hun families poetsen de plaat.

U.S. military considers mandatory evacuations in Yokosuka, Japan

Washington (CNN) -- The U.S. military is considering the mandatory evacuation of thousands of American troops and their families in Japan out of concern over rising radiation levels, a senior defense official tells CNN.
The official, who did not want to be on the record talking about ongoing deliberations, says there are no discussions to evacuate all U.S. troops across the country. The talks have focused exclusively on U.S. troops in Yokosuka, just south of Tokyo, the official said. Yokosuka is home to America's largest naval base in Japan. The military is monitoring radiation levels on a constant basis.
As of Monday, the U.S. Navy had no more warships in port at the base. The aircraft carrier USS George Washington, which had been undergoing maintenance in Yokosuka, left port Monday to get away from the plume of radioactive particles that could blow over the base. Because it left port with a much smaller than normal crew, the George Washington will not take part in the Japanese relief effort.
The official said the talks originated with Pacific Command, the military authority that directly oversees U.S. troops in the region, but "discussions have since taken place here in Washington as well."
The official told CNN this is strictly a contingency plan, and could be accomplished "if they needed to do it in a hurry, with gray tails," or large military transport planes like a C-17.

Meer : CNN

[Piero]

De toestand bij de kerncentrale van Fukishima schijnt kritiek te worden. Uit reactor 3 komt zwarte rook en de werkzaamheden zijn gestaakt. Alle acties om de reactoren en baden te koelen hebben tot dusver niet kunnen voorkomen dat de situatie instabiel is en dat de temperaturen telkens weer oplopen. De grote hitte en voortdurende aardschokken ter plaatse doen de zaak technisch gezien geen goed. Steeds vaker moet het personeel wegens stralingsgevaar worden teruggetrokken. Het moment waarop er zand stenen en cement op gestort moet worden is misschien nabij. En dan is ook dat weer een activiteit waarbij piloten aan levensgevaarlijke straling bloot staan.

Uit een van de reactoren van de Fukushima Dai’ichi reactor stijgt zwarte rook op. Beheerder Tepco heeft al zijn werknemers geëvacueerd uit de directe omgeving van de kerncentrale, zo meldt persbureau AP. Wat de rook veroorzaakt, is onbekend. Vlammen zijn niet gesignaleerd.

De koelingswerkzaamheden bij de Dai’ichi-centrale blijven met tegenslagen kampen. De stralingsniveaus in reactor 2 maakten het eerder vandaag onmogelijk om verder te gaan met werkzaamheden daar. Ook waren enkele naschokken te voelen in de buurt van de zwaar beschadigde kerncentrale. De zwaarste had een kracht van 6.0 op de schaal van Richter. Of hierdoor extra schade is aangebracht aan de reactoren, is onbekend.

[zonbron]

Idd Piero, de strijd gaat onverminderd door.

Restoration at nuke plant disrupted, radiation fears spread to Tokyo
TOKYO, March 23, Kyodo

Work to restore power and key cooling functions was disrupted again Wednesday at the crisis-hit Fukushima Daiichi nuclear plant as smoke caused workers to evacuate, while fear of radioactive pollution spread to Tokyo with an alert not to give tap water to infants.

Chief Cabinet Secretary Yukio Edano urged residents of areas under the wind from the plant to stay indoors and avoid exposure to air as much as possible as a precaution, while official advisories are for people within a 20-kilometer radius to evacuate and within 20 km to 30 km to stay indoors.

The plant operator Tokyo Electric Power Co. said it learned at around 4:20 p.m. that black smoke was seen rising at the No. 3 reactor building, leading to evacuation of workers from the four troubled reactors, but added about an hour later that it was receding.

The radiation level was unchanged shortly afterward, meaning the smoke caused no massive release of radioactive materials, the government's nuclear safety agency said. Smoke was also seen billowing from the No. 3 building on Monday.

It also turned out that the surface temperatures of the No. 1 and No. 3 reactor vessels have topped the maximum levels set by their designers. The rise of the temperatures came to light after data measuring instruments became available with the power restored Tuesday, the agency said.

In Tokyo, the metropolitan government said radioactive iodine exceeding the limit for infants' intake was detected in water at a purification plant, apparently due to the ongoing crisis at the power station crippled by the March 11 massive quake and tsunami.

At the plant run by the utility known as TEPCO, all six reactors were reconnected to external power as of Tuesday night and workers scrambled to check each piece of equipment, such as data measuring tools and feed-water pumps, before transmitting power to them.

As part of efforts to restore lost functions at the plant, TEPCO aimed to first revive a pump by Thursday to inject fresh water into the core of the No. 3 reactor, instead of seawater that has currently been poured using fire pumps, the Nuclear and Industrial Safety Agency said.

While the maximum vessel temperature set by the reactors' designers is 302 C degrees, the surface temperature of the No. 1 reactor vessel briefly topped 400 C and dropped to about 350 C by noon, and that of the No. 3 reactor vessel stood at about 305 C, the agency said.

Although the facilities are not expected to start melting at those temperatures, according to agency spokesman Hidehiko Nishiyama, TEPCO increased the amount of seawater injected into the No. 1 reactor by nine times to help cool it down.

Nishiyama said TEPCO will carefully continue to inject massive amounts of water into the No. 1 reactor so as not to raise the pressure in the reactor.

Massive water injection could raise pressure in the reactor, which increases the risk of damage to the facility, and workers would be required to release radioactive steam from the reactor to lower the pressure.

At the No. 2 reactor, workers have been unable to replace a pump to help revive its internal cooling system since Friday as high-level radiation amounting to at least 500 millisieverts per hour was detected at its turbine building, the spokesman said.

Water-spraying operations, meanwhile, continued in the morning at the No. 4 reactor unit to help cool down its spent nuclear fuel pool, using trucks with a concrete squeeze pump and a 50-meter arm capable of pouring water from a higher point.

But similar operations for the No. 3 reactor were put off due to the smoke.

Also on Wednesday, a series of strong aftershocks jolted the coastal area of Fukushima Prefecture where the crippled plant is located, but they did not affect the restoration work, the nuclear agency said.

TEPCO said two workers who had been installing a makeshift power source from Tuesday night were injured and taken to hospital, but they were not exposed to radiation.

Lighting in a control room for the No. 3 and No. 4 reactors was partially restored Tuesday night, a key step toward regaining control of the situation as operators have been unable to remain in any control rooms for long hours due to high radiation levels and power outages.

Kyodo

[zonbron]

De eerste resultaten van de simulaties van SPEEDI dat terug in werking is.

Infant radiation dose over 30 km from plant may be over 100 millisieverts
TOKYO, March 24, Kyodo

The radiation dose received by one-year-old infants outside of a 30-kilometer radius of the Fukushima Daiichi nuclear plant since Saturday's explosion at the plant may have exceeded 100 millisieverts, a computer simulation conducted by the government showed Wednesday.

''There are some cases in which they could have received more than 100 millisieverts of radiation, even if they're outside the 30-kilometer radius and in the event that they spent every day outdoors since the explosion at the Fukushima nuclear plant,'' Chief Cabinet Secretary Yukio Edano told a news conference.

Haruki Madarame, chairman of the Nuclear Safety Commission of Japan, told reporters, ''The figure represents the level that one-year-old infants would have received and accumulated in their thyroids by midnight Wednesday since the explosion.''

Madarame said the radiation dose accumulated by adults outside the 30-km zone in their thyroids would be lower.

People exposed to a radiation dose of 100 millisieverts are required to take potassium iodide, Madarame said. An annual radiation dose of 100 millisieverts is believed to be associated with an increased risk of cancer.

But Edano said, ''Our analysis shows that people outside the 30-km radius would not be in a situation where they would have to evacuate immediately or remain indoors.''

''As a precautionary measure, I would like to recommend that if people (outside the 30-km radius) are on the leeward of the nuclear power plant, they close their windows and stay indoors inside sealed buildings as far as possible,'' he said.

The simulation was conducted using the Nuclear Safety Technology Center's networked computer system, called the System for Prediction of Environmental Emergency Dose Information, known as SPEEDI.

The system enables the center to predict the spread of radioactive substances and their amounts over 48 hours by analyzing the direction of winds and landscape.

...

Kyodo

[Bob]

De temperaturen van 400°C hebben betrekking op het reaktordeksel, wat dan weer niet zo onwaarschijnlijk is (maar wat mi wel wil zeggen dat er niet veel water meer in de reaktor zit). Vraag mij wel af hoe ze dit meten, op het moment (of zijn de metingen hiervan terug beschikbaar ?).

[CyberpunX]

Dit is ook wel redelijk verontrustend imo. Is dit een teken dat een meltdown bezig is?

Neutron beam observed 13 times at crippled Fukushima nuke plant
http://english.kyodonews.jp/news/2011/03/80539.html

En Europa zit er nu ook mee opgezadeld.

http://www.redorbit.com/news/science...aches_iceland/

[maddox]

We kunnen er van uit gaan dat de 3 zwaar getroffen reactoren een gedeeltelijke of gehele meltdown kennen.
Maar de bassins met gebruikte brandstof, dat zijn de echte zorgenkindjes.

[Asshen Sukar]

Oorspronkelijk geplaatst door CyberpunX

Dit is ook wel redelijk verontrustend imo. Is dit een teken dat een meltdown bezig is?


En Europa zit er nu ook mee opgezadeld.

Dit gaat om waardeloos lage cijfers. En zolang het Jodium, maakt het niks uit. Jodium halveert binnen 8 dagen.

[zonbron]

Oorspronkelijk geplaatst door Bob

De temperaturen van 400°C hebben betrekking op het reaktordeksel, wat dan weer niet zo onwaarschijnlijk is (maar wat mi wel wil zeggen dat er niet veel water meer in de reaktor zit). Vraag mij wel af hoe ze dit meten, op het moment (of zijn de metingen hiervan terug beschikbaar ?).

Ik denk niet dat die reeds beschikbaar zijn. Het is waarschijnlijk vanuit de lucht gemeten. Zie 1 van mijn vorige posts ivm het dagelijks inzetten van een helicopter om temperaturen te meten. Ik veronderstel natuurlijk dat dit enkel werkt (een betrouwbare meting) voor de centrales waar het 'dak' er af is.

[D'ARTOIS]

Vroeger werden eenheden in Rad' s aangegeven. Welke idioot komt er iedere keer weer met andere meet eenheden. Is dat dezelfde gek die van ato bar maakte?

[zonbron]

Het werk... hervat...

Restoration work resumed at Fukushima power plant
TOKYO, March 24, Kyodo

Tokyo Electric Power Co. on Thursday morning resumed work to restore power and key cooling functions at the Fukushima Daiichi nuclear plant after it was hindered the previous day when black smoke was observed at its No. 3 reactor building.

The utility company, known as TEPCO, said it has ensured it is safe for workers to return after evacuating due to the smoke at the plant, which has been crippled since the March 11 devastating earthquake and tsunami and has leaked radiation.

While the cause of the black smoke remains unknown, no fire was seen and the radiation level did not climb. The Nuclear and Industrial Safety Agency confirmed the smoke stopped as of 4:50 a.m. Thursday.

All six reactors at the plant had been reconnected to external power as of Tuesday night and workers scrambled to check each piece of equipment, including data measuring tools and feed-water pumps before transmitting power to them.

The science ministry, meanwhile, has launched monitoring of the radiation levels in soil, seawater and air around the plant to examine the extent of contamination and how it will affect the farm and fishery industries.

The Ministry of Education, Culture, Sports, Science and Technology, which has been monitoring the radiation level in areas 20 to 60 kilometers from the evacuation zone around the plant, said it also started collecting soil within that radius to check the amounts of radioactive iodine and cesium.

It will also monitor if the soil contains strontium, which can cause bone cancer and leukemia.

The ministry will also examine the radiation level in waters within around 30 km of the coast around the plant using a research vessel of the Japan Agency for Marine-Earth Science and Technology, while it will deploy helicopters of the Ground Self-Defense Force to check the area from the air.

==Kyodo

Kyodo



Geen nieuwe kerncentrales in Texas.

Japan nuclear crisis threatens reactor plan in Texas: WSJ
NEW YORK, March 23, Kyodo

NRG Energy Inc. may delay or even cancel its plan to build two reactors at the South Texas nuclear plant in cooperation with Toshiba Corp. and Tokyo Electric Power Co. due to Japan's nuclear crisis, The Wall Street Journal reported Wednesday.

Such a setback would represent the most tangible repercussion so far for the U.S. nuclear industry from the crippled Fukushima Daiichi nuclear plant in quake-hit Japan, the newspaper said.

Quoting NRG Chief Executive Officer David Crane, the daily said the reactor project could be derailed because of several hurdles such as garnering financial support from Tokyo Electric, the operator of the troubled nuclear plant.

Kyodo


Ook andere zones/landen hebben hetzelfde beslist.

Meer info betreffende de intenties van verschillende landen later.

[zonbron]

De problemen met Fukushima centrale hebben de reddingswerken bemoeilijkt

Nuke disaster hinders searches for missing in Fukushima
TOKYO, March 24, Kyodo

The search for missing people following the March 11 devastating earthquake and tsunami has been hindered in Fukushima Prefecture by the nuclear disaster there, rescue workers said Thursday.

Self-Defense Forces personnel said it was possible bodies had been left behind, as they faced difficulty entering areas under evacuation orders due to the crisis at the Fukushima Daiichi nuclear plant. Fukushima Prefecture accounts for around 8 percent of the national death toll.

People living in a 20-kilometer radius of the plant have been under directives to evacuate and those within 20 km to 30 km have been advised to stay indoors. SDF rescue workers deployed in Fukushima have thus focused on supporting evacuation of residents, including bed-ridden hospital patients, rather than searching for the missing, they said.

According to the National Police Agency, more than 25,000 people were confirmed dead or remained unaccounted for following the quake as of 9 a.m. -- 9,523 dead and 16,067 missing.

...

Kyodo