Löpande uppdateringar om den japanska jordbävningen och kärnkraftverken

Last updated on March 1, 2013

Uppdatering 11:59

Lite experter spekulerar på Reuters

http://www.reuters.com/article/2011/03/12/us-japan-quake-experts-idUSTRE72B1BP20110312

ROBIN GRIMES, PROFESSOR OF MATERIALS PHYSICS AT IMPERIAL COLLEGE LONDON

“It does seem as if the back-up generators although they started initially to work, then failed,” Grimes, an expert in radiation damage told BBC TV.

“So it means slowly the heat and the pressure built up in this reactor. One of the things that might just have happened is a large release of that pressure. If it’s that then we’re not in such bad circumstances.

“Despite the damage to the outer structure, as long as that steel inner vessel remains intact, then the vast majority of the radiation will be contained.

“At the moment it does seem that they are still contained and it’s a release of significant steam pressure that’s caused this explosion. The key will be the monitoring of those radiation levels.”

PROFESSOR PADDY REGAN, NUCLEAR PHYSICIST FROM BRITAIN’S SURREY UNIVERSITY

“What is important is where that explosion is,” Regan told Sky News.

“It’s not clear what has exploded. The big problem would be if the pressure vessel has exploded but that does not look as though that’s what’s happened.

“If the pressure vessel, which is the thing that actually holds all the nuclear fuel … if that was to explode — that’s basically what happened at Chernobyl — you get an enormous release of radioactive material.

“It doesn’t look from the television pictures … as though it’s the vessel itself.

He said media reports suggested that a small fraction of the nuclear fuel might have melted at the core of the reactor which would not be surprising.

NUCLEAR EXPERT MARK HIBBS OF THE CARNEGIE ENDOWMENT FOR INTERNATIONAL PEACE

“We don’t have any information from inside the plant. That is the problem in this case.

“If it melts down the probability that there would be a breach or that radiation would get outside of the plant because of weakness of the structure of the plant … is much greater.”

Uppdatering 11:06

Video av explosionen, det är svårt att se vad som exploderat

http://www.bbc.co.uk/news/world-asia-pacific-12721498

Uppdatering 10:58

http://www.svd.se/nyheter/utrikes/risk-for-hardsmalta-i-japan_6001247.svd

TOKYO (Dow Jones)–An explosion was heard and white smoke was seen around the Fukushima Daiichi nuclear power plant late Saturday afternoon in Japan, though the cause and exact location of the event were not immediately clear, according to Japan’s national broadcaster NHK.   Several people appeared to have been injured in the incident, NHK said.

Reuters – Japan Chief Cabinet Secretary Edano: expands evacuation area at no.2 plant to 10 km.

Bloomberg Reactor Fuel Rods May Have Started to Melt 2011 03 12 | 0345 EST

A nuclear reactor in the Fukushima Dai-Ichi power station about 220 kilometers (140 miles) north of Tokyo may be starting to melt down after Japan’s biggest earthquake on record hit the area yesterday.

Fuel rods at the No. 1 reactor at the plant run by Tokyo Electric Power Co. may be melting after radioactive Cesium material left by atomic fission was detected near the site, Nuclear and Industrial Safety Agency, spokesman Yuji Kakizaki said by phone today.

“If the fuel rods are melting and this continues, a reactor meltdown is possible,” Kakizaki said. A meltdown refers to a heat buildup in the core of such an intensity it melts the floor of the reactor containment housing.

Wall Street Journal – Japan Scrambles to Avert Meltdown – |2011 03 12 | 0252 EST

TOKYO—Emergency measures taken to avert a meltdown at a nuclear power plant hit by Friday’s massive earthquake in northern Japan appear to be working, the plant’s operator said after earlier warning that it faced a meltdown threat.

Workers are bringing down dangerous pressures that had built up in the container for the Fukushima Daiichi No. 1 nuclear reactor, a spokesman for Tokyo Electric Power Co. said Saturday afternoon.

“The steps we have taken through relieving the pressure inside the container and adding additional water to cool the rods appear to be succeeding in averting any damage to the reactor core, which was our main priority,” said a Tepco spokesman.

Previously, the utility had said there was a risk of a meltdown in the core after the quake cut off power to pumps providing cooling water. That, in turn, could lead to heating of the core, the risk of a meltdown, and the release of radiation.

A portion of the reactor’s fuel rods, which create heat through a nuclear reaction, had become exposed due to the cooling-system failure. The spokesman for Tepco said 1.5 meters of the 4.5 meter long fuel rods were exposed. It was unclear Saturday afternoon whether the water added by workers had re-covered the rods.

Loss of cooling water resulted in a near meltdown of the Three Mile Island reactor in Pennsylvania in 1979, the worst nuclear incident in U.S. history.

Asked about the impact of radiation at eight times higher than normal levels, Naoto Sekimura, a professor of quantum engineering at Tokyo University, said on national broadcaster NHK, “This is a minuscule amount. This is not going to have negative impact on the human body.”

Later on Saturday, Tokyo Electric said another nuclear-power plant nearby, Fukushima Daini, was experiencing rises of pressure inside its four reactors. A state of emergency was called and precautionary evacuations ordered. The government has ordered the utility to release “potentially radioactive vapor” from the reactors, but hasn’t confirmed any elevated radiation around the plant.

Uppdatering 00:14

http://english.kyodonews.jp/news/2011/03/76965.html

Japan’s nuclear safety agency is set to issue an unprecedented order for Tokyo Electric Power Co. to open a valve at the troubled Fukushima No. 1 nuclear power plant to release pressure following a powerful earthquake, it said Saturday.

Kommentar
Nu verkar det som man kommer köra med ventileringen av inneslutningsbyggnaden som det har pratats om. Vad som kommer ske då  är att man öppnar någon slags nödventil som är kopplade till diverse filtersystem gjorda för att snappa upp flyktiga radionuklider som jod odyl. Det har inte rapporterats om att vattennivån i härden ska ha sjunkit under nivån för bränslestavarna under någon del av processen hittills, därmed så borde bränslet vara i stort sett intakt. Om det stämmer så kan det inte finnas särskilt mycket radionuklider i inneslutningen och ventileringen lär ha ringa, om någon, påverkan på omgivningen. 

Uppdatering 00:05

Reuters
http://live.reuters.com/Event/Japan_earthquake2

Power company TEPCO says it has lost the ability to control reactor pressure at Fukushima No. 1 and No.2 reactors. A spokesman said pressure is stable inside the reactors but is rising in the containment vessels. He said it is not known if there will be a need to release pressure at the plant at this point. That would involve a release of radiation.

Uppdatering 23:08

För att ge lite snabbt perspektiv på siffran 1000ggr normal nivå. Normal nivå om det vore Sverige är 3-5 mSv(milli sievert) per år. Om vi antar att samma gäller i Japan så blir det alltså 8-14 mSv per dag. Gränsen för vad en kärnkraftsarbetare får lagligt sett utsättas för är 20 mSv per år. Så 8-12 mSv är en relativt hög siffra, men långt ifrån omedelbart skadligt. För omedelbara effekter måste man komma upp i ungefär 1000 mSv(100 dagar med den strålningsnivå som nu råder).

Uppdatering 22:52

http://www.dn.se/nyheter/varlden/nytt-forsok-kyla-reaktorn

http://english.kyodonews.jp/news/2011/03/76948.html

The amount of radiation reached around 1,000 times the normal level Saturday in the control room of the No. 1 reactor of the Fukushima No. 1 nuclear power plant, the Nuclear and Industrial Safety Agency said.

The discovery suggests radioactive steam could spread around the facility operated by Tokyo Electric Power Co.

Kommentar

Jag har inte lyckats hitta någon information om detta är pga avsiktlig ventilering av inneslutningen.

Uppdatering 22:45

http://www.cnn.com/2011/WORLD/asiapcf/03/11/japan.nuclear/index.html?hpt=T1
Early Saturday morning, Prime Minister Naoto Kan said that the evacuation order had been extended to those within 10 kilometers of the plant.

Uppdatering 22:20

DN verkar ha bestämt sig för att faktiskt skriva ut lite mer av vad Gunsell måste ha sagt, istället för att försöka enbart skrämmas.

http://www.dn.se/nyheter/varlden/nytt-forsok-kyla-reaktorn

Om inte kylsystemet kommer i gång är risken uppenbar för en härdsmälta, sade tidigare på fredagen Lars Gunsell, utredare vid Strålsäkerhetsmyndigheten (SSM) i Stockholm.

– Systemet i kärnkraftverket är avstängt men en reaktorhärd fortsätter att alstra värme lång tid efteråt. Och kyls den inte av smälter den.

Han påpekar samtidigt att en härdsmälta i anläggningen troligen inte skulle innebära några stora faror för omgivningen.

– Reaktorn ligger inne i kraftig betongbyggnad. Så även om härden smälter kommer inte särskilt mycket att komma ut i kringliggande områden. Ett mindre utsläpp kan det bli frågan om, men inget stort.

Uppdatering 22:02

http://www.tepco.co.jp/en/press/corp-com/release/11031207-e.html

Today at approximately 2:46PM, turbines and reactors of Tokyo Electric Power
Company's Fukushima Daiichi Nuclear Power Station Unit 1 (Boiling Water
Reactor, rated output 460 Megawatts) and Units 2 and 3 (Boiling Water
Reactor, Rated Output 784 Megawatts) that had been operating at rated
power automatically shutdown due to the Tohoku-Chihou-Taiheiyou-Oki Earthquake.
(already announced)

At this moment, we have decided to implement measures to reduce the pressure
of the reactor containment vessel for those units that cannot confirm certain
level of water injection by the Reactor Core Isolation Cooling System, in
order to fully secure safety.

We will endeavor to restore the units and continue monitoring the environment
of the site periphery.

Uppdatering 20:40

Statusuppdatering från TEPCO om deras reaktorer http://www.tepco.co.jp/en/press/corp-com/release/11031203-e.html

Unit 1 (shut down due to earthquake)
- Reactor was shut down and nuclear steam is cooled by the isolation condenser.
- Currently, there is a possibility of a release of radioactive materials
  due to decrease in reactor water level.  Therefore, the national government
  has instructed evacuation for those local residents within 3km radius of
  the periphery and indoor standby for those local residents between 3km and
  10km radius of the periphery.

Unit 2 (shut down due to earthquake)
- Reactor was shut down and although nuclear steam had been cooled by the
  Reactor Core Isolation Cooling system, the current operating status is
  unclear.  However, reactor coolant level can be monitored by a temporary
  power supply and the level is stable.
- Currently, there is a possibility of a release of radioactive materials
  due to decrease in reactor water level.  Therefore, the national government
  has instructed evacuation for those local residents within 3km radius of
  the periphery and indoor standby for those local residents between 3km and
  10km radius of the periphery.

Unit 3 (shut down due to earthquake)
- Reactor was shut down and is cooled by the Reactor Core Isolation Cooling
  system.
- Currently, we do not believe there is any reactor coolant leakage inside
  the reactor containment vessel.

Unit 4 (shut down due to earthquake)
- Reactor has been shut down and sufficient level of reactor coolant to
  ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage inside
  the reactor containment vessel.

Unit 5 (outage due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant to
  ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage inside
  the reactor containment vessel.

Unit 6 (outage due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant to
  ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage inside
  the reactor containment vessel.

We measured radioactive materials inside and outside of the periphery of
the nuclear power station (outdoor area) by monitoring car and confirmed
that there was no difference from ordinary level.

No radiation impact to the external environment has been confirmed.
We will continue to monitor in detail the possibility of radioactive material
being discharged from exhaust stack or discharge canal.

Two subcontract workers were injured in the nuclear power station premise.
One with a broken bone was transported to the hospital by an ambulance and
the other by a company car.
Further, there are 2 TEPCO employees whose presence has not been confirmed.

We are presently checking on the site situation of each plant while keeping
the situation of aftershock and Tsunami in mind.

Uppdatering 20:23

http://www.world-nuclear-news.org/RS_Massive_earthquake_hits_Japan_1103111.html

Almost nine hours later, an announcement from the Ministry of Economy, Trade and Industry said that three of four mobile power supplies had arrived at Fukushima Daiichi and cables were being set up to supply emergency power. Other power modules were in transit by air.

However, pressure inside the containment of Unit 1 at Fukushima Daichi had been steadily increasing over the time that emergency core cooling systems have not been active. Tepco reported at 2am that pressure had increased beyond reference levels but was within engineered limits.

The company then announced a decision to reduce the pressure within containment “for those units that cannot confirm certain level of water injection” by the safety systems. “We will endeavor to restore the units and continue monitoring the environment of the site periphery.”

http://ansnuclearcafe.org/2011/03/11/media-updates-on-nuclear-power-stations-in-japan/

Another official at the nuclear safety agency, Yuji Kakizaki, said that plant workers were cooling the reactor with a secondary cooling system, which is not as effective as the regular cooling method.

Kakizaki said officials have confirmed that the emergency cooling system — the last-ditch cooling measure to prevent the reactor from the meltdown — is intact and could kick in if needed.

“That’s as a last resort, and we have not reached that stage yet,” Kakizaki added.

Kommentar

Om trycket i inneslutningen stiger för mycket så finns det sprängbleck som brister så att trycket kan sänkas, om det sker så leds den utblåsande luften genom långa filter(förmodar att reaktorn i fråga har liknande filter i inneslutningen som vi har i Sverige) för att eliminera alla radioaktiva gaser som kan finnas i inneslutningen ifall reaktorkärlet eller någon ledning läcker. Dock så kan lite radioaktiva ädelgaser slippa igenom filtren, men precis som man såg vid TMI olyckan i Harrisburg så är det inget större problem.

Uppdatering 18:06

De mobila dieselgeneratorerna har anlänt till Fukushima.

http://www.world-nuclear-news.org/RS_Massive_earthquake_hits_Japan_1103111.html

Almost nine hours later, an announcement from the Ministry of Economy, Trade and Industry said that three of four mobile power supplies had arrived at Fukushima Daiichi and cables were being set up to supply emergency power. Other power modules were in transit by air.

Uppdatering 17:39

DN påstår att SSM varnar för härdsmälta
http://www.dn.se/nyheter/varlden/2-000-evakueras-vid-karnkraftverk

Jag har svårt att tro att det är ett officiellt uttalande från SSM. Det måste vara en förvridning av vad Gunsell sagt. Det finns ingenting nu som tyder på att det ännu är någon risk för härdsmälta. Den första och mest kritiska timmen var härden kyld med dieselaggregaten och efteråt verkar det som att den batteridrivna nödkylningen har varit aktiv. Att då spekulera om härdsmälta är väldigt oförsiktigt. Att dessutom dra paralleller till Tjernobyl är helt obegripligt, även vid en total härdsmälta så bli det inte tal om något nytt Tjernobyl. Smältan hålls effektiv inne av inneslutningsbyggnaden. Det är enbart om härdsmälta dels lyckas smälta igenom reaktorkärlet och dels om inneslutningsbyggnaden är trasig som något slags utsläpp kan ske. Inte ens härdsmältan vid TMI i Harrisburg lyckades smälta sig igenom reaktorkärlet.

Vad som ligger bakom detta uttalandet från DN är fullständigt obegriplig och oansvarigt! Det är uppenbart att SSM’s ord måste ha förvrängts.

Uppdatering 17:31

http://www.reuters.com/article/2011/03/11/japan-quake-nuclear-pumping-idUSLDE72A1US20110311

(Reuters) – The World Nuclear Association, the main nuclear industry body, said on Friday that it understood the situation at Japan‘s Fukushima plant after a massive earthquake was under control, and water was being pumped into its cooling system.

“We understand this situation is under control,” an analyst at the association told Reuters.

The Japanese government had declared an emergency situation around the plant as a precaution and evacuated residents, saying a cooling system was not working.

The analyst said he understood that a back-up battery power system had been brought online after about an hour, and begun pumping water back into the cooling system, where the water level had been falling. (Reporting by Karolin Schaps; Writing by Kevin Liffey)

Uppdatering 16:44

REU: LONDON-WORLD NUCLEAR INDUSTRY ASSOCIATION SAYS IT UNDERSTANDS WATER BEING PUMPED BACK INTO COOLING SYSTEM AT FUKUSHIMA

Uppdatering 16:20

Läget börjar klarna lite. Dieselgeneratorerna för kylningssystemet fungerade i ungefär en timme. Sen dog dom av okänd anledning, men det är den första timmen som är mest kritisk. Restvärmeproduktionen från sönderfall av fissionsprodukter faller exponentiellt. Nu har det gått över 8 timmar och man har lyckats hålla härdarna kylda under hela den perioden. Sannolikheten att nått ska gå snett nu verkar väldigt liten. Portabla nödgeneratorer är på väg till kraftverket.

Uppdatering 16:17

http://twitter.com/#!/SkyNewsBreak

Jiji News: Fukushima nuclear reactor cooling system expected to be restored soon.

Uppdatering 15:38

http://www.jaif.or.jp/english/aij/member/2011/2011-03-11earthquake4.pdf

However, the reactor core still has a sufficient amount of water for cooling, with nodanger of the nuclear fuel being exposed. Several emergency generator vehicles haverushed to the scene to provide the necessary power for the water supply.At a press conference, Chief Cabinet Secretary Yukio Edano stressed that while therewas no confirmation of radiation leaking from the reactor, with sufficient time remainingfor its restoration, the government would direct residents living with a 3-km radius toevacuate, and other residents living outside that limit but within a 10-km radius wouldbe urged to stand by at home.

Uppdatering 15:32

http://www.world-nuclear-news.org/RS_Massive_earthquake_hits_Japan_1103111.html

Tokyo Electric Power Company (Tepco) has reported that emergency diesel generators started as expected at the Fukushima Daiichi nuclear power plant, but then stopped after one hour, leaving units 1, 2 and 3 with no power for important cooling functions. This led the company to notify the government of an ’emergency’ situation, which allows local authorities to take additional precautionary measures. An evacuation has been ordered of people living within three kilometres, while engineers work to restore power.

At neighbouring Fukushima Daini, sufficient cooling water is being maintained by injection using the reactor core isolation cooling systems of units 1 to 4. At unit 1 an increase in reactor containment pressure has been noted, and “assumed to be caused by leakage of reactor coolant in the reactor containment” this led Tepco to notify government of another emergency status.

Uppdatering 15:30

Från CNN
http://www.cnn.com/2011/WORLD/asiapcf/03/11/japan.nuclear/

(CNN) — Workers at a nuclear power plant in north-central Japan are having trouble cooling the reactor and authorities have asked nearby residents to evacuate, Chief Cabinet Secretary Yukio Edano said at a news conference Friday.

The Fukushima Nuclear Power Plant was shut down after the earthquake that hit the country.

“This is a precautionary instruction for people to evacuate. There is no radioactive leakage at this moment outside of the facility,” he said. “At this moment there is no danger posed to the environment.”

Japan declared a state of atomic power emergency after the earthquake, the Kyodo News agency reported. The government is sending senior officials and a defense force team to the power plant, it said.

Edano said plant workers were having trouble generating sufficient electricity to pump water into the cooling system. They were using all available backup electricity, he said.

“The emergency shutdown has been conducted but the process of cooling down the reaction is currently not going as planned,” he said.

Uppdatering 15:26

Den stora tragedin kan kanske vara explosionen i petrokemifabriken i Sendai. 70 000 personer evakuerade. Låt oss hoppas det inte blir till ett nytt Bhopal!

http://twitter.com/#!/mpoppel
Kyodo: 60,000-70,000 people evacuate to shelters in Sendai city: GSD

Uppdatering 15:23

Japan Atomic Industrial Forum uppdaterar om läget en gång i timmen

http://www.jaif.or.jp/english/index.php

Uppdatering 15:17

 

http://twitter.com/#!/mpoppel

Kyodo: Fukushima Pref. says enough water to cover fuel rods at nuke plant

Uppdatering 15:10

http://ansnuclearcafe.org/2011/03/11/media-updates-on-nuclear-power-stations-in-japan/

NucNet – 11 Reactors shut down in Japan 2011 03 11 0817 EST

TOKYO, March 11 (Xinhua) — Japanese Prime Minister Naoto Kan on Friday declared a state of atomic power emergency after an earthquake hit Japan’s northeastern Honshu island, but he denied there are any radiation leaks.

Chief Cabinet Secretary Yukio Edano said some cooling functions were not working at the plant and one reactor cannot be cooled down.

Separately, a fire broke out at a nuclear power plant in Miyagi Prefecture following the massive quake. Tokyo Electric Power Co. said that the fire started detected at a building housing the turbine at its Onagawa plant but denied any radiation leaks.

According to the ministry, 11 nuclear reactors were automatically shut down at the Onagawa plant, Fukushima No. 1 and No. 2 plants and Tokai No. 2 plant.

Uppdatering 14:58

 

American Nuclear Society kör en löpande uppdatering av situationen här.

http://ansnuclearcafe.org/2011/03/11/media-updates-on-nuclear-power-stations-in-japan/

Uppdatering 14:56

http://www.reuters.com/article/2011/03/11/japan-quake-reactor-idUSL3E7EB1K020110311

(Reuters) – A cooling system for a nuclear reactor was not working after a powerful earthquake in Japan, prompting the government to declare an emergency situation as a precaution although it said there was no radioactive leakage at present.

Residents that live within a 3 km radius of Tokyo Electric Power’s Fukushima Daiichi nuclear plant have been told to evacuate, Japan’s Chief Cabinet Secretary Yukio Edano told a news conference.

TEPCO confirmed that water levels inside the reactors at its Fukushima-Daiichi nuclear plant were on a falling trend, but added it was working to maintain water levels to avert the exposure of nuclear fuel rods.

The company has been trying to restore power to its emergency power system so that it can add water to the inside of the reactors, a TEPCO spokesman said. (Reporting by Osamu Tsukimori; Writing by Edwina Gibbs; Editing by Joseph Radford)

Uppdatering 14:50

Informationen är väldigt tunn ännu.  Enligt sky news så finns det alltså en fallande trend i vattennivåerna. Men det är allt som sägs. När en reaktor är snabbstoppad så återstår ungefär 1% av effekten pga sönderfall av fissionsprodukter. Det blir alltså en resteffekt på runt 30 MW som måste kylas bort. Om man antar ett värsta fall där man måste förse kretsen med nytt vatten så blir det alltså ungefär 13 liter per sekund som ska föras till kretsen för att ersätta det som kokas bort(för att koka 13 liter vatten krävs ungefär 30MJ eftersom heat of vaporization av en liter vatten är 2.26MJ). Om någon dieselgenerator är igång är det en enkel match. Men ingen information finns ännu om den nuvarande statusen för dieselgeneratorerna eller exakt vad som händer.

Uppdatering  14:48

IAEA http://www.iaea.org/newscenter/news/2011/tsunamiupdate.html

The IAEA’s Incident and Emergency Centre has received information from Japan’s Nuclear and Industrial Safety Agency (NISA) that a heightened state of alert has been declared at Fukushima Daiichi nuclear power plant. NISA says the plant has been shut down and no release of radiation has been detected.

Japanese authorities have also reported a fire at the Onagawa nuclear power plant, which has been extinguished. They say Onagawa, Fukushima-Daini and Tokai nuclear power plants were also shut down automatically, and no radiation release has been detected.

The IAEA received information from its International Seismic Safety Centre that a second earthquake of magnitude 6.5 has struck Japan near the coast of Honshu, near the Tokai plant.

The IAEA is seeking further details on the situation at Fukushima Daiichi and other nuclear power plants and research reactors, including information on off-site and on-site electrical power supplies, cooling systems and the condition of the reactor buildings. Nuclear fuel requires continued cooling even after a plant is shut down.

All IAEA staff in Japan, both in the Tokyo office and in nuclear facilities, are confirmed to be safe.

Uppdatering 14:39

Från skynews

Japanese News Agency: 200-300 bodies found along coast of northeastern Japan following earthquake and tsunami.

Japanese News Agency: Major explosion reported at petrochemical plant in Sendai.

Uppdatering 14:11,

från Sky news twitter feed
http://twitter.com/#!/SkyNewsBreak

Tokyo Electric Power Co confirms a “falling trend” in the water levels inside reactors at Fukushima nuclear plant.

****

Uppdatering
, JAIF har publicerat en lista på statusen för Japans alla reaktorer.

http://www.world-nuclear-news.org/RS_Massive_earthquake_hits_Japan_1103111.html

JAIF issued a statement giving the status of nuclear power reactors in the effected area of Japan. This was based on various information sources, including event reports from Nisa released half an hour after the earthquake struck.

Reactor	Operator	Status
Onagawa 1	Tohoku	Automatically shutdown
Onagawa 2	Tohoku	Automatically shutdown
Onagawa 3	Tohoku	Automatically shutdown
Higashidori 1	Tohoku	Shut for periodic inspection
Fukushima Daiichi 1	Tepco	Automatically shutdown
Fukushima Daiichi 2	Tepco	Automatically shutdown
Fukushima Daiichi 3	Tepco	Automatically shutdown
Fukushima Daiichi 4	Tepco	Shut for periodic inspection
Fukushima Daiichi 5	Tepco	Shut for periodic inspection
Fukushima Daiichi 6	Tepco	Shut for periodic inspection
Fukushima Daini 1	Tepco	Automatically shutdown
Fukushima Daini 2	Tepco	Automatically shutdown
Fukushima Daini 3	Tepco	Automatically shutdown
Fukushima Daini 4	Tepco	Automatically shutdown
Tokai	Japco	Automatically shutdown
Hamaoka 3	Chubu	Shut for periodic inspection
Hamaoka 4	Chubu	In normal operation
Hamaoka 5	Chubu	In normal operation
Kashiwazaki-Kariwa 1	Tepco	In normal operation
Kashiwazaki-Kariwa 2	Tepco	Not operating
Kashiwazaki-Kariwa 3	Tepco	Not operating
Kashiwazaki-Kariwa 4	Tepco	Not operating
Kashiwazaki-Kariwa 5	Tepco	In normal operation
Kashiwazaki-Kariwa 6	Tepco	In normal operation
Kashiwazaki-Kariwa 7	Tepco	In normal operation
Tomari 1	Hokkaido	In normal operation
Tomari 2	Hokkaido	In normal operation
Tomari 3	Hokkaido	In normal operation

In addition, the reprocessing plant at Rokkasho is being supplied by emergency diesel power generators.

****************

Ingen har nog missat att Japan idag har lidit av en enorm jordbävning och en efterföljande tsunami. Minst 44 personer har mist sina liv hittills i vad som redan är en stor tragedi.

Redan har frågor börjat dyka upp om hur de japanska kärnkraftverken påverkats. Man kan ha lite åsikter om varför ingen bryr sig om påverkan på kemiindustrin, petroliumindustrin odyl. Men den diskussionen kan sparas till ett senare tillfälle.

Vad vi vet just nu är helt enkelt bara det media rapporterar. I DN ser man den olycksbådande rubriken
Brand utbröt i kärnkraftverk

och SVD kör med en löpande rapportering om läget i Japan. Här är de kärnkraftsväsentliga uppdateringarna från SVD hittills. http://www.svd.se/nyheter/inrikes/svd-rapporterar-minut-for-minut_5998923.svd

********

13.28: 2 000 personer evakueras från området kring ett kärnkraftverk i i Fukushima i Japan som fått problem med kylningssystemet, uppger Kyodo enligt TT.

Japan har tidigare idag utfärdat undantagstillstånd på kärnkraftverket.

13.06: Undantagstillstånd har utlysts kring kärnkraftverket i Fukushima, som har nedkylningsproblemen. Kabinettssekreterare Yukio Edano betonade dock att det inte råder någon fara för personer i omgivningen, enligt TT.

– Vi har utlyst ett kärnkraftsnödläge eftersom vi måste vidta alla tänkbara åtgärder. Men låt mig upprepa att det inte finns någon radioaktiv läcka och det kommer heller inte att bli någon, sade Edano på en presskonferens.

– Vi uppmanar alla som bor nära kraftverk att agera lugnt.

12.11: Japan har utfärdat undantagstillstånd vid ett kärnkraftverk på grund av problem med nedkylningsanordningen, Men det ska inte råda risk för radioaktivt läckage, skriver AP.

Enligt Sky News, som hänvisar till japansa myndighetskällor, klarar man inte av att pumpa in nedkylningsvattnet i reaktorerna.

12.02: Branden i kärnkraftsverket i Onagawa pågår fortfarande, och det är oklart om det finns risk för radioaktivt läckage. I ett annat japanskt kärnkraftverk, i Fukushima, har en automatisk nedkylningsenhet aktiverats, enligt AFP som hänvisar till nyhetsbyrån Kyodo.

Svenska experter bedömmer dock att skalvet och tsunamin inte utgör någon risk för en kärnkraftsolycka i någon av de kärnkraftsanläggningar som ligger nära skalvområdet.

– Jag kopplar inte omedelbart till att det här skulle vara ett allvarligt hot mot säkerheten, enligt den rapportering jag sett hittills. Jag kan inte se att det är något att vara orolig för, säger Lars Gunsell, utredare vid Strålsäkerhetsmyndigheten, till TT.

Enligt honom är japanska kärnkraftverk kraftigt byggda och dimensionerade för att klara en jordbävning. Individuella bedömningar av jordbävningsrisken görs för varje enskild anläggning.

10.56: En brand har brutit ut vid ett kärnkraftverk i Onagawa i nordöstra Japan, uppger nyhetsbyrån Kyodo enligt TT. Det finns ingen information om hur omfattande branden är. Bolaget som driver kärnkraftverket har inte rapporterat om några problem vid kraftverket, uppger Reuters.

FN:s atomenergiorgan IAEA sade samtidigt att alla kärnkraftverk i närheten av skalvområdet stängts av, rapporterar TT.

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Det vi ved med säkerhet är alltså att de drabbade reaktorerna har stoppats. Om branden vid Onagawa har någon säkerhetsmässig påverkan är omöjligt att säga. Men det finns väldigt mycket som kan brinna på ett kärnkraftverk som inte har något som helst med reaktorn att göra(tex branden vid Krümmel som fick stort genomslag i media för några år sen trots att den var helt ofarlig).  Eftersom ingen rapportering säger att det är något problem med kylningen i Onagawa så är branden förmodligen inte något att oroa sig för.

Vad som händer i Fukushima har potential att vara allvarligare. Rapporteringen säger att de har problem med kylningen och att nödkylningssystemen kickat igång.  Så länge nödkylningssystemet fungerar som det ska är det inte heller något att oroa sig för. Risk för att härden kommer skadas finns om nödkylningssystemet av någon anledning strular, då kan det eventuellt leda till att bränsle överhettas och i det mest allvarliga fallet börjar smälta. I värsta fall kan det alltså bli ett nytt Harrisburg, om man spekulerar vilt och nödkylningsystemen havererar etc. Evakueringen är nog i detta läget enbart en väldigt konservativ säkerhetsåtgärd.

Det är viktigt att poängtera att innan situationen kan bli en fara för omgivningen så krävs flera saker. Nödkylningsystemet måste slås ut och förbli utslaget så att härden kan smälta ända tills den ätit sig igenom det tjocka stålet som utgör reaktorkärlet. Efter det fångas härden upp i inneslutningen som är designad för att kunna hantera en härdsmälta, det övertryck det ger upphov till odyl. Endast om även inneslutningen är allvarligt skadad kan något läcka ut. Inneslutningarna är rigoröst designade för att kunna hantera jordbävningar.

Vi följer vad som sker och kommer uppdatera bloggen löpande.

Länkar

http://dn.se/nyheter/varlden/jordskalv-skakar-tokyo
http://www.bbc.co.uk/news/world-asia-pacific-12709598
http://www.nyteknik.se/nyheter/bygg/byggartiklar/article3124064.ece
http://www.svd.se/nyheter/inrikes/svd-rapporterar-minut-for-minut_5998923.svd
http://www.businessinsider.com/fukushima-nuclear-plant-2011-3
http://www.guardian.co.uk/world/2011/mar/11/japan-declares-nuclear-emergency-quake