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Fukushima Dai-ichi nuclear plant: Reactor vessel integrity may be compromised

March 26, 2011

Leakage of water with high levels of radioactivity  raise the possibility that there may be cracks in the reactor containment vessels of Reactors #1,2 and 3.  One saving grace is that the pressure in the vessels remains high and would argue against a breach. However cracks below the water level that permit some water seepage  cannot be ruled out. It is also possible that the leakage of radioactive water is not from the vessel itself but from some of the surrounding valves or piping.

The Guardian:

A suspected break in the core of a nuclear reactor could have been responsible for a leak of large amounts of radioactive contamination at the Fukushima Daiichi power plant, Japanese nuclear safety officials said on Friday, in another setback to efforts to avert disaster at the stricken facility.

In the latest developments, officials have said seawater outside one of the units has registered 1,250 the normal level of radiation, while efforts are under way to pump radioactive water that has pooled around the reactor turbines into safe storage. The BBC has reported that short-term radioactive iodine has been detected at very high levels in the Pacific Ocean near the plant.

US naval barges have started rushing in supplies of fresh water amid concerns the seawater being used to cool down the reactors might be causing corrosion. …

On Thursday three workers were exposed to unusually high levels of radiation after stepping in contaminated water in the turbine building of the crippled No. 3 reactor, which they were trying to cool.

Two received possible beta ray burns to their legs. All three have been transferred to a special radiation treatment facility. Kyodo news reported that the two more seriously injured workers could have suffered internal radiation exposure.

“The contaminated water had 10,000 times the amount of radiation as would be found in water circulating from a normally operating reactor,” said Hidehiko Nishiyama, a spokesman for Japan’s nuclear safety agency.

Nishiyama said it was unlikely that the reactor had cracked, but conceded that the unusually high levels of radiation appeared to have originated from its core. “It is possible there may be damage somewhere in the reactor,” he said, adding that a leak in the plumbing or the vents could also be to blame.

GE BWR cutaway : image inside.mines.edu

NHK World reports:

A high level of radioactive iodine has been detected in seawater near Japan’s troubled Fukushima Daiichi nuclear power plant. The facility was hit by the March 11th earthquake and tsunami.

The Nuclear and Industrial Safety Agency said on Saturday that iodine 131 in excess of 1,250 times regulated standards was found in seawater collected 330 meters south of a plant water outlet at 8:30 AM on Friday.

The agency says there is no immediate threat to people within the 20-kilometer evacuation zone. The agency adds that as seawater is dispersed by ocean currents the contamination level will decline.

Iodine 131 at146.9 times regulated standards was detected in seawater in the area on Wednesday.

Saturday, March 26, 2011 12:44 +0900 (JST)

Kyodo News:

TEPCO, is currently injecting fresh water into the No. 2 reactor core to prevent crystallized salt from seawater already injected from forming a crust on the fuel rods and hampering the smooth circulation of water, thus diminishing the cooling effect. It has begun injecting fresh water into the No. 1 and No. 3 reactor cores.

At the same time, the firm is trying to remove pools of water containing highly concentrated radioactive substances that may have seeped from either the reactor cores or the spent fuel pools, while also trying to restore power at the No. 2 reactor.

On Thursday, three workers were exposed to water containing radioactive materials 10,000 times the normal level at the turbine building connected to the No. 3 reactor building. On Friday, a pool of water with similarly highly concentrated radioactive materials was found in the No. 1 reactor’s turbine building, causing some restoration work to be suspended.

Similar pools of water were also found in the turbine buildings of the No. 2 and No. 4 reactors, measuring up to 1 meter and 80 centimeters deep, respectively. Those near the No. 1 and No. 3 reactors were up to 40 cm and 1.5 meters deep. ..

The U.S. Department of Energy said in its radiological assessment released Friday that by comparing aerial measurement data from Thursday with previous measurements, the data indicate peak exposure rates in the western side of the Fukushima plant are lower.

 

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Radioactive water leaks from 3 reactors – fresh water cooling started

March 25, 2011

The path to complete cooling and stability will not be smooth or easy at Fukushima Dai-ichi nuclear plant. New complications and setbacks in Reactors #1,2 and 3 are leading to new strategies and actions. There will no doubt be many more such challenges in the days and weeks ahead.

Update 25th March midnight JST (1600 CET):

TEPCO said Friday it has begun injecting freshwater into the No. 1 and No. 3 reactor cores at the crisis-hit Fukushima Daiichi nuclear plant to enhance cooling efficiency, although highly radioactive water was found leaking possibly from both reactors as well as the No. 2 reactor.

The latest efforts to bring the troubled reactors at the plant under control are aimed at preventing crystallized salt from seawater already injected from forming a crust on the fuel rods and hampering smooth water circulation, thus diminishing the cooling effect, the plant’s operator said.

A day after three workers were exposed to water containing radioactive materials 10,000 times the normal level at the turbine building connected to the No. 3 reactor building, highly radioactive water was also found in the turbine buildings of the No. 1 and No. 2 reactors.

Early Friday, concern grew that the high-level radiation leak detected with the workers’ exposure Thursday could indicate possible damage to the No. 3 reactor vessel, but the government’s nuclear safety agency later denied the possibility, saying no data, such as on the pressure level, have suggested the reactor vessel has cracked or been damaged. The No. 3 reactor used plutonium-uranium mixed oxide fuel for so-called ”pluthermal” power generation.

While the high-level radiation is suspected to have come from the reactor, where overheating fuel rods are believed to have partially melted, it remains uncertain how the leak occurred, said Hidehiko Nishiyama, spokesman for the government’s Nuclear and Industrial Safety Agency.

He said further verification is needed to find out how the radioactive water reached the underground site where the workers were exposed. Huge volumes of water have been poured into the reactor as well as its apparently boiling spent fuel pool since they lost their cooling functions.

In addition to the infusion of freshwater to the No. 1 and No. 3 reactors, it injected seawater to the spent fuel pools of the No. 2 and No. 4 reactors through pipes, and firefighters sprayed a massive amount of seawater onto the No. 3 fuel pool, the utility said.

The government, meanwhile, encouraged residents within 20 to 30 kilometers of the plant to leave voluntarily, citing concerns over access to daily necessities, while maintaining its directives for them to remain indoors and for residents within 20 km of the plant to evacuate.

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Fukushima Dai-ichi nuclear plant: Status on March 25th

March 25, 2011

It is 2 weeks today since the quake and Tsunami struck. The toll of dead and missing exceeds 27,000.

Progress continues steadily but painfully slowly at the Fukushima Dai-ichi nuclear plant. The radiation levels are fluctuating but pose no health hazard to the general public. Containment vessel at Reactor #3 is damaged and may be causing radiation spikes.

From JAIF

  • The work to restore external AC power for units-1, 2, 3 and 4 is in progress. External AC power to the main control room at unit-2 will be available today. According to TEPCO, the reactor surface temperature at unit-1 increased to  approx. 400 ° C once (design assumption maximum 302 ° C).  Now it has dropped to 204.5 ° C (as of 06:00 on March 25).
  • Meanwhile,  in the turbine building at unit-3, drainage work is also in progress. (10:45, March 25)
  • On March 24, 2 workers, who were working to lay electrical cables in turbine building at unit-3, were sent to the hospital. TEPCO suspected that the nuclear fuel in the reactor or spent nuclear fuel at the pool was damaged and water contaminated with high radioactivity was leaked  to the workspace. Further investigation is now carrying on. These 2 workers were not wearing boots. Another worker wearing boots is safe. (07:15, March 25).
  • As for the coolant of reactors at Fukushima Daiichi, TEPCO would like to switch from seawater to fresh water as fast as possible. The first switch will be carried out at unit 3. (04:30, March 25)
  • Ministry of Defense announced that the Self-Defense Force helicopter measured the surface temperatures of Fukushima Daiichi units-1, 2, 3 and 4 from the air by using infrared rays and  found that the temperature of each units is below 20 ° C. Unit-1:17 ° C; Unit-2: 13°C; Unit-3: 11 °C; Unit-4: 17 °C (as of the morning on March 24). Especially, the surface temperature of the spent fuel pool at unit-3 dropped significantly to 31 °C, compared to 56°C on the previous day. (21:15, March 24)

From IAEA:

Unit 1: Workers have advanced the restoration of off-site electricity and lighting in the Unit’s main control room was recovered as of 24 March, 11:30 UTC. They are now checking the availability of the cooling system. While the pressure in the reactor vessel remains high, Japanese authorities are reporting that it has stabilized.

Unit 2: Engineers are working for the recovery of lighting in the main control room, and the instrumentation and cooling systems.

Unit 3: Around 120 tonnes of seawater was injected in the spent fuel pool via the cooling and purification line. The operation was carried out between 23 March, 20:35 UTC and 24 March, 07:05 UTC. Work was under way for the recovery of the instruments and cooling systems. However, it had to be suspended because three workers were exposed to elevated levels of radiation on 24 March.

Unit 4: The spent fuel pool was sprayed with around 150 tonnes of water using concrete pump truck. The operation was carried out between 24 March, 05:36 UTC and 06:30 UTC of the same day.

Units 5 and 6: Repair of the temporary pump for Residual Heat Removal (RHR) was completed as of 24 March, 07:14 UTC, and cooling started again 21 minutes later.

At the Common Spent Fuel, the power supply was restored as of 24 March, 06:37 UTC and cooling started again 28 minutes later. Work is now under way for the recovery of the lighting and instrumentation systems. As of 24 March, 09:40 UTC, the water temperature of the pool was around 73 °C.

As of 24 March, 10:30 UTC workers continue to inject seawater into the reactor pressure vessels of Units 1, 2 and 3 and are preparing to inject pure water.

 

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Media coverage dies as work resumes at Fukushima Dai-ichi – steam plumes did not raise radiation levels

March 22, 2011

Fukushima hysteria dies down as the media find that their alarmist and sensational reporting is not going to be sustainable.

Perhaps they will return their attention and their headlines to the victims of the earthquake and the tsunami in between the bombing raids on Tripoli.

As George Monbiot puts it in The Guardian:

As a result of the disaster at Fukushima, I am no longer nuclear-neutral. I now support the technology.

A crappy old plant with inadequate safety features was hit by a monster earthquake and a vast tsunami. The electricity supply failed, knocking out the cooling system. The reactors began to explode and melt down. The disaster exposed a familiar legacy of poor design and corner-cutting. Yet, as far as we know, no one has yet received a lethal dose of radiation.

Now George Monbiot’s views about energy in general, and renewables in particular, are usually quite ridiculous and ill thought through but  where he is absolutely right is of course that in spite of the headlines and the apocalypse scenarios, “no one has yet received a lethal dose of radiation”.

The work at Fukushima is difficult and hazardous  and it will test the courage and ingenuity of many – but it goes on even if all the headlines are gone     —– Kyodo News:

Work to restore power and crucial cooling functions resumed Tuesday morning at the crisis-hit reactors at the quake-stricken Fukushima Daiichi nuclear power plant, following suspension Monday after smoke was detected at its No. 2 and No. 3 reactors, its operator said.

Firefighters and the Self-Defense Forces also prepared to restart a mission later in the day to spray a massive amount of coolant water onto spent nuclear fuel pools at the No. 3 and No. 4 reactors, according to Tokyo Electric Power Co.

Although white smoke, possibly steam, was found to be continuously billowing from the buildings of the No. 2 and No. 3 reactors, the utility known as TEPCO found it does not obstruct electricity restoration work as radiation levels did not particularly surge at the site.

An external power source was connected to the No. 4 reactor in the morning, making it the fifth of the plant’s six reactors to have regained a power supply needed for the restoration of equipment such as a ventilation system to filter radioactive substances from the air and some measuring tools at the control room.

TEPCO aims to restore power systems to revive some key facilities such as data measuring equipment and functions at a control room by Wednesday for the No. 1 and No. 2 reactors and by Thursday for the No. 3 and No. 4 reactors, said Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, at a press conference.

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Fukushima Dai-ichi plant: Work stopped as steam rises from reactors # 2 and 3

March 21, 2011

Work to connect power cables to the No. 3 and No. 4 reactors was halted Monday at the crisis-hit Fukushima Daiichi nuclear power plant, after smoke rose from the buildings housing the No. 2 and No. 3 reactors, the plant operator said.

TEPCO said it had briefly evacuated its workers after grayish and blackish smoke was spotted at the southeast of the No. 3 reactor building around 3:55 p.m. above a pool storing spent nuclear fuel, though a blast was not heard.

The smoke stopped after 6 p.m., but TEPCO subsequently found that white smoke was rising through a crack in the roof of the building that houses the No. 2 reactor at around 6:20 p.m. The utility said later the smoke is believed to be steam, not from the reactor’s fuel pool. As the No. 3 reactor remains without power, smoke was not apparently triggered by an electricity leak or short-circuiting.

The government’s Nuclear and Industrial Safety Agency said no injuries were confirmed in the incidents and that there have been no major changes in the radiation levels at the site.

Before the smoke was detected, external power had reached the power-receiving facilities of the No. 2 and No. 5 reactors on Sunday, clearing the way for the plant operator to restore systems to monitor radiation levels and other data, light the control rooms and cool down the reactors and their spent-fuel storage pools. On Monday, TEPCO finished laying cables to transmit electricity to the No. 4 reactor, as a step toward resuscitating the power systems at the No. 3 and No. 4 reactors, according to the utility and the nuclear agency.

International Atomic Energy Agency Director General Yukiya Amano told a special meeting of its board of governors that the situation at the Fukushima plant ”remains serious, but we are starting to see some positive developments.”

Tokyo Electric Power Co. said it will resume the operation on Tuesday after observing the situation at the site.

 

 

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Fukushima Dai-ichi nuclear plant: Status as of Monday (21st) morning

March 21, 2011

Status of Fukushima Daiichi power station as of 09:00, March 21, 2011

Cooling continues and power is gradually being brought to all reactors. Systems and equipment are being checked. All units now have surface temperatures of less than 100 °C. Reactors # 5 and 6 have acieved “cold shutdown”.

External power reached the power-receiving facilities of the No. 2 and No. 5 reactors on Sunday.

The government is also preparing SDF tanks to remove radioactive rubble from around the reactors that has hampered operations as well as a truck with a concrete squeeze pump to pour water from a higher point.

Reactors # 5 and 6 have achieved the status of “cold shutdown”.

Developments at Fukushima Daiichi on March 21st

  • Injecting water to the spent fuel pool at unit 3 of Fukushima Daiichi by Tokyo Fire Department’s task force was finished at around 04:00 am this morning after 6.5 hours operation. Unit 3 has been sprayed with over 3,700 tons of water on Sunday and Monday.
  • Then, the Self-Defense Force conducted the operation of injecting water to the spent fuel pool at unit-4 from 06:37 am to 08:30 am this morning.
  • A construction company in Mie Prefecture voluntarily offers assistance for water injection at Fukushima Daiichi. The government emergency headquarters decided to accept the offer. The company’s 2 special vehicles and 3 operators departed last night to the site. The vehicles can inject water by using its 50-meter-long arm and pumps.
  • Ministry of Defense announced that the Self-Defense Force helicopter measured the surface temperatures of Fukushima Daiichi from the air and found that the temperature of all units are below 100 degrees C.
    • Unit 1: 58 ° C;
    • Unit 2: 35 ° C;
    • Unit 3: 62 °C;
    • Unit 4: 42 ° C;
    • Unit 5: 24 ° C;
    • Unit 6: 25 °C. (as of the afternoon on March 20)

Yesterday the Nuclear and Industrial Safety Agency reported that the pressure of the Reactor Containment Vessel at unit 3 of Fukushima Daiichi rose once (to 320 kPa as of 11:00 March 20th). TEPCO prepared to lower the pressure but concluded immediate pressure relief was not required. Monitoring the pressure continues (225 kPa as of 22:00 March 20).

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Fukushima Dai-ichi Sunday 20th March: Power has reached reactor#2, plant will be decommissioned

March 19, 2011

Day No. 9 since the quake and tsunami.

Media hysteria is abating as the crisis  abates and Libya take s over the headlines.  “It is becoming more probable by the day that public health consequences will be zero and radiation health effects among workers at the site will be so minor as to be hard to measure”.

On Saturday, workers were close to restoring power to cooling systems at a quake-hit Japanese nuclear power plant. Fire trucks sprayed water for nearly half a day on reactor No.3.

“The situation there is stabilizing somewhat,” Chief Cabinet Secretary Yukio Edano told a news conference.

2400 JST (1600 CET): Known status by IAEA:

It would seem that the current critical  actions with the nuclear plant are connected – for now – with the spent fuel pools.

Unit 1 experienced an explosion on 12 March that destroyed the outer shell of the building’s upper floors. No precise information has been available on the status of the spent fuel pool.

For unit 2, no precise information has been available on the status of the spent fuel pool. Authorities began adding 40 tonnes of seawater to the spent fuel pool on 20 March.

Concerned by possible loss of water in the Unit 3 spent fuel pool, authorities began spraying water into the building in an effort to replenish water levels. First, helicopters dropped seawater on 17 March, and every day since then, including today, emergency workers have sprayed water from fire trucks and other vehicles.

Emergency workers began spraying water into the Unit 4 building today.

Temperatures in the spent fuel pools of Units 5 and 6 have gradually returned to significantly lower temperatures.


2230 JST ( 1430 CET): Status – Fukushima No. 5, No. 6 reactors stable after cold shutdown.

External power was restored at 3:46 p.m. to the reactor #2. Work is now ongoing to  start trying to restore the system to monitor radiation and other data, light the control room and cool down the reactor and the reactor’s spent-fuel storage pool.

Water spraying by fire trucks continues for cooling the overheating spent fuel pools by throwing thousands of tons of water into the No. 3 and No. 4 reactor buildings. The operation is possible because apparent hydrogen explosions blasted the roofs and walls of the buildings.

As of 11:00 a.m., Tokyo Electric said the radiation level about 0.5 kilometer northwest from the No. 2 reactor dropped to 2,579 microsievert per hour, compared to 3,443 microsievert per hour at 2 p.m. Saturday.

1830 JST (1030 CET): Water spraying on reactor #4 again (2nd time today). Sounds like some danger of radioactive leakage from the spent-fuel pond is persisting.

Status summary (BBC)

  • Reactor 1: Fuel rods damaged after explosion. Power lines attached
  • Reactor 2: Damage to the core, prompted by a blast, helped trigger raising of the nuclear alert level. Power lines attached
  • Reactor 3: Contains plutonium, core damaged by explosion. Fuel ponds refilled with water in overnight operation, but pressure said to be rising again
  • Reactor 4: Hit by explosion and fire, temperature of spent fuel pond now said to have dropped after water spraying
  • Reactors 5 & 6: Temperature of spent fuel pools now lowered after rising dangerously high. Diesel generators powering cooling systems

1800 JST (1000 CET): Power has “been supplied” to reactor #2 says Kyodo news. It is not clear if the power now available has succeeded in starting up cooling pumps or just that power is now available at reactor #2. Nevertheless a huge leap forward.

The Fukushima Daiichi nuclear power plant is most likely to be decommissioned. ”Looking at the situation objectively, it is clear,” Chief Cabinet Secretary Yukio Edano said at a news conference, when asked whether the government plans to decommission the plant.

1600 JST (0800 CET): Current evacuation area not expected to change according to Japan’s Nuclear Agency.

Spent-fuel storage pools of the reactors No. 5 and No. 6 were cooled down to 37.1 °C and 41.0 °C, respectively, as of 7 a.m. Sunday.

More than 2,000 tons of water is believed to have been sprayed onto the No. 3 reactor’s pool, which has a capacity of 1,400 tons. Pressure at No. 3 reactor’s containment vessel suppression pool rose and plans to reduce pressure by venting were planned but the pressure stabilised and immediate work to reduce pressure at No. 3 reactor at Fukushima plant was deferred.

Fears of radiation release led to Ground Self-Defense Force spraying about 80 tons of water on reactor #4 for nearly one hour until 9:30 a.m., according to the Defense Ministry. Eleven fire trucks were used. Indications are that that water reached the pool.

Work to connect power and restart cooling pumps at reactor #2 is continuing.  It is planned to check the systems of the No. 2 reactor first. The building housing its containment was not damaged, which means it is hard to cool it down using water from outside.

0800 JST( 0000 CET): On Saturday and the early hours of this morning water spraying was carried out for a total of 13 hours (till about 5am on Sunday morning). The water temperature in the spent fuel pond of reactor #6 has fallen.

Power company engineers finished connecting the No.1 and No.2 reactors to external sources on Saturday evening.

Technicians seem to have attached a power cable to the No. 1 and No. 2 reactors, hoping to restore electricity later today prior to an attempt to switch the pumps on. Equipment checks are probably being conducted now.They aim to reach No. 3 and 4 soon after that.

The Register writes:

The situation at the Fukushima Daiichi nuclear powerplant in Japan, badly damaged during the extremely severe earthquake and tsunami there a week ago, continues to stabilise. It is becoming more probable by the day that public health consequences will be zero and radiation health effects among workers at the site will be so minor as to be hard to measure. Nuclear experts are beginning to condemn the international hysteria which has followed the incident in increasingly blunt terms.

0100 JST (1700 CET 19th): IAEA  press conference on the situation at the Fukushima Daiichi nuclear power plant. It hopes that power will be restored to reactor 2 today, which will then act as a hub to restore power to reactor 1. However it is not clear if water pumps have been damaged and if they will even work once power has been restored.

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Fukushima Dai-ichi 19th March: “Nuclear crisis is abating step by step”

March 18, 2011

Saturday 19th March: Day 8 after the quake and tsunami

Geoeye before and after pictures from the New York Times

2330 JST (1530 CET): The spraying operation should have ended around now.

Internal cables are being completed.

1906 JST (1106 CET): A 6.1 magnitude quake about 20km down has hit Iberaki with shaking felt in Tokyo. No risk for a tsunami but the epicentre is not so far away from Fukushima.

1830 JST (1030 CET): The Chief Cabinet Secretary Yukio Edano said earlier today “The crisis is abating step by step”. No doubt he had his fingers crossed at the time. Worth bearing in mind that in spite of all the alarm and sensational reporting and alarmism, there are no deaths associated with the nuclear accident to date while the dead and missing from the quake and tsunami now number 20,000+. Some of the emergency workers (about 20) at the site have suffered some radiation exposure but at a relatively low level compared to Tjernobyl. Outside of the exclusion zone radiation levels are still miniscule.

Hidehiko Nishiyama, deputy director-general of the Nuclear and Industry Safety Agency, told reporters that a review of video shot from a helicopter and an on-the-ground check by a worker had confirmed that there is water in the spent fuel pool.

A seven-hour long water spraying exercise is ongoing. The current plan seems to be to start feeding power into reactors #1 and 2 early Sunday and also to reactors # 3 and 4 later on Sunday. Could be coincidence but it seems that all planned actions on the power reconnection are always preceded by a water spraying exercise and never carried out while water spraying is ongoing. Perhaps the water spraying reduces local radiation levels so as to permit longer working shifts in the exposed zones. The current spraying exercise will continue till about 2300 local time.

1730 JST (0930 CET): According to government quake-hit Oshika Peninsula moved 5.3 meters, dropped 1.2 meters.

1600 JST (0800 CET): Spraying has restarted and will continue now for 7 hours. SDF troops and fire fighters are together trying to set up a round the clock spraying capability. Reactors #5 and 6 are each being cooled by one of their own diesel powered pumps.

Press Conference by Chief Cabinet Secretary : Reactors # 1, 2 and 3 have been subject to sea water cooling and are somewhat stable. We believe the spray water has reached the reactor #3 spent fuel pond and this has also stabilised and spraying will continue for reactors #3 and 4. Further actions using additional equipment are planned once the situation has stabilised. The crisis is abating step by step.

Within Fukushima and Iberaki prefectures some milk and spinach had radiation levels above the limits set by the Food Safety Law. Today 6 samples of spinach had high radiation levels. Further investigations will continue and the prefecture governments will prevent transport of these.The radiation levels in these products would mean that continuous consumption for a year would be just equivalent to a CT scan. The detected levels are above permissible levels but are not an immediate health hazard. Detailed information will be provided by the Ministry of Food.

1530 JST (0730 CET): While the new high voltage power line is connected to a transformer within the plant perimeter, the path from there to the reactor#1 and 2 transformers was blocked by debris and an extra 1500 m of power line around the perimeter of the plant to the reactor transformers has to be installed. This power is unlikely to be switched on before late Saturday. The cooling pumps which were subbmerged by the tsunami have still to be checked out.

1500 JST (o700 CET): A diesel cooling pump was restarted at reactor #5 a few hours ago and the temperature in reactor #5’s spent fuel pond has decreased. A diesel generator at reactor#6 has also been restarted.

The radiation level at the west gate of the plant, located about 1.1 kilometers west of the No. 3 reactor, was relatively high at 830.8 microsieverts per hour at 8:10 AM but fell to 364.5 microsieverts at 9:00 AM.

Starting at noon some 30 tons of water were sprayed onto reactor #3.

Engineers have bored holes in the roofs of the buildings housing # 5 and 6 to avoid any hydrogen explosions.

The new power line is still not fully connected or in operation yet but the hope is that power can be turned on later today to reactor #2.

0800 JST (0000 CET): Checks are presumed to be ongoing before any attempt to turn power back on. Not only must the equipment integrity be checked but the possibility of short circuits and any volatile matter which could ignite must be eliminated as well. The next round of spraying will be at noon.

0600 JST (2200 CET): Reuters reports: Working inside a 12 mile evacuation zone at Fukushima, nearly 300 exhausted engineers were focused on trying to restore power at pumps in four of the reactors.
Another 1,480 meters (5,000 feet) of cable are being laid inside the complex before engineers try to crank up the coolers at reactor No. 2, followed by 1, 3 and 4 this weekend, company officials added. Should that work , it will be a turning point. “If they can get those electric pumps on and they can start pushing that water successfully up the core, quite slowly so you don’t cause any brittle failure, they should be able to get it under control in the next couple of days,” said Laurence Williams, of Britain’s University of Central Lancashire.

0500 JST (2100 CET): TEPCO has checked out the power line upto the receiving point at reactor #2 and confirmed that power can now be supplied. Presumably some equipment checks must be done before turning the power on.

0400 JST ( 2000 CET 18th): TEPCO says it has now connected an external power line to its stricken plant and would first supply reactor 2 because it is less damaged, Reuters reports. The power is from Tohoku Electric.

0230 JST (1830 CET):  TEPCO has appointed Vice President Norio Tuzumi and Managing  Director Akio Komori to be stationed at Fukushima City and J Village respectively from March 22, 2011. Tuzumi will be responsible for ensuring that TEPCO takes in the opinions and views of the loacl people and Komori will be responsible for safety and the prevention of further damage.

The operation to douse the overheating fuel rods at Fukushima resumed early on Saturday. Five specially-equipped engines from the department poured seawater for 20 minutes so as (to allow the work for connecting the power line to continue) says NHK.

0000 JST (1600 CET):  Graham Andrew of the IAEA: “The situation at Fukushima Daiichi nuclear power plants remains very serious but there has been no significant worsening since our last briefing” on Thursday.

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TEPCO was ready to give up and abdicate on 14th March

March 18, 2011

The Mainichi Daily News carries this story. Even in the unprecedented situation after the quake and tsunami and with the nature of the radiation risks involved the reaction of some of the TEPCO employees is understandable; but that TEPCO as a Corporation was ready to give up and ask the SDF to bear all the risks smacks of Corporate cowardice and does not say much for the Corporation’s values:

Tokyo Electric Power Co. (TEPCO) told the government on March 14 that it wanted to withdraw all of its workers from the Fukushima No. 1 nuclear power plant, it has been learned.

TEPCO’s suggestion came two days after a cooling system failure caused by the March 11 quake and tsunami triggered a hydrogen blast at the plant’s No. 1 reactor. Though Prime Minister Naoto Kan rejected the proposal, the finding suggests that the power company was aware from an early stage that damage at the plant could develop into a nuclear disaster exposing workers to high levels of radiation. It is believed that TEPCO was prepared to let Japan’s Self-Defense Forces and the U.S. military handle the situation.

Several government sources said that TEPCO officials told Chief Cabinet Secretary Yukio Edano and Economy, Trade and Industry Minister Banri Kaieda over the phone that the company wanted to withdraw all of its workers. Both government officials turned down the requests and reported them to Kan.

Shortly after 4 a.m. on March 15, Kan summoned TEPCO President Masataka Shimizu to the Prime Minister’s Office and told him pulling out was not an option. He added that a joint countermeasures headquarters would be set up.

Afterwards, the prime minister visited TEPCO’s head office in Tokyo and said, “This is not a matter of TEPCO going under; it’s about what will become of Japan.”

Government officials confirmed that TEPCO’s suggestions on the night of March 14 indicated the company wanted to pull out all of its workers.

At the same time complaints are smoldering within TEPCO over Kan’s response. TEPCO officials said that the company has 4,000 to 5,000 workers at the plant, including those from cooperating firms, but now only about 300 remain. They are working to control and restore power-generation stations.

“Saying, ‘I won’t allow you to pull out,’ is like saying, ‘Get exposed to radiation and keep going until you die,'” one member of the company commented.

TEPCO could well have allowed all workers who wished to do so to leave the plant while bearing their corporate responsibility. I am quite sure that there would have been many TEPCO employees who would have volunteered for emergency operations. Masataka Shimizu and TEPCO are no Samurai – but perhaps that is no longer a reasonable expectation. It does seem as if the military are now in control.


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Fukushima Dai-ichi diary for Friday 18th: Radiation decreasing – Is the worst over?

March 17, 2011

Today will be one week since the Great Sendai quake and the subsequent tsunami slammed north east Japan. Today will also be a fateful day for the efforts being made to cool the reactors and the spent fuel ponds at the Fukushima Dai-ichi nuclear plant. Though the nuclear plant incident causes much more alarm than anything else the quake and tsunami caused, it is worth bearing in mind that it is still just an incident at the nuclear plant. Radiation leakage has not itself caused any deaths or any destruction so far. If unchecked it has the potential of becoming a disaster but if the eforts to cool the reactor today succeed then it will remain at the level of a very serious nuclear incident caused by the quake and the tsunami.

It needs to be remembered that the massive death and destruction was caused by the quake and the tsunami and has resulted  in 20,000+ killed or missing and the wiping out of whole towns. Over 500,000 are displaced and some have lost everything they owned and many of their families. The nuclear plant incident should not be allowed to divert attention from the dire condition further north.

(Sources for my diary are mainly NHK, Kyodo, Asahi, Reuters, BBC, CNN, AFP, IAEA, JAIF and  a few private sources. Some interpretation of the news reports is necessary since they all seem to have some bias.)

2200 JST (1400 CET): Sendai Airport has been cleared with the help of US forces and is now being used to fly in relief supplies. Considering the pictures of the tsunami wave flowing across the airport one week ago, that itself is remarkable. It is still very cold tonight for the evacuees but warmer weather is expected tomorrow.

No further news conferences scheduled today and no further news which at least means no further deterioration. If power is restored to the nuclear plant during tonight the corner would have been turned, I think.

2100 JST (1300 CET): It looks like water spraying activities are over for the day and the focus is back on connecting the new high voltage power line. Current effort is to connect to a transformer in the reactor building but work times are very short since the radiation level here is about 20 milli Sieverts / hr. Tokyo police and fire fighters are trying to devise a system which allows spraying for long periods using the high capacity fire trucks designed for tall buildings.

A small reduction in radiation was observed when spraying was finished but assessment will take some time.

A description of the quake, tsunami and consequences for the plant operation are well described here.

1900 JST (1100 CET): The authorities are warning of tidal floods in the north east. Due to the earthquake, parts of the coast have sunk and in some areas tides could be 40cm higher than usual. Spring tides will last 8 days but flooding will be slow compared to the tsunami.

1800 JST (1000 CET): Japan’s nuclear safety agency is now calling it a level 5 incident at reactors 1, 2 and 3 of Fukushima Dai ichi, and a level 3 incident at reactor 4. I think the incident at reactor no. 4 where the problems with the spent fuel pond have been so turbulent could be reclassified later to level 4. Three Mile Island was classified at level 5.

The Japanese nuclear agency says it expects electrical cables to be connected at reactors 1 and 2 by Saturday morning.

1700 JST (0900 CET): 5.4 magnitude quake off Ibaraki subjecting Tokyo to some shaking as well.

General Electric has sent nuclear engineers to a Japanese emergency response centre where they are working with Tokyo Electric Power Co. GE designs nuclear reactors, including all six at the Fukushima Dai-ichi plant though the plants were constructed by Toshiba.

Reuters reports that US data collection flights have confirmed that contamination has not spread beyond the 30km zone established by the Japanese Government — which of course begs the question why the US established 80 km as the no-go zone  for their citizens and which was immediately adopted by many other countries. Abundant caution is no doubt the reason but some accompanying explanation would have helped to prevent some of the questioning of the Japanese imposed 30km zone.

Chief Cabinet Secretary Edano explained that the water spraying operations were being carried out in shifts to limit exposure and the further spraying operations would be continuing as the personnel were rotated. No details about the effects were yet available but it seemed clear that the water was reaching the target.

1600 JST (0800 CET): In Severe Accident Management, the key step and that which is being carried out now is the use of water for the removal of heat. More stringent operations include the use of sand or rubble or boron in some form to cover the radiating components. It is not impossible to even consider concrete. But all uses of solid materials would limit any further heat removal and would only come into play if heat removal was considered impossible.

An SDF spokesman said  “We think got water on the main part today” and “Troops doing the work only absorbed a few millisieverts at most” says the Daily Yomiuri. The Assistant Head of the SDF said that the radiation levels did not significantly hamper the water spraying operations.

1500 JST (0700 CET): 7 days have gone since the quake hit.

More fire trucks including US military trucks are on their way. It will probably take a few hours to make any evaluation of the effects of the water spraying. But the amount of steam rising suggests that the water was reaching its target. But the amounts contained in the sprays (total around 50 tons) is small compared to the capacity of the spent fuel ponds (about 1200 tons). Water spraying is to continue.

There are some 180 people working at the site and braving the radiation levels.

1414 JST: 2 more water jets can be seen – apparently the 3rd wave. Steam continues to rise and is “billowing” rather than a plume.

1410 JST (0610 CET): The strong plumes of steam(?) have subsided somewhat and are now more like clouds rising.

1406 JST: One wave of water spray with 2 trucks seems to be over and plumes of steam(?) can be seen rising from the reactor. Something is being cooled.

1400 JST (0600 CET): Water spraying has resumed at reactor no.3 by the SDF. Seven trucks are being used. The water jets are clearly visible from NHK pictures from 30km away and – at least by eye – are much more accurately directed onto the building than yesterdays helicopter drops.

1300 JST (0500 CET): Radiation levels have been consistently falling at one measuring point since the water spraying on Thursday evening. The measurement location is at one station about 1km west of reactor no. 2. The radiation reading at 5 a.m. Friday came to 279.4 microsievert per hour, compared with 292.2 microsievert per hour at 8:40 p.m. At around 9am this was down to 271 micro Sieverts. Thursday. It is not certain that this was due to the water spraying but the situation is at least stable and is not deteriorating. The trend is encouraging.

This morning the focus has been on the power line installation and on Friday at 2pm the water spraying will restart. It seems it was not possible to do both simultaneously. The SDF fire trucks will address reactor no.3 and police fire trucks will be working on reactor no.1. More fire trucks have been despatched from Tokyo. The performance of the trucks is such that helicopter water drops are not being considered. Over 30 trucks are expected to be in operation including trucks especially designed to fight fires in very tall buildings with a water discharge point 22m above street level. But water spraying is only a stop-gap measure and the real stability will only come once the cooling systems and water circulation has been restored.

The new power cables are in place but they now have to be reconnected to the cooling system pumps once the pumping systems have been checked out. Working shift durations are still restricted by the radiation levels. Reactor no.2 systems could be connected sometime during Friday night. Reactors no. 3 and 4 will be next to be reconnected and this is targeted for Sunday.

0600 JST: Summary of the status by Japan Atomic Industry Forum is here Fukushima status 2200 17th March

IAEA Slide show on BWR’s and the Fukushima status is here

18th March – 0500 JST (2100 CET 17th): The spraying of water by the fire trucks (and possibly even the helicopter water dumps) on the evening of the 17th did give some small but measurable decrease in radiation levels at the gate of the power plant. Spraying activities stopped at around 8pm on 17th and will resume this morning. Hopefully the high voltage power line which has now been laid upto the plant can be activated and the cooling systems brought back into operation today. This work will be slow since exposure to radiation leads to very short working shifts. This could take till tomorrow. This makes the spraying operations particularly critical for today to win the time necessary to get the power restored. The plan is for engineers to reconnect power to unit 2 once the spraying of water on the unit 3 reactor building gives some effect. The water spraying operations are being carried out by SDF and police personnel and TEPCO has even come in for criticism from the SDF for insufficient information which could have endangered their personnel.

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