Fukushima watch 2011-03-31

Tomorrow it will be two weeks since I left Tokyo with my family. Every day we scan the news for clues for when it may be safe to return, but it’s not easy.

Achim Steiner, the executive director of the United Nations Environmental Program (UNEP) questioned why “clear, precise information” on the nuclear situation in Japan was so difficult to come by.

The IAEA advised the Japanse government to check the need for evacuation in Iitate village, some 40 km from Fukushima because levels of I-131 were too high. It was the environmental organisation Greenpeace and not the Japanese government that had first collected data there.

Radiation in seawater near the plant exceeds legal limits by 4385 times, the highest level ever. Ditches filled with radioactive water are within 10 cm of overflowing and sandbags and cement are being used to prevent them spilling.

Water injection into the partially uncooled overheated reactor cores has been cut back for fear of radiactive water leaking back out and obstructing efforts to restart electric cooling pumps. Some of the water inside the plant is radiating 1000 millisieverts per hour, exposing the workers to the recent raised maximum annual dose for nuclear emergencies (250 mSv) within only 15 minutes (or within 6 minutes before the raise).

Only the spent fuel pool at unit #1 has a concrete pump attached for topping up cooling water. Other pumps of the same type are to be flown in from Germany now. No spent fuel pool water temperatures are available for unit 1, 3 and 4 (which hold 292, 514 and 1331 fuel assemblies) because of “measuring instrument malfunction”. Only the temperature for the pool in #2 (with 587 assemblies) is known. Seawater was still being used for topping up pools, which means salt will accumulate when the water boils or evaporates

Fukushima holds 1780 tons of nuclear fuel, versus 180 tons in Chernobyl. The majority of that fuel is held in spent fuel pools which are outside the containment building. The pool in unit #4 holds the largest number and also the most radioactive of the spent fuel assemblies. Unit #4 shares its control room with unit #3, which looks the most damaged in aerial shots. Unit #4 itself has holes 8m by 8m in size in its wall.

The containment building at unit #2 is at or near atmospheric pressure (0.11 MPa absolute), indicating a crack or open valve. At least a portion of the fuel rods probably already melted through the pressure vessel onto the concrete floor of the containment.

Fukushima: A future cast in concrete

If, as seems increasingly likely, the cooling pumps can’t be restarted in each and every block of the Fukushima Daiichi nuclear power plant, we will lose all the blocks due to release of excessive radiation from whatever block melts down first. The only option left will be to seal the power station under a huge amount of concrete, a sarcophagus like in Chernobyl.

Two weeks after the quake and tsunami hit the plant, the situation is no better than it was, if anything it has deteriorated since then, despite how it has been spun by Tepco and the government in the Japanese mass media.

On the upside, external power has been restored to inside the control rooms and limited cooling has been established via splashing water from outside and injecting water through the fire extinguisher system. Freshwater is being used for that now, after nothing but seawater had been available for two weeks. The use of will relieve worries about problems from salt buildup inside the plants (over 100 tons of sea salt are supposed to have accumulated already).

On the downside, the basements of the turbine halls under units 1 through 4 were flooded with highly radioactive water (#1: 0.4m, #2: 1m, #3: 1.5m, #4: 0.8m). On Thursday three workers were injured while trying to replace a cable in the turbine hall basement for unit 3 when they walked in the water which had not been observed the day before. It contained a staggering 3.9 million becquerels of radioactivity per cubic centimeter which is 10,000 times the usual amount inside the reactor (or 13 million times the Japanese safety level for drinking water for adults). That water is now being pumped out, but Tepco is not sure how to dispose of it.

An analysis of radioactivity in water from the basement of unit #1 showed that most of the radioactivity (1.8 million becquerel) was from cesium-137, which has a half life of 30.2 years. This is much more long lived than iodine-131 (half life: 8 days), which so far dominated tests around Japan before. Besides cesium-137 the water in unit #1 contained cesium 134 (160,000 becquerel), cesium-136 (17,000 becquerel) and iodine-131 (210 000 becquerel). The dominance of cesium-137 is a major worry: While radioactivity from iodine-131 drops off rapidly within weeks and months, pollution from cesium-137 will be dangerous for decades and centuries.

Both cesium and iodine are fission products normally contained within the uranium oxide (or uranium/plutonium oxide in the case of unit #3) of the fuel rods inside zirconium alloy tubes held inside a thick steel pressure vessel (reactor core) inside a reinforced concrete containment vessel. In the case of spent fuel rod assemblies in the storage pools there is no pressure vessel or containment.

When the fuel rods overheat the zirconium alloy will melt at temperatures over around 1800C, allowing volatile fission products to diffuse out of he oxide tablets into the pressure vessel or the storage pool.

It is not clear if the highly radioactive water in unit 1, 2, 3 and 4 came from the reactor core or from a storage pool. In the latter case, there could either be a leak in the pool (it consists of a stainless steel liner inside a reinforced concrete structure) or the pool could have overflowed during attempts to refill it so it doesn’t boil until dry.

If the water came from the reactor core it could be due to a damaged containment and reactor core or it could be due to problems with the pipes or valves connecting the reactor to the adjacent turbine hall.

Either way the leaks make the turbine hall a hostile environment for technicians trying to restore the cooling system for the damaged reactors. The reactor cores in unit 1, 2 and 3 would have to be cooled for about the next 2 years to prevent the fuel rods from melting through the reactor core. This will be next to impossible to achieve without reactivating the cooling pumps and restoring their control system.

With significant damage to the fuel rods as presumed by Tepco, any primary cycle cooling water will be loaded with dangerous fission products. Dealing with leaks of coolant or bleeding pockets of air and gas from coolant pumps as needed before resuming pumping could expose workers to life threatening doses of radiation. Under these circumstances, if any of the pumps turn out to be damaged there is little prospect of being able to replace them, even if spare parts could be manufactured and brought in.

The bottom line is that getting proper cooling working again for all cores at Fukushima Daiichi is a long shot, especially considering how long the cooling will still be required. The power station units have been damaged so badly by overheating, hydrogen explosions and sea water flooding that time is running out. The more radioactive fission products are leaked, the more difficult it becomes for humans to work and survive inside the plant. There will come a point when all of Fukushima Daiichi is a death zone that no one can enter and get out again alive.

At that point the only option is to find a way to completely and permanently seal the plant off from air and water by entombing it inside concrete like the stricken block in Chernobyl. The reason Tepco has not started doing that yet is not that they’re still trying to salvage their property: Since seawater and boron was pumped into the reactor cores on the first weekend the reactors have already been beyond rescue, as boron is a “neutron poison” and seawater is highly corrosive. At best the reactors would have to be mothballed indefinitely after that. They could never have been restarted to provide power again.

Why then is Tepco not pouring concrete over the reactors yet? Partly the answer may be that it’s like trying to dismount a tiger one is riding. While the reactor is still exposed to the outside one can still try to do things like cooling it down with fire hoses or replenishing water in the spent fuel storage pool. Once it is partly buried under concrete that becomes more and more difficult. As a result radioactivity might spike before the concrete could securely enclose the mortally wounded reactors.

A durable sarcophagus in this earthquake zone not only requires ample quantities of concrete but also steel reinforcements, which is hard to do if humans aren’t safe near the reactors. This will be no ordinary construction job by any means. The construction effort may have to involve remote controlled vehicles and other novel engineering approaches.

A primitive approach could simply bury the entire plant area under a mountain of concrete, perhaps piled up via remote-controlled trucks and bulldozers, later sealed with a skin of reinforced concrete to deal with earthquakes.

One would hope that Tepco started work on various alternative plans for increasingly severe scenarios as soon as they realized the cooling systems failed on March 11. Unless a miracle happens and all reactor cooling systems can be restored quickly, a concrete “Mt. Fukushima” probably is the only way to save Eastern Japan or all of Japan from massive radioactive pollution.

UPDATE (2011-03-28):

The lack of discussion of the concrete sarcophagus solution by Tepco suggests they are still committed to a “Three Mile Island” solution: Try to reestablish adequate cooling, wait about 5 years and then open the containment and pressure vessel to remove the radioactive mess in the core, clean up the contamination in the building. In other words, they still see the accident as a TMI-like level 5 accident and hope to keep it there, even though both the French nuclear safety authority ASN and its counterpart in Finland have rated the accident as level 6 on the INES scale.

The gradual melt-down of cores 1, 2 and 3, the uncertainty about whether the containment of block 2 is cracked or not plus the problems with the spent fuel storage pools 1, 2, 3 and 4 raise serious questions about how realistic a TMI-type recovery and cleanup is.

Japanese nuclear crisis “only just starting”

The crisis at Fukushima Daiichi nuclear power plant has yielded the top news spot to the events in Libya for now, but it’s far from over. “Factually, the problem in Japan is only just starting, ” Sebastian Pflugbeil, a physicist and president of Gesellschaft für Strahlenschutz (Society for Radiation Protection, Germany) is quoted by German magazine Focus.

To secure Fukushima Daiichi, a total of 3 reactor cores (1, 2 and 3) and 4 spent fuel pools (1, 2, 3 and 4) need to be brought permanently under control. If any one of these cores or spent fuel pools goes into full melt down, high levels of radiation from destroyed fuel rod assemblies may pollute the reactor site so much that staff will be forced to indefinitely abandon the entire plant, including control rooms and cooling equipment of units currently in a semi-controlled state.

On Tuesday Tepco reconnected power to the damaged reactor blocks in Fukushima Daiichi, but it is still a long step from being able to turn on lights in control rooms to actually running massive cooling pumps in the damaged plant.

Keith Bradsher writes in the New York Times:

Preventing the reactors and storage pools from overheating through radioactive decay would go a long way toward limiting radioactive contamination. But that would require pumping a lot of cold freshwater through them.

The emergency cooling system pump and motor for a boiling-water reactor are roughly the size and height of a compact hatchback car standing on its back bumper. The powerful system has the capacity to propel thousands of gallons of water a minute throughout a reactor pressure vessel and storage pool.

These pumps first need draining of air pockets to be able to be operated again, which is a difficult process under ordinary conditions, when the core isn’t damaged yet and radioactivity in the water of the primary cooling cycle is relatively low. Now the risks to the technicians will be tremendous.

It has also been reported that the pumps in unit #2 are no longer usable and replacements have been ordered. Any effort to remove the dead pumps, move in new pumps and reconnect them to the piping is going to be a real challenge under current conditions.

A couple of days ago the first reports came in of low doses of radiation in drinking water in Tokyo, then still around 1% of legal limits. That was after winds for the first time since the accident had blown south from Fukushima towards the Kanto area, the flat plain surrounding Tokyo. Later they turned back out towards the sea.

This week the winds from the north returned. Radiation levels in drinking water in Tokyo that exceed Japanese legal limits for infants below one year old have now alerted many to the risks. Tap water should no longer be used to mix with infant formula, but stores have run out of bottled water. What are mothers going to do? Boiling does not destroy radioactivity. Tokyo gets much of its drinking water from dams in the mountains west of the city, such as Lake Okutama, which get replenished by rain.

The Kanto plain is home to about as many people as live in Canada, California or Spain. What are they going to do without safe drinking water?

For lack of available fresh water, sea water has been used for cooling at Fukushima for almost two weeks now. Each ton of sea water contains about 35 kg of salt, which stays behind when the water boils off or evaporates as steam. Gradually the inside of the reactor cores and storage pools will become silted or encrusted with solid salt. Sooner or later the efforts to cool the reactors won’t be sustainable without ample supplies of fresh water.

Time is running out in Fukushima.

See also:

Japan nuclear crisis: Seeking safety for my family

Dear friends,

it has not been an easy decision, but today I have purchased four airline tickets to Europe for my family.

One line of defense after another against nuclear disaster has fallen. After the fire in Fukushima Daiichi #4 and the damage to #2, the increased release of radiation, the talk of a damaged containment and the detection of nuclear fission products as far away as Tokyo and Kanagawa I have lost all confidence in the ability of the people in charge to protect the Japanese population from harm.

In a few days we will be leaving Japan to seek safety with my brothers and parents in my home country until the situation here becomes clearer.

Joe Wein

See also:

Power cuts hit Tokyo

The Japanese capital Tokyo will join other regions of Japan to share rolling power cuts. Each region will be cut off from power for 3 hours a day on a rotating schedule, with a different time every day. I probably will be offline in about half an hour, which means no computer usage, no Internet access, no Skype calls, no landline phone calls (I have an Internet phone line), no mobile calls inside the house (I have an internet femto cell base station), no flushing of toilets (too high tech), no shopping (cash registers), no refuelling (electric gas pumps).

The good news I’ll have time reading on good old paper.

Tokyo Electric Power Company (Tepco), the operator of the fatally injured nuclear power stations, until recently ran a campaign (“oru denka”) to get consumers to switch to only electricity. That means using it for hot water preparation, domestic heating, cooking, everything – not a gas pipe in the house. Not only was this totally un-ecological as about 60-70% of energy is lost when making electricity from heat sources like gas or oil (you burn three times more gas to cook electrically if the electric power is made from gas rather than using a gas cooker), it also meant laying all eggs in one basket. These super consumers of electric power now also put their load on a supply system over-strained by knocked out generating capacity.

Hopefully I will be online again in four hours. The power cuts may continue until next month, Tepco announced, but the real challenge will be the coming summer, when Japanese consumers usually turn on their air conditioners. With at least half of Tepco’s nuclear generating capacity knocked out the outlook is grim.

If only Japan had invested in Wind power and other renewable energy instead of 55 nuclear power stations, a fast breeder reactor and a plutonium recycling plant that alone cost $25 billion, which now have a questionable future.

Japan hit by major Earthquake

Today’s magnitude 8.9 earthquake 400 km from Tokyo was not business as usual. The Japanese are well prepared for quakes and building standards are high, but this quake is the strongest since scientific measurements have been available. It was shaking powerfully even here in Tokyo, for what felt like minutes on end. Numerous items fell of shelves, most of my wine glasses are now a pile of shards — and this is several hours by car away from the centre of the quake. We’ve had countless aftershocks for several hours now.

I was alone at home when it happened and have not been able to make mobile phone calls or send SMS to reach my other family members, though my wife and I could communicate by Skype chat (she has an iPhone). I know all the trains are stopped right now, with people walking for kilometers to get home on foot, as did my wife.

The images of tsunami devastation near Sendai are shocking. A refinery is on fire in Chiba prefecture near Tokyo. I wonder how many people will have lost their lives in the tsunami and in collapsed buildings.

UPDATE (2011-03-12 05:38 JST):

All members of my family got home OK. We were watching TV news until 01:30 in the morning. I got many emails, phone calls and Skype chats from concerned friends and relatives.

Several mentioned the serious technical problems in the Fukushima Daiichi nuclear power station. While the government announced an evacuation of people living within 3 km of the station, few details of what was going on were provided. From US and German media reports I hear that both mains power and backup generators are out and that the cooling system seems to have a leak. Tokyo Electric Power Corporation (TEPCO) was trying to connect external power generators. There was talk about releasing steam that had built up to 50% more pressure than the reactor was designed for. Without adequate cooling the reactor core could melt even when shut down due to nuclear decay heat that continues at about 7% of regular power output when the reactor is shut down. The backup diesel generators were not working due to flooding by the tsunami.

UPDATE (2011-03-12 15:20 JST):

The decision to vent the containment vessel of unit 1 of Fukushima Daiichi suggests that efforts to get the main cooling system back online have not been successful, as it reflects excess temperatures of cooling water and heat buildup.

The Tokyo Electric Power Company (TEPCO) has announced it will “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.”

The Reactor Core Isolation Cooling System is a mechanical system to pump cold water to cool the reactor core using a steam turbine driven by boiling coolant water. It does not rely on outside A/C power for the pumps, but needs at least battery power to open and close valves. It is the last line of defense should both grid power and backup power be lost. Without the above mentioned water injection, water levels could fall in the reactor core and the fuel elements could overheat and partially melt, as in the Three Mile Island accident near Harrisburg, Pennsylvania in 1979.

See also:

UPDATE (2011-03-12 22:20 JST):

The cabinet secretary said that the explosion at Fukushima Daiichi #1 power station was a hydrogen explosion. When they released excessive pressure from inside the containment vessel, it contained hydrogen, which mixed with air in between the exterior wall and the containment vessel, and ignited. That blew away the outside wall. Four workers were injured and have been hospitalized.

The hydrogen is assumed to be the result of a reaction between steam and overheated zirconium cladding of the fuel rods. The water level in the reactor must have dropped so far that the top of the rods was no longer immersed in water and became red hot. The zirconium stripped oxygen from water (H2O) which releases hydrogen. If you remember the Three Mile Island accident in 1979, that was the same way the hydrogen bubble was produced in the TMI incident. The fuel rods then melted into a blob, but the restored cooling managed to contain the molten fuel inside the reactor core.

Since all attempts to restart the cooling pumps have failed, the reactor operators are now planning to pump sea water into the reactor vessel to cool the pressure vessel inside. The choice of sea water appears to be dictated by a lack of fresh water on site. Normally one would avoid salt water because of its corrosive effects, but the operators realize that this 40 year old reactor will never be repaired or put back into service again. It’s a wreck and they do all they can to stop its spent fuel from being melted and released.

An area of about 160 square kilometers that lies within 20 km of Fukushima Daiichi or 10 km within Fukushima Daini along the Pacific coast is going to be evacuated.

Nokia’s suicidal alliance with Microsoft

Much has been written about Nokia’s alliance with Microsoft announced last month. I can understand how Nokia CEO Stephen Elop, an ex-Microsoft employee who until recently was its 7th biggest shareholder, would have made this decision that benefited his former employer, but why did Nokia’s board of directors ever agree to this move?

Under attack from the iPhone and Android, Nokia had to take action, but in my opinion this move is almost the worst possible choice. It will be an unmitigated disaster for Nokia. I am not just thinking of countless development engineers who will undoubtedly be laid off now that Nokia will be buying in Windows Phone 7 (WP7) instead of developing operating system software in-house. No, it’s also a major strategic error for the company as a whole and I’ll explain why.

Nokia used to have a great brand name with consumers. Now Symbian phones have “OBSOLETE!” stamped all over them, but that’s all Nokia will have to sell for at least another year. Who is going to buy those obsolete phones, other than at rock-bottom prices? It will be ugly for Nokia’s cash flow. How on earth does Nokia believe it can still sell 150 million Symbian phones between now and their WP7 models replacing them? They’re dead in the water.

I can’t see that Intel would be pleased about what that all means for their cooperation on MeeGo, if WP7 is the future.

In 2008 Nokia acquired Norwegian company Trolltech, developers of the well-regarded Qt cross-platform application and user interface framework. Licensing to commercial users of Qt will be now be transferred to Digia PLC of Finland. Qt will not be ported to WP7. Only a few months ago Stephen Elop still talked about Qt being the common interface for Symbian and MeeGo. Qt was supposed to be the element that ties together Symbian and MeeGo in the mobile world. With Symbian dead and MeeGo on life support and a categorical “NO!” on Qt on WP7, Qt has no future left on mobile. But what else should one expect from a proprietary software company like Microsoft? They have never been keen on applications being ported from Windows to other operating systems, so they want people to use Microsoft tools only.

Nokia’s name is dirt within their developer community because after the announcement the Symbian ecosystem is dead, whatever Nokia would have us believe. It is also hard to believe that Elop had no plans about WP7 a few months ago, when Nokia still fed developers their Symbian / MeeGo / Qt strategy. Many developers must feel deceived. It will be hard for Nokia to regain their trust.

Several hardware makers had worked closely with Microsoft on the previous generation of its phone platform (Windows Mobile), who are now firmly in the Android camp. For example, HTC built the first Microsoft Windows based smartphone in 2002, but released an Android phone in 2008 and shifted the core of its smartphone business to that platform the following year (my Google Ion phone is made by HTC). Though it also offers some WP7 models, the bulk of its smartphone business is now Android.

With Windows Mobile, Microsoft could not translate its dominance on the desktop into traction in the mobile market, so it dumped Windows Mobile, with no compatible upgrade path to WP7. Developers had to rewrite apps from scratch. These early Windows Mobile supporters learned a lesson with Microsoft that Nokia is yet to learn, the hard way: Microsoft always does what’s good for Microsoft, not for its customers or business partners.

Nokia is betting the company on an unproven challenger that is entering the market behind three bigger established competitors (Google, Apple, RIM). Late last year Microsoft boasted ‘sales’ of 1.5 million WP7 phones over a period six weeks. That sounds significant, but what they actually meant by that were phones stuffed into the sales channel, mostly still sitting on shelves at mobile phone stores and not activated phones ringing in the pockets of retail customers. At the same time Google was activating that many Android phones every five days (every 5 1/2 days in the case of the iPhone).

No matter how much market share Nokia will lose over the next few years, whatever market share is left for Nokia with WP7 will still be a gain for Microsoft. And as long as Microsoft still has a steady cash flow from Windows 7 licenses and Microsoft Office it won’t be wiped out by a lukewarm reception for WP7 in the market, which is more than can be said for Nokia.

So why did Nokia make this risky decision? They must have come to the brutal conclusion that the company could not survive long term while still developing their own mobile OSes. Nokia only saw a choice between either switching to Android or to WP7 (or going under).

With Android they would largely have had to compete on the merits of their hardware, as every other Android OEM offers essentially the same software / marketplace “ecosystem”. Nokia didn’t want to compete on price with Asian manufacturers (which, as an aside, is exactly what they’ll have to do with their dead-end Symbian phones for the next year or more, since there will be little new software developed for them now). So if Nokia couldn’t be the top dog amongst Android makers, they could turn the other way and at least take whatever sweeteners they could get from Microsoft, while cutting back their software R&D costs and cutting jobs to weather the storm.

The biggest problem with that strategy in my opinion is that a few years down the road they’ll probably realize that WP7 was a dead end too. Then they’ll still have to make that switch to Android, but having already lost a few years, their good name and a lot of good staff it will be even harder.