After a bit over a month in Germany we’re back in Tokyo again. This doesn’t mean I think it’s safe here: Bad things could still happen at Fukushima 1 or elsewhere in Japan. Radioactivity may still be leaking for months from the wrecked nuclear power plant. However we have two kids enrolled at schools in Tokyo whose continued education was at risk if we stayed away longer. Meanwhile unlike up in Fukushima, background radiation levels in Tokyo are supposed to be no higher than in Bavaria, if you trust published figures. As long as no more hydrogen explosions happen, some form cooling is maintained for the reactor cores for the next couple of years and the spent fuel pools get topped up regularly it seems likely that the worst is behind us. The situation at Fukushima 1 will remain severe for a long time, but everywhere else it may stabilize.
There is still a lot of concern about contamination of food from areas closer to the nuclear ruins, or anywhere where rain fell soon after Tepco was forced to vent the uncooled reactors when it couldn’t get cooling pumps restarted. Background radiation spiked on the first weekend, then dropped again around the Kanto area, then picked up again when rains fell during winds from Fukushima around March 21-24. Radiation in rain and dust (in Bq/m2) peaked during those days in the Kanto area:
| Sampling period | Iodine-131 (Bq / m2) | Cesium 137 (Bq / m2) | Remarks | |
|---|---|---|---|---|
| 2011/04/20 9:00 – 2011/04/21 9:00 | 20.4 | 20.8 | Rain | |
| 2011/04/19 9:00 – 2011/04/20 9:00 | Not detectable (ND) | 29.8 | Rain | |
| 2011/04/18 9:00 – 2011/04/19 9:00 | 55.7 | Not detectable (ND) | Rain | |
| 2011/04/17 9:00 – 2011/04/18 9:00 | Not detectable (ND) | 14.8 | ||
| 2011/04/16 9:00 – 2011/04/17 9:00 | Not detectable (ND) | 6.31 | ||
| 2011/04/15 9:00 – 2011/04/16 9:00 | Not detectable (ND) | 4.75 | ||
| 2011/04/14 9:00 – 2011/04/15 9:00 | Not detectable (ND) | Not detectable (ND) | ||
| 2011/04/13 9:00 – 2011/04/14 9:00 | Not detectable (ND) | Not detectable (ND) | ||
| 2011/04/12 9:00 – 2011/04/13 9:00 | Not detectable (ND) | 4.02 | ||
| 2011/04/11 9:00 – 2011/04/12 9:00 | 100 | 169 | Rain | |
| 2011/04/10 9:00 – 2011/04/11 9:00 | 2.99 | 5.18 | ||
| 2011/04/09 9:00 – 2011/04/10 9:00 | 19.4 | 7.9 | Rain | |
| 2011/04/08 9:00 – 2011/04/09 9:00 | 8.9 | 11.7 | ||
| 2011/04/07 9:00 – 2011/04/08 9:00 | 5.25 | Not detectable (ND) | ||
| 2011/04/06 9:00 – 2011/04/07 9:00 | 6.22 | 10.3 | ||
| 2011/04/05 9:00 – 2011/04/06 9:00 | 8.17 | 5.57 | ||
| 2011/04/04 9:00 – 2011/04/05 9:00 | 16.9 | 5.94 | ||
| 2011/04/03 9:00 – 2011/04/04 9:00 | 20 | 17.5 | ||
| 2011/04/02 9:00 – 2011/04/03 9:00 | Not detectable (ND) | 8.03 | ||
| 2011/04/01 9:00 – 2011/04/02 9:00 | Not detectable (ND) | 14.5 | ||
| 2011/03/31 9:00 – 2011/04/01 9:00 | 37.6 | 26.1 | ||
| 2011/03/30 9:00 – 2011/03/31 9:00 | 50.1 | 68.4 | ||
| 2011/03/29 9:00 – 2011/03/30 9:00 | 21.3 | 5.35 | ||
| 2011/03/28 9:00 – 2011/03/29 9:00 | 36.9 | 18.1 | ||
| 2011/03/27 9:00 – 2011/03/28 9:00 | 45.5 | 5.52 | ||
| 2011/03/26 9:00 – 2011/03/27 9:00 | 101 | 35.9 | ||
| 2011/03/25 9:00 – 2011/03/26 9:00 | 217 | 12.2 | ||
| 2011/03/24 9:00 – 2011/03/25 9:00 | 173 | 36.9 | ||
| 2011/03/23 9:00 – 2011/03/24 9:00 | 12 790 | 155 | Rain | |
| 2011/03/22 9:00 – 2011/03/23 9:00 | 35 700 | 335 | Rain | |
| 2011/03/21 9:00 – 2011/03/22 9:00 | 32 300 | 5300 | Rain | |
| 2011/03/20 9:00 – 2011/03/21 9:00 | 2880 | 561 | Rain | |
| 2011/03/19 9:00 – 2011/03/20 9:00 | 39.8 | Not detectable (ND) | ||
| 2011/03/18 9:00 – 2011/03/19 9:00 | 51.4 | Not detectable (ND) |
Until consumers are reassured via broad and thorough testing of food, I think a lot of buyers will avoid food from the whole region (Fukushima and adjacent prefectures), even if radiation in food near or exceeding legal limits was measured mostly inside the evacuation zone (where everybody is forced to leave now) and an area Northwest of it that may also get evacuacted. The government has dragged its feet too much to be able to maintain confidence, for example in Iitate, where both Greenpeace and the IAEA (as unlikely a couple as any) drew attention to radioactive contamination levels warranting evacuation before the government finally asked inhabitants to leave within one month.
Bottled water seems in demand in Tokyo even though, according to the Tokyo water board, caesium-131 and other radioisotopes are below detection levels now.
Nuclear, wind and sockets
Businesses and households are trying as hard as they can to save electricity, after Tepco lost 15 GW of generating capacity, forcing it to impose rolling blackouts. It hopes to restore 5 GW of capacity before the summer by installing gas turbines at existing thermal power plant sites. The situation reminds me of a tongue in cheek advertising slogan used by the nuclear industry in Germany in the 1970s: “Why nuclear power? My electricity comes from the socket!” The nuclear lobby was trying to paint its opponents as ignorant people who had no idea how to secure supplies. It is this arrogant we-know-it-all attitude that has led to disaster and consequently to a disruptive power shortage. “Why alternative energy? My electricity is supplied by Tepco!” is how people were led to think. Millions of sockets in Eastern Japan have been without power because of this, not to speak of tens of thousands evacuated from a nuclear waste land.
Japan has ample potential for geothermal and wind power. It has thousands of km of coastline that could be used for offshore wind farms, yet in 2010 a mere 2.3 GW of wind power was installed, compared to 27.2 GW in Germany. Four of the German states (Sachsen-Anhalt, Mecklenburg-Vorpommern, Schleswig-Holstein, Brandenburg) already get between 47 and 38 percent of their annual electricity production from wind power, far bigger than Tepco’s pre-Fukushima share of nuclear power.
Those junior nuclear engineers
If you thought things were getting back to normal here, think again: In a surprise move, the Japanese Ministry of Education has set a limit of 3.8 microsievert/hour for children in kindergartens, elementary schools and junior high schools. Multiplied by 8 hours a day, 6 days a week for one year it is 10 millisievert per year. This is in fact half the annual limit of radiation exposure that applies to workers in the nuclear industry in Germany, even though children are more sensitive to radiation damage than adults. No, this is not a late April Fool’s joke. Just like nuclear workers, teachers in Fukushima will be issued portable dosimeters to be able to verify that kids stay under the limit. 3.8 microsieverts per hour is about 40 times the current background radiation level in Tokyo. I must admit, that is one of the weirdest developments I have come across in the whole Fukushima disaster so far.
See also:
- Reading of environmental radioactivity level by prefecture
- Offshore windmills weather crisis (Japan Times, 2011-03-12)