Wednesday 20 June 2012


Hi all,
Interesting programme on NHK last Sunday (10 June). I guess a follow up to the one about the sea in January (see The Sea), this time about the effects of the nuclear accident on rivers.

There are two main rivers flowing out of Fukushima. The Abukuma River which flows through Koriyama and Fukushima and into the Pacific in neighbouring Miyagi prefecture, south of Sendai. Then the Agano River, the confluence of many tributaries collecting rain and snow melt from Mount Bandai and south Aizu, which flows into the Japan Sea in Niigata prefecture.

Tests show that the water is clean. So drinking water is safe. The problem is in the muddy deposits on the river bed. It turns out there are two kinds of 'hotspots'. First, caesium has been dumped along with sand where tributaries meet the main river. The other main deposits are at the mouth of the rivers but in this case caesium has bonded with vermiculite in the clay and has been carried long distances before settling.

The mystery of high radiation in Ikenodai, a top residential area of Koriyama, is solved. Though radiation in the air in most of Koriyama is about 0.5 μSv/hr, there it sticks stubbornly at 1.9. It turns out that the two ponds there, Sakubuta Pond and Arai Pond are situated where some small rivers meet and became a dumping ground for caesium. Sakubuta Pond has been drained of water for some reason (I can't find out why) and according to an expert on the programme (Kimura-sensei who I've mentioned before) the pond is beaming out radiation and the only way to reduce levels is to scrape up all the mud and put it into sealed concrete containers in the middle of the pond.

Similarly the rivers in Aizu Bange are another 'hotspot'. The Aizu area itself has very low radiation, but Bange is situated where many small rivers come together.

Problems too for the people at the mouth of these two rivers far away from Fukushima. Fish poke about in the mud, eat little worms and things and get contaminated. So these poor people, who thought they were spared the agonies of Fukushima, find that they have to do the same as producers here: test, test, test.

On a brighter note, fishing has re-started in Soma on the Pacific Coast for three kinds of fish. Well, not fish exactly: one kind of octopus and two kinds of shellfish. But it's a start and again with lots of testing, maybe people can start to get back their living.
We're in the middle of a typhoon. Very unusual for June. Heavy rain and winds. Due to hit here early tomorrow morning. Poor people in Ishimaki and other disaster areas evacuated yet again.

No comments:

Post a Comment