Fukushima: Highly Radioactive Sewer Sludge [???]
May 15th, 2011Wha?? How?? I… *mumble* *sputter*
What is happening here? Is this from fallout coming down in rainwater and then getting into the sewage infrastructure?
Via: Mainichi:
Highly radioactive sludge found at sewage plants in Fukushima Prefecture will be temporarily kept at those plants, the central government has announced.
The move came after high levels of radioactive cesium were detected in sludge and other waste material at sewage plants in Fukushima Prefecture — home to the disaster-crippled Fukushima No. 1 Nuclear Power Plant.
On May 12, the government announced that highly radioactive sludge will be tentatively kept at sewage plants in the prefecture, while sludge with relatively low-level radiation could be recycled into cement and other material.
While highly-radioactive sludge will be treated in the same way as radioactive waste for the time being, no plans for the final disposal of such sludge were presented. It will also be difficult to promote the recycling of sludge with high-level radiation contamination. Since relevant laws and regulations do not cover highly-radioactive sludge at sewage plants, the government faces serious challenges in handling the issue.
According to the announcement, sludge with radioactivity levels of over 100,000 becquerels per kilogram should preferably be incinerated and melted in Fukushima Prefecture before being kept at sewage plants. Ash generated through sludge incineration should be contained in metal barrels to prevent it from scattering. Sludge with radioactivity levels of under 100,000 becquerels per kilogram can be temporarily kept at sewage plants and controlled disposal sites, with radioactivity monitoring required.
“Radioactive sludge should be treated in the same way as radioactive waste,” said an official with the Cabinet Office’s Nuclear Disaster Countermeasures Headquarters, adding, “We will look into how to ultimately dispose of it later.”
The sewage contamination is almost certainly coming from groundwater. Groundwater infiltrating into sewage after an earthquake is an established phenomenon.
Or they pumped some of the coolant water into a drain either by accident or on purpose.
http://search.japantimes.co.jp/cgi-bin/nn20110514a2.html
this comically vague article yesterday carried by the Kyodo News wire service gives us a few things to chew on (?!?)
1. the radioactive ash and sludge thing is NOT limited to Fukushima.
2. my guess on possible explanations/interpretations: after the explosions in mid-March, there was some serious stuff drifting around which eventually came down with the rain. it entered municipal water supplies. it also entered rainwater runoff systems. so, what has ended up in the sewage treatment plant sludge and incinerator ash has two probable sources in my opinion: rainwater runoff; and excretions from humans. aparantly most cesium is excreted as part of the body’s homeostasis.
3. the big questions are: what percentage of this stuff has come from human excretion; and can we get rid of the radioactive cesium from our bodies by ingesting normal cesium?
sorry, forgot to close the bold tag…
The sewage infrastructure was cracked, damaged after the earthquake. Large amounts of water might be moving in from Fukushima run off and wider Fukushima related rain.
Then the sewage treatment would lift it out with all the other trapped solid material as normal.
runoff from Fukushima doesn’t reach Tokyo. it’s over 200 km away. and rivers near Tokyo are not fed from Fukushima either. airborne particles from the explosions in mid-March came down in the rain. it was in the water supply and in some foods. most of the treated sewage sludge that they incinerate is not coming from rain runoff. it’s from human waste and gray water.
@tochigi
I can’t find any follow up to this one. Did you see anything else in Japanese language sources?
funny you should ask, because i was scratching around in google news last night (Japanese version) trying to get some better info. i haven’t found much. there are lots of reports about the radioactive sludge and ash, but most of them are discussing the controversy of what to do with the stuff. normally municipal govts. sell this stuff (ash) to the private sector for use in bicks and cement. there is no precedent for this problem so no one wants to take responsibility (sound familiar?). anyway, so far i cannot find much explanation of how it got into the sewage treatment plants except “rainwater.” anyway i will keep looking and let you know.