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0 pointsmrschwabe10y ago0 comments

In an attempt to grasp how toxic the water is, wouldn't it be more effective to measure levels of cesium 137 instead of overall background radiation? I don't care what background radiation the entire Pacific has, I care if the sushi I'm eating has ionized, cancer-causing particles in it.

"Michio Aoyama’s initial findings were more startling than most. As a senior scientist at the Japanese government’s Meteorological Research Institute, he said levels of radioactive cesium 137 in the surface water of the Pacific Ocean could be 10,000 times as high as contamination after Chernobyl..."

http://www.nytimes.com/2014/03/17/world/asia/concerns-over-m...

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tptacek10y ago

Your analysis might confuse two different phenomena.

When you mention TEPCO pouring "400 million gallons" into the Pacific, what you're talking about is them dumping contaminated cooling water from tanks into the ocean. The scale of that dumping is caused by (a) the ongoing need to pump water into the compromised reactor to cool it and (b) the large amounts of water they've already stored. However: that water is also filtered, to remove the (actually dangerous) Sr-90. What's being dumped into the ocean is HTO, not Sr-90 or Cs-137.

On the other hand, the meltdown at Fukushima contaminated the entire area with Cs-137, most of which is in the soil, sediment, and sand. The Cs-137 contamination is much worse than the HTO contamination. However, it is also not ongoing; in fact, increase in cesium detected around the plant has fallen dramatically in the last two years.

mrschwabeOP10y ago

Fair enough - though I'm not sure if I will just take your word for it that the potential for new releases of new cesium 137 is not an ongoing threat from Fukushima Daiichi. The only way we can know for sure I suppose, is through the efforts of independent researchers brave enough to get close to the facility.

In the spirit of HN, it would be neat to see an open technology solution for the purposes of monitoring. Ie:

  if(waterSample.cesium137 > 0.001) return ALARM(waterSample)

gh02t10y ago

> it would be neat to see an open technology solution for the purposes of monitoring

It's trivial to do so. Decay of Cs-137 releases a 662 keV gamma ray that is easily measured and the count rate is proportional to the source activity (or ultimately the total amount of Cs-137 present). You can calibrate an inexpensive NaI detector such that it will tell you how much Cs-137 is in a given volume of water. If you place it next to a pipe that has a constant flow rate, you can infer the average amount of Cs-137 in the liquid flowing through the pipe. It's something that you can build in an afternoon if you know what you're doing and have the equipment.

This is pretty much how they monitor liquids for contamination in a real plant, except they use more detailed spectral measurements to monitor multiple isotopes. If you ever have the rare opportunity to go into a reactor control room, there will be a display somewhere that reads out this exact measurement.

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