3 ms·

That is a great paper[1], thanks for the reference I've added it to my nuclear effects library. It doesn't involve the China Syndrome speculation though, what

That is a great paper[1], thanks for the reference I've added it to my nuclear effects library. It doesn't involve the China Syndrome speculation though, what it does find is much much more interesting. The paper reports that beach sand is capable of 99% adsorption of Cs137. And then goes on to discuss how it gets de-adsorbed (up to 11%) when Cs137 free sea water is mixed with it. What this says to me is that you can use really cheap beach sand to filter the discharge water from a nuclear reactor and collect 99% of the Cs137 in the water which will stick to the sand. The sand in your filter can be replaced and the cesium rich sand can be sequestered for the Cs137 to decay over time. This is an excellent finding that suggests reactors have a reservoir of sand for pumping cooling water through especially during reactor compromise. Knowing this a future even would release significantly less Cs into the ocean, collecting it instead in the sand filter. [1] The experiments showed that beach sands have an adequate ion exchange capacity for this level of 137Cs, with an average adsorption fraction of 99% regardless of the salinity, sediment grain size, or mineralogy (Table S3). ---https://www.pnas.org/content/early/2017/09/26/1708659114 https://www.pnas.org/content/early/2017/09/26/1708659114

pvaldes 8y ago
> regardless of the salinity, sediment grain size, or mineralogy Yes, I though also about it, but I will add something to the idea of a sand filter. This is not our average dead sand, is marine sand, cleaned and oxigenated constantly by the tides. If we discard an effect of grain size, and sand composition, the really interesting hot-stuff is IMHO probably in what remains, the bacterial biofilm coating the sand.
aldoushuxley001 8y ago
What are you using to organize your nuclear effects library?
firebones 8y ago
What volume of sand would you need to make a difference? And at what rate does it collect Cs137 to reach 99%? Would it be feasible to stack filters? (E.g., 0.01 * 0.01 * 0.01...)
tarre 8y ago
Decontamination factor of 100 is rather terrible compared to DF of over 8 million of actual filter materials, which are being used at Fukushima: https://www.fortum.com/sites/g/files/rkxjap146/files/documents/efficiency_of_fortums_cstreat_and_srtreat_fukushima.pdf https://www.fortum.com/sites/g/files/rkxjap146/files/documen... See also: https://www.fortum.com/products-and-services/power-plant-services/nuclear-services/nuclear-waste-management/nuresr https://www.fortum.com/products-and-services/power-plant-ser...
- adrianN 8y ago
  Adding another factor of 100 with something as cheap as sand still seems worthwhile.
  - tarre 8y ago
    There are reasons, why not to do that: 1) DF doesn't add up like that at low concentrations. Then it comes down to selectivity of the material. Sodium and cesium have similar chemical characteristics, but CsTreat is very efficient in selecting Cs over Na. 2) Material you are using as filter becomes radioactive waste. You want to keep the volume at minimum. 3) With CsTreat you already reach radioactive Cs levels below measurable limit. There is no reason to try to remove more Cs from that water :)
    - pvaldes 8y ago
      Honest question. Is is being CsTreated since eight years, why we do have radioactive Caesium still accumulating in the coast? > 2) Material you are using as filter becomes radioactive waste. You want to keep the volume at minimum. This is very reasonable, but storing sand for 50 years somewhere is technically feasible and maybe even cheaper than storing water. You can put the sand in concrete and obtain a solid block. Then put the package in some kind of coating and bury it in a safe vault. Water instead has the bad habit to leak, run away, and enter in the life chain when bad weather, monsoon or accidents happen. A huge concrete block is also less vulnerable to terrorism than a water tank. Is not so easy to steal a jar of it, for example. Even if you could make a hole in the coating, the product will not just flow out.

pvaldes 8y ago

> regardless of the salinity, sediment grain size, or mineralogy Yes, I though also about it, but I will add something to the idea of a sand filter. This is not our average dead sand, is marine sand, cleaned and oxigenated constantly by the tides. If we discard an effect of grain size, and sand composition, the really interesting hot-stuff is IMHO probably in what remains, the bacterial biofilm coating the sand.

aldoushuxley001 8y ago

What are you using to organize your nuclear effects library?

firebones 8y ago

What volume of sand would you need to make a difference? And at what rate does it collect Cs137 to reach 99%? Would it be feasible to stack filters? (E.g., 0.01 * 0.01 * 0.01...)

tarre 8y ago

Decontamination factor of 100 is rather terrible compared to DF of over 8 million of actual filter materials, which are being used at Fukushima: https://www.fortum.com/sites/g/files/rkxjap146/files/documents/efficiency_of_fortums_cstreat_and_srtreat_fukushima.pdf https://www.fortum.com/sites/g/files/rkxjap146/files/documen... See also: https://www.fortum.com/products-and-services/power-plant-services/nuclear-services/nuclear-waste-management/nuresr https://www.fortum.com/products-and-services/power-plant-ser...

adrianN 8y ago
Adding another factor of 100 with something as cheap as sand still seems worthwhile.
- tarre 8y ago
  There are reasons, why not to do that: 1) DF doesn't add up like that at low concentrations. Then it comes down to selectivity of the material. Sodium and cesium have similar chemical characteristics, but CsTreat is very efficient in selecting Cs over Na. 2) Material you are using as filter becomes radioactive waste. You want to keep the volume at minimum. 3) With CsTreat you already reach radioactive Cs levels below measurable limit. There is no reason to try to remove more Cs from that water :)
  - pvaldes 8y ago
    Honest question. Is is being CsTreated since eight years, why we do have radioactive Caesium still accumulating in the coast? > 2) Material you are using as filter becomes radioactive waste. You want to keep the volume at minimum. This is very reasonable, but storing sand for 50 years somewhere is technically feasible and maybe even cheaper than storing water. You can put the sand in concrete and obtain a solid block. Then put the package in some kind of coating and bury it in a safe vault. Water instead has the bad habit to leak, run away, and enter in the life chain when bad weather, monsoon or accidents happen. A huge concrete block is also less vulnerable to terrorism than a water tank. Is not so easy to steal a jar of it, for example. Even if you could make a hole in the coating, the product will not just flow out.