It seems Tepco will look into any possibility for the reduction of Tritium-laced waters being stored at F. Daiichi in order to dull the pain from the constant socio-political bashing they suffer. However, the latest consideration is nothing more than an exercise in futility… the use of atmospheric evaporation instead of release to the sea.
Hundreds of thousands of tons of water at F. Daiichi have been run through the multistep radionuclide removal process, lowering all concentrations below Tepco’s ridiculously low, self-imposed limits for release…except for Tritium. The Tritium is biologically harmless with the levels found in the Fukushima waste waters, but Tepco is reluctant to do what the rest of the world would do and pump the liquid out to sea. Why? Because any detectible level of radioactivity released to the Pacific exacerbates consumer shunning of Fukushima seafood in Japan’s major markets. Though biologically innocuous, the numbers associated with the concentrations are huge – hundreds of thousands to millions of Becquerels per liter. Big numbers tend to incite panic in the radiophobic demographic, even if below the no observable adverse effect level (NOAEL). All reported concentrations are below NOAEL.
Kurion Corp. is set to provide a Tritium removal technology at F. Daiichi. It will reduce the concentrations by several orders of magnitude, resulting in levels below Japan’s 10,000 Becquerels per liter drinking water limit. However, the process is relatively time consuming and costly. Now, Tepco is considering another couple of options in parallel – evaporation and deep geological burial.
Burial will have its own issues that make it a problem, such as siting the location for it. In all likelihood, public opposition will be considerable, and perhaps impossible to overcome. Thus we might ask… is evaporation a viable, realistic solution?
Evaporation was used to treat waste waters at Three Mile Island. At TMI, about 9,000 tons of contaminated water was evaporated, but it took over two and one-half years! That was about 10 tons per day. More than 300,000 tons of F. Daiichi waste waters have already been fully processed, and another ~250,000 tons await processing. The numbers increase at a rate of about 300 tons per day. The point is that evaporation is a very, very slow process that will not work fast enough to curb the rate of contaminated water production, let alone make the tiniest of dents in the waters currently stored.
In addition, there’s one historical problem that cannot be avoided. Evaporation will release the Tritium into the atmosphere, rather than isolating or eliminating it. Japan’s numerically-significant radiophobic demographic will like this no more than the thought of releasing it to the sea. Former US NRC chairman Dale Klein explains, “They [Tepco] have huge volumes of water so they cannot evaporate it like they did at Three Mile Island.If they did it would likely be evaporated, go out over the ocean, condense and fall back as rainwater. There’s no safety enhancement.” In other words, one way or another, it’s going to end up in the sea, and the radiophobic millions in Japan will not in the least be appeased.
I would quibble one point with Mr. Klein. The Tritium concentrations at F. Daiichi are harmless. How can there be a “safety enhancement” on a process that is already absolutely safe? We’re not dealing with actual safety, in this case. We’re dealing with the perception of safety. I think that Klein means there will be no perceived safety enhancement. Evaporation will release radiation, and phobic fear of radiation is the singular issue.
In my honest opinion, here’s the bottom line on what ought to be done with the waste waters piling up at F. Daiichi. Evaporation will have to surmount the same major socio-political hurdles as unrestricted release of tritiated waters. It will be socio-politically unacceptable because evaporation will make the air (shudder) radioactive and will rain into the ocean when the wind blows out to sea. On the other hand, dilution to below Japan’s standard for release (60,000 Bq/liter), and pumping it out to sea…which can begin immediately, by the way…will result in the same socio-political harangues while providing the quickest, cheapest path to an effective, harmless resolution.
The best way to go seems obvious. The only roadblock is unrealistic, phobic public fear. It seems the fear will never be overcome, at least not soon enough to make a difference in the wastewater situation at F. Daiichi. Sometimes, the best thing to do is not the most popular choice. Tepco, and Tokyo’s NRA, should start diluting and releasing the waters ASAP, and decide to live the radiophobic repercussions.