The Japanese Press routinely reports on sudden increases in wastewater radioactivity at F. Daiichi. However, they fail to report on what is going right. Tepco has posted a small mountain of wastewater and atmospheric radiation data since early in 2012. (1) One person has written and said it’s all “gibberish” because there is so much of it. It takes someone with a radio-chemistry background, and a considerable amount of patience, to sort it all out. From time to time, I try to do just that for everyone.
One wastewater topic I follow concerns the radioactive concentrations in the four turbine building basements at F. Daiichi of most concern (units 1-4). Un-reported by the Press is the fact that the levels of Cs-134, Cs-137, and Beta radiation emitters in the basements is steadily dropping for more than a year. While it is a slow process, it seems that Tepco’s effort to lower these concentrations is working. Here’s a data breakdown (with specific page links)…
A. Units #1 & #2 –
May 22, 2013… … http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2013/images/tb_water_130531-e.pdf (Beta activity was not posted until November of 2013) –
unit #1 – Cs-134 at 1,700 Bq/ml, Cs-137 at 3,700 Bq/ml
unit #2 – Cs-134 at 17,000 Bq/ml, Cs-137 at 36,000 Bq/ml
January 15, 2014… http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2014/images/tb_water_140124-e.pdf (this is the most recent posting by Tepco I can find) –
unit #1 – Cs-134 at 1,000 Bq/ml, Cs-137 at 2,700 Bq/ml, and Beta at 3,900 Bq/ml
unit #2 – Cs-134 at 6,800 Bq/ml, Cs-137 at 17,000 Bq/ml, and Beta at 69,000 Bq/ml
B. Units 3 & 4 –
Unit #3 – Cs-134 at 7,500 Bq/ml, Cs-137 at 19,000 Bq/ml, and Beta activity at 58,000 Bq/ml
Unit #4 – Cs-134 at 1,900 Bq/ml, Cs-137 at 4,500 Bq/ml, and Beta at 9,200 Bq/ml
Unit #3 – Cs-134 at 6,100 Bq/ml, Cs-137 at 20,000 Bq/ml, and Beta at 40,000 Bq/ml
Unit #4 – Cs-134 at 120 Bq/ml, Cs-137 at 360 Bq/ml, and Beta at 590 Bq/ml
For the 8 month period depicted for units 1&2; the unit #1 levels have dropped over 40% for Cs-134 and 27% for Cs-137. For unit #2, Cs-134 dropped 54% and Cs-137 by 53%. For the 8 month period relative to units 3&4; unit #3’s Cs-134 diminished by about 25% and Beta activity by 45% The numbers with unit #4 are literally eye-popping; Cs-134 activity dropped nearly 94%, Cs-137 by 92%, and Beta activity by more than 94%! Of course, unit #4 did not have a meltdown and does not need to cool the damaged fuel (or corium) we have in the other three units. Regardless, all decreases are much greater than can be attributed to radioactive decay. Tepco should be commended for their wastewater decontamination effort.
Does this equate to a significant success story? Without a doubt! Does the Japanese Press consider it newsworthy? I guess not.
1- the Tepco radiological data and archives are entitled Handouts at Press Conference can be found here… http://www.tepco.co.jp/en/nu/fukushima-np/handouts/index-e.html