Is Radioactivity from Fukushima a Problem for the US? Eric B. Norman. Department of Nuclear Engineering

Transcription

1 Is Radioactivity from Fukushima a Problem for the US? Eric B. Norman Department of Nuclear Engineering

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3 In studies of natural radioactivity, Ernest Rutherford determined there were 3 kinds of radioactivity:

4 Nuclear Reactions

5 Banana Equivalent Dose The element potassium has a long-lived naturally occurring radioactive isotope 40 K An average banana contains ~ ½ gram of potassium 15 Bq/banana where 1 Bq = 1 decay/second Average human contains about 175 gm potassium 5400 Bq from 40 K decays

6 Average Total Dose = 620 mrem = 6.2 msv Results of study by National Council on Radiation Protection in 2010

7 Measurements made in May, picocurie = decays/second

8 March 11, 2011 It's like deja-vu, all over again. Yogi Berra

9 (a) A portion of the gamma-ray spectrum observed from counting 1 liter of rainwater collected in Oakland on March 18 (b) The same region of the spectrum collected from counting a 1-liter sample of Berkeley tap water. Both spectra represent the same counting period of 24 hours.

10 Maximum concentration of 131 I observed in SF rainwater = 16 Bq/liter = 430 pci/liter EPA limit for drinking water = 0.11 Bq/liter = 3 pci/liter Drinking water with the EPA limit of 131 I contamination for 1 year would produce a dose to the thyroid of 4 millirem (0.04 msv). 1 Bq = 1 decay/second

11 4/16/

12 March 2011

13 2011

14 Gamma-ray spectrum taken on the UC Berkeley campus in 2011 showing evidence of Fukushima fallout.

15 Fukushima nuclear fallout Are infants born on the US West Coast and Hawaii in danger? Jul 22, 2013 Fukushima is here, it is no longer a Japanese problem - it is a growing world problem which is still being ignored. A new study in April of 2013 suggested that nuclear fallout from Fukushima in March of 2011 has led to significant elevated rates of congenital thyroid illness among infants born on the West Coast and Hawaii - keeping in mind that President Obama not only denied this threat but ordered the EPA to stop weekly & monthly testing for radiation in April of Study: Fukushima Fallout Affected Hawaii Babies civilbeat: Babies born in Hawaii in the wake of the Fukushima meltdown were more likely to suffer from a developmental disorder than babies born the previous year, according to a recent study. Nuclear isotopes wafting over the Pacific Ocean from the crippled reactors appear to have caused far-reaching health risks that we are only beginning to understand. Hawaii trips are suicide, because of radiation levels. US Death Rates Increase from Fukishima Fallout

16 Fukushima Now Radiating Everyone: Unspeakable Reality FULL ARTICLE ON om/study-fukushimaradiation-has-alreadykilled americans/ washingtonsblog.co m May 22, 2013 Already 14,000 U.S. Deaths From Fukushima?

17 Fish Samples

18 1 pound of tuna from the Philippines Counted for 2 days 137 Cs 662 ~ 0.2 Bq/kg Natural Background

19 Food Samples Recently Analyzed Local red snapper Local squid Local organic yogurt Hawaiian Swordfish Fiji Tuna Alaskan cod Alaskan salmon 137 Cs < 0.5 Bq/kg 40 K ~ 200 Bq/kg

20 US Food & Drug Administration Limits for Radioactivity in Food Several samples of foods we tested have fallout (NOT from Fukushima) present, but at levels BELOW (1/2000)th of FDA limit

21 Bladderwrack Seaweed from Oregon 40 K 1461

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23 Table 1. Results of gamma counting Naturespirit Herbs LLC seaweed samples. Sample Name Collection Date 137 Cs Activity 40 K Activity Bq/kg Bq/kg Kombu July 25, Wakame July 11, Kelp Fronds June 12, Gigartina July 26, Bladderwrack July 9, Note: 1 Bq = 1 disintegration/second FDA Derived Intervention Level for 134 Cs Cs = 1200 Bq/kg in food

24 (a) 134 Cs Cs Cs 795 Oakland Weeds (b ) Local Organic Milk Sample 1

25 Table 1. Results of gamma counting local organic milk samples. Sample Number Sell by Date Cs Activity 40 K Activity 1 March 4 < Bq/liter Bq/liter 2 March 4 < Bq/liter Bq/liter 3 February 26 < Bq/liter Bq/liter 4 March 3 < Bq/liter Bq/liter

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27 Conclusions We see no evidence of radioactivity from Fukushima in any of the food samples tested. This statement is based on the fact that we do not observe any 134 Cs activity. Extremely low levels of 137 Cs were observed in most of the fish and seaweed samples. The presence of this radionuclide is probably due to atmospheric nuclear weapons tests done in the 1950 s and 1960 s. The level of 137 Cs observed in the seaweed and fish samples is at most 1/2000 of the US FDA derived interventional level for 134 Cs Cs in food products. The major radionuclide observed in the seaweed and fish is the naturally occurring isotope, 40 K. The levels we observe indicate that the dried seaweed samples contain 1.5% - 12% potassium by mass. Radioactivity from Fukushima is not and will not be a problem for the US.