Measurements of Radioactivity in Local Park

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Measurements of Radioactivity in Local Park

I took a journey today down to my local park in Fredericksburg Virginia in order to test the ambient radioactivity in the soil, plants, and streams. Alum Spring Park has been a favorite place of mine since I was a child and today was no different. The trees were in bloom, pink and white, and the ground covered in little blue flowers. Children played, people talked, and suddenly, a man with crazy long hair and a Geiger Counter arrived…

I walked around the park and looked for good places to test. Here are the results of my tests including pictures and locations. I took samples and performed spot testing. I returned to the lab for more detailed testing.

April 17, 2011 Test of Alum Spring Park:

tom at work

tom at work

1:51 PM – Took 5 min ambient air test. I always avoid sunlight and allow air to rush over my thin-ended mica window on my Geiger Counter. I received 69 counts in 5 minutes, which equals 13.8 CPM at 1 meter above the water by the stream.

park

Air tests at part


2:00 PM – Took 2 min rapid count of air just before testing of wet plants. 25 counts in 2 minutes which equals 12.5 CPM

2:05 PM – Took 2 minute rapid test of wet grasses growing in the water. They would probably contain radionuclide’s in their vacuals if they in-took them. The plants were wet and held about 1 foot above the water as I tested them. They produced 28 counts in 2 minutes which results in 14 CPM.

grass

grass


2:16 PM – Tested air by water and clay deposits for 5 minutes to establish baseline. 88 Counts were found in 5 minutes resulting in 17.6 CPM baseline.

2:23 PM – I placed the Geiger Counter within a bag to prevent water from spilling and exposed the sidewall and thin mica window to the water at 2.5 cm distance. I counted 98 counts in 5 minutes, averaging 19.6 CPM.

clay

clay


2:40 PM – Performed 5 minute baseline on a log to check average. 5 minutes produced 74 CPM which equals 14.8 CPM
baseline

baseline


2:50 PM – Took 3 minute rapid count on table for baseline before testing plants. 3 Minutes found 43 counts which equals 14.33 CPM.

2:55 PM – tested White Dogwood Tree flowers for 5 minutes and found 70 counts, which equals 14 CPM.

dogwood

dogwood

Summary
In summary, only the water samples tested in the stream showed any noticeable change over background. When I tested the water in the lab I found little change. This has to do with me current problem of not being able to test liquids very well. I am working on finding better ways to test liquids, other than holding my hand, which does work, over the liquid with the tool.

The Water tested 19.6 vs the ambient 17.6. The difference is 2 CPM. 19.6/10 = 1.96 (The Geiger Count has a +/- 10% accuracy). Subtracting the maximum inaccuracy from the remainder leaves: 2-1.96 = 0.04 CPM above normal.

Currently, this is too close to call!!! I am going to dry the water and measure the sediment for contamination, in lieu of a more powerful instrument.

As best as I can tell, Alum Spring Park is quite safe, currently.