Odd radtioactivity from US-based organic soybeans

[ChrisqMalibu]

Hi all,

I have been making my own organic soy milk using this machine (can also make soup, etc) @ https://tinyurl.com/549ek2e5 I bought my first bag of organic soy beans recently. Today, I decided to take a look using the 2nd unit of GQ GMC-600 Plus. Here is what I got totally unexpected. This organic soy beans is supposed to be grown in the US @ https://tinyurl.com/yw8epfjc

Here is the first measurement @ https://imgpile.com/i/5s2rHG Here is the 2nd @ https://imgpile.com/i/5s2zpa & here is the 3rd @ https://imgpile.com/i/5s2VbX

I even switched to my 1st unit of GQ GMC-600 Plus to see if it will detect anything. Here is the 1st @ https://imgpile.com/i/5s2Xmh , 2nd @ https://imgpile.com/i/5s2zpa and 3rd @ https://imgpile.com/i/5s2qNr There is something for sure. This weekend, I'm going to try to find out what it is.

[Sparky]

You can turn your three 5 min surveys into one 15 min survey by calculating the number of counts (rate X 5 minutes) and summing the results. More counts means greater accuracy. In your first set of three 5 min surveys, you had 964 counts with the beans and 652 counts with background. Using these counts, my spreadsheet says there is 0% chance that the beans are the same as background and a 68% chance that the true rate over background is between 18.1-23.5 cpm. The uSv/hr values don't mean anything because your pancake detector has no energy compensation filter or even a beta filter. Soy beans are a great source of potassium. You are mainly detecting betas from the potassium.

https://ehs.berkeley.edu/sites/default/ ... ectors.pdf

[iRad]

Chris - Please check out your "Private messages" from me and contact me at my email address. Thanks, Tom

[ChrisqMalibu]

You can turn your three 5 min surveys into one 15 min survey by calculating the number of counts (rate X 5 minutes) and summing the results. More counts means greater accuracy. In your first set of three 5 min surveys, you had 964 counts with the beans and 652 counts with background. Using these counts, my spreadsheet says there is 0% chance that the beans are the same as background and a 68% chance that the true rate over background is between 18.1-23.5 cpm. The uSv/hr values don't mean anything because your pancake detector has no energy compensation filter or even a beta filter. Soy beans are a great source of potassium. You are mainly detecting betas from the potassium.

https://ehs.berkeley.edu/sites/default/ ... ectors.pdf

Thanks again, Sparky! I got to read the book!

[ChrisqMalibu]

Chris - Please check out your "Private messages" from me and contact me at my email address. Thanks, Tom

Thanks, Tom. I just emailed you.

[ChrisqMalibu]

I'm using PRA today to try check soy beans but it doesn't let me change the Interval Histogram value from 20.8 to 2.6. I hit Apply & it immediately reverts back to 20.8. I even loaded old setting that worked fine the last time, it also got stuck at 20.8. I restarted laptop, uninstall & manually delete the old PRA folder to reinstall, it is still at 20.8 https://imgpile.com/i/5c9IRr

When I checked against Cs-137 source, it's out of whack https://imgpile.com/i/5c9vGP

Any suggestions what to do next?

[ChrisqMalibu]

You can turn your three 5 min surveys into one 15 min survey by calculating the number of counts (rate X 5 minutes) and summing the results. More counts means greater accuracy. In your first set of three 5 min surveys, you had 964 counts with the beans and 652 counts with background. Using these counts, my spreadsheet says there is 0% chance that the beans are the same as background and a 68% chance that the true rate over background is between 18.1-23.5 cpm. The uSv/hr values don't mean anything because your pancake detector has no energy compensation filter or even a beta filter. Soy beans are a great source of potassium. You are mainly detecting betas from the potassium.

https://ehs.berkeley.edu/sites/default/ ... ectors.pdf

[In Summary: To simplify food/water radioactivity inspection, we'll set up baseline for all food/water sample. This will prevent false positives. Certain food/water may have natural/safe level of radioactivity. We'll have spreadsheets that shares among us which will be published online for public access.

We'll use gamma spectroscopy to verify any samples that radioactivity is not detected by RadiaCode 101, Atom Fast 8850 (soon to add RaysID), GMC-600 Plus and GMC-500 Plus at all. This would make it easy for my relatives who are not familiar with nuclear physics to be able to quickly identify potential contamination such as Po-210 in seafood as mentioned below. 2 groups of my relatives live in southern Thailand, not far from Malaysia. They often have seafood. One of them will have GMC-600 Plus which can detect alpha decay from Po-210 (we'll spend more time with seafood, possibly hours in case of low activity).

"Natural radionuclide of Po210 in the edible seafood affected by coal-fired power plant industry in Kapar coastal area of Malaysia"

..Natural atmospheric Radon gas (Ra-222) could decay into Po-210 making it possible to cause Po-210 contamination even without nuclear accidents! This is known to affect both seafood & tobacco. Tobacco farmers also use fertilizers containing Radium that creates Radon gas, eventually decay into Po-210 & Lead-210 @ https://tinyurl.com/55cxrn9n & https://tinyurl.com/2crtec89 ]

Michael,

Let me know what you think about this? I plan to send several units of GQ GMC-500 Plus (dual GM tubes, one of which is for low radioactivity) and GQ GMC-600 Plus to my families & relatives who lives all over Thailand. There are 6 different locations. I'll send 3 GMC-600 Plus and 3 GMC-500 Plus.

Learning from you, I realize using the Food/Sample function on these units is too simple making it difficult to identify false positives. So I plan to do the following to make it real easy without much training.

1) I'll ask everyone to create a spreadsheet (possibly Google Doc) to record baseline radiation level for each food/water they consume. They would get up to between 0.02 & 0.05 or more uSv/hour (most of the sample won't have any). I'll ask them to record CPS as well. I'll ask them to take 30 mins measurement for background & for the sample & repeat 3 times using different sets of the same sample. I'll ask them to use exactly 1 Kg per sample.

They would know what the normal safe level would be for each food/water sample. Contamination would exceed this level making it much easier to spot. Bananas, soy beans, Brazil nuts would be between 0.02 & 0.05 uSv/hour. They will have detailed records of each sample where/when it's purchased/obtained, brand, quantity, etc.

This would make it easy to spot contamination & reduce false positives. They will also mail 2 sets of smaller samples to both of my brothers (they are at different locations) for them to double check as well.

2) Two of my brothers will have 3 different setups for food inspection. They will be our test labs for anything that is not being detected at all by GMC-600 Plus or GMC-500 Plus by others. Everyone would send smaller samples to them each for detailed gamma spectroscopy inspection. Both of them needs to agree on positive or negative results for each sample.

Here are the 3 checks.

Rapid check: They will use RadiaCode 101 & Atom Fast 8850 for rapid inspection. Anyone who bring or mail food/water to be checked, this would be a quick check because K-40 won't trip the default alert level. If it finds something, food/water would be marked as contaminated. No further tests is needed unless they wanna find out what the contamination is. This would save time & speed up the process.

Quick check: They'll use GMC-600 Plus to set baseline for each samples for future references. Anything that is above the norm would be easy to spot.

Gamma check: This would be the GS + large detector to do gamma spectroscopy. All samples that does not show any radioactivity with rapid & quick check would need to go through gamma check. This would be recorded as parts of the baseline.

[Sparky]

ChrisqMalibu,

I sent you a private message, but it never cleared my Outbox. ?? Please try and send me a private message, and I will reply.

Thanks,

[ChrisqMalibu]

Thanks, Michael! I just replied. I'll keep researching. Got to build good lead shielding. I'll spend a lot more time this weekend.