November 2024

Radioactive Contamination Found – Can We Identify It?

Welcome back my fellow radiation nerds! Today we will take a closer look at radioactive contamination inside of my lead pig container and try to identify the isotope behind it.

Lead pigs are lead containers used to store highly radioactive sources and shield their radiation to help minimise exposure. This one in particular originally came from one of the German nuclear power plants and it is made out of solid lead and weighs about 2kg. Although the container did not come with any radioactive sources, after unboxing the package, I noticed that the inside of the container emitted radioactivity and was most likely contaminated with some mysterious radioactive source.

This discovery was very exciting and I was very curious to find out what isotope was behind the contamination.

What are we dealing here with?

There plenty of different radioactive isotopes out there, some are natural such as Uranium and Thorium and their decay products, and some are man-made produced in nuclear reactors, in particle accelerators or during atomic tests.

In order to find out what isotope is behind the contamination, I need to narrow down my search and eliminate any isotopes that don’t match the characteristics and properties of the one inside the lead pig.

I’ll start by checking what type of radiation is being emitted from the container. First, I’m going take a measurement first without any shielding and then I’ll start introducing different materials to block out different types of radiation and compare the results. For this purpose I will use my Ludlum Model 3 with a 44-9 probe as it can easily detect alpha, beta and gamma radiation.

  • Alpha particles can travel in air up to 5cm and can be easily stopped with a thicker piece of paper.
  • Beta particles can travel up to half a meter in air and can go through low density materials but a piece of aluminium should be enough to block them.
  • Gamma rays can travel very long distances and are the hardest to shield requiring very dense materials such as Lead or sometimes even Uranium.

From my first measurement without any shielding and I got a result of about 1000 CPM at 1cm distance from the lead pig. After placing a piece of paper between the probe and the container, the result remained unchanged. This meant that there are pretty much no alphas being emitted by the source.

Next, I’ve added a piece of aluminium and the readings dropped significantly, all the way back to background levels meaning that the source was a primarily a beta emitter and even if there was some gamma radiation, it was extremely low and not detectable by my meter.

Gamma Spectroscopy

Although I haven’t detected any gamma radiation above background levels, I still decided to do a gamma spectroscopy with my RAYSID. Sometimes even trace amounts of gamma radiation are enough to build a good spectrum and identify different isotopes.

Inside my lead castle, the background activity is only 1.2 CPS when measured with my RAYSID. After placing the lead pig container inside, I got reading of 3.5 CPS and after collecting data for few hours, I managed to create a gamma spectrum of the lead pig.

The gamma spectroscopy revealed peaks that are characteristic for Uranium ore. I spoke with the previous owner and he did mention that he stored uranium ore inside so definitely there is a chance that a small piece broke off the mineral and is at the bottom of the container, however the amount of beta radiation compared to gamma could hint at another contaminant but unfortunately I don’t have the tools to properly check or identify it.

Conclusion

This is actually not the first time that I see a contaminated lab equipment. A friend of mine has a lead pig that is contaminated with radioactive Cs-137 as a result of a chemical spill inside of it.

I want to hear from you, did you ever find some contaminated lab gear and do you think the remains of Uranium ore are the only contamination inside of my lead pig or could there be some other radioactive isotope. I’m looking forward to hearing your suggestions and answers in the comments below.

Thank you so much for reading this post, I hope you enjoyed it and learned something new! If yes, please make sure to subscribe to the email list so that you get notified when new posts are added. Also feel free to check out my Ko-Fi page where you can donate a nice cup of radioactive coffee and support my work financially.

and remember, stay active!

By allRadioactive, ago

Is the Better Geiger S-2 actually better?

Welcome back my fellow radiation nerds, Today we are taking a closer look at the BetterGeiger S-2 meter and if it’s really a better geiger counter!

Geiger counters are one of the most common tools for measuring the radiation around us, but they’re not perfect. They often suffer from limitations such as inaccurate dose rates and low sensitivity which are a characteristic of the Geiger-Muller tube used by the most meters.

In the recent years, there has been a surge in products that use small scintillation crystals instead of the more traditional GM tubes but they are usually more advance devices, target at experienced users, not entry level amateurs

This is where the BetterGeiger S-2 meters comes in

BetterGeiger S-2

First things first, I would like to thank Robert from Better Geiger who was kind enough to provide me with the S-2 meter making this video possible.

The Better Geiger S2 is a personal radiation detector manufactured in Colorado, USA. It is made out of high quality plastic which feels solid and durable and for extra protection, the unit is wrapped in a rubber case which should prevent it from any fall damage if it would slip out of hand.

While slightly on the bigger side, it can be operated singlehandedly and navigating through the menus and setting was pretty simple and intuitive.

Despite its name, Better Geiger does not use a geiger muller tube. Instead it has a small scintillation crystal which gives about 100 CPM of background activity and is rated for a maximum dose rate of 100 mSv/h for Cs-137.

Unlike most geiger counters, BetterGeiger factors in the different gamma energies detected to give accurate gamma dose readings. The measurements can be displayed as uSv/h, mRem/h or CPM and the unit does also has an alarm feature which threshold can be adjusted to the user’s preference.

While it can detect some strong betas, it’s not particularly sensitive to them and I think it’s better to think of the meter as gamma only.

When compared to my other meters, the BetterGeiger showed much higher sensitivity to gamma radiation which is particularly helpful when looking for radioactive minerals. I got a few uranium hunting trips planned, and I’m very excited to take the meter with me and see how it performs.

Improvements for the future BetterGeiger S-3

I really did enjoy using the BetterGeiger S-2 meter, however I see some potential improvements for future versions to make it even better.

The firstly, I would love to see a bigger sensor which would increase the sensitivity of the meter.

Secondly, I would move the sensor to the top of the meter. At the moment it is facing the user, making it hard and impractical to measure different sources, as it’s not always easy to see the readings on the screen.

Thirdly, I would like to see an improved algorithm which would quickly adjust the readings when there is a sudden increase in activity but then stabilises once the correct measurement is reached. The one currently used is definitely not bad and does the job well but it would make the unit faster and more responsive.

Lastly, the plastic used over the display screen is way too soft which makes it very easy to scratch. I would to see it replaced with a harder one that is more resistant to wear and tear of everyday use.

So, is it worth it?

Considering that the unit is priced at just under 150 dollars, I think it is a good alternative to many other meters in the same price range. I love that it shows accurate gamma dose readings and that it has a higher sensitivity to gamma radiation than a conventional geiger counter. While it isn’t the perfect tool for everyone, as it doesn’t detect beta radiation very well, I think it’s still solid meter offering something new and unique to the market.

I want to hear from you. What are your thought about Better Geiger S-2 and do you have any experience in with it? Let me know in the comments below!

Thank you so much for reading this post, I hope you enjoyed it and learned something new! If yes, please make sure to subscribe to the email list so that you get notified when new posts are added. Also feel free to check out my Ko-Fi page where you can donate a nice cup of radioactive coffee and support my work financially.

and remember, stay active!

Youtube Video

By allRadioactive, ago