Safecasting abandoned uranium mines

[Note from the editors: Safecast volunteer BergiX has uploaded quite a few interesting logs from former uranium mining sites in Germany and elsewhere. In the process of checking with him about some of the surprisingly high readings he posted before approving his uploads, we learned that he is careful, well-informed, and researches sites well before visiting them. We invited him to share his experiences on our blog.]

By BergiX

If you are lucky enough to own a bGeigie Nano and not live near a nuclear disaster zone, you are probably used to seeing a lot of measurements in the range of 0.X µSv/h. Depending on where you live, though, it may not be very difficult to make the alarm LED on your device light up.

As readers probably know, all nuclear fuel ultimately comes from natural deposit sites. Today, most of the uranium for military and civilian use comes from Australia, Canada, Kazakhstan, and various countries on the African continent, where the largest deposits are located. Historically, much smaller deposits, pretty much discovered by accident, have been exploited. The beauty about those historic deposits is that many are more accessible than you might think. A good place to start looking for uranium sites to survey is Wikipedia.

From this list, I chose the uranium mine of Menzenschwand, Near St. Blasien, Black Forest, as my first Safecast exploration project, since it’s reasonably close to where I live. As with most European uranium mines, this exploration site was closed decades ago (1991) and the site was torn down and pretty much left to itself. So unless you have a Geiger counter with you, it might be hard to find the remains of that mine. Luckily, the German Wikipedia page provides GPS coordinates (Google translate link).

So off we go to Krunkelbach Valley.

Panorama of Krunkelbach Valley
Panorama of Krunkelbach Valley

As we approach the valley of Krunkelbach from the village of Menzenschwand, we are presented with a lovely valley, great for hiking and, judging from the steep hills left and right, great for skiing, paragliding and winter sports. We also find the valley used for agricultural purposes, since the path down the valley passes several nice pastures with lots of cattle to greet an amateur explorer and his bGeigie.

At the end of the Krunkelbach valley, hidden in a small forest, we find a few huts scattered around. Those little buildings house the pumps for the radon spa in Menzenschwand, where you can get yourself irradiated by alpha particles – supposedly for improving your health! (A brief survey of health effects of radon exposure here)  

Since radon is a decay product of radium, and radium is found near uranium, we now know that we are onto something here. And after some searching off the established paths we finally find the former mine, now closed and filled with rubble.

Remains of the Krunkelbach mining pit.
Remains of the Krunkelbach mining pit.

At this location our bGeigie is ticking really nervously, showing > 1 µSv/h at 1 meter above the ground. Near the ground, we measure around 9 µSv/h, which is no surprise, since if we look closely, we can find stones with clearly identifiable uranium salts on their surface.

Yellow uranium salts visible on rocks at Krunkelbach.
Yellow uranium salts visible on rocks at Krunkelbach.

Important note: Please make sure to switch your bGeigie to surface mode when taking readings near the ground. Once you are done, allow the bGeigie to “cool down” a few minutes before you switch back to logging mode, otherwise you might compromise the recorded data, which might show too high a reading. [Editor’s note: The bGeigie records a running 60-second total count, updated every five seconds. Waiting 60 seconds before switching from surface mode to logging mode should prevent any high surface counts from being included in the total at 1 meter].

Better yet, leave the bGeigie about one meter off the ground and use a different Geiger counter to take surface readings (I keep a GammaScout handy for this purpose). Be careful with your equipment though: If you get uranium dirt on your gadgets, they will show too high a reading until you clean each and every groove on them, which can be a hassle.

Check out the bGeigie logs made at Krunkelbach Valley here.

After snapping a few more photos we leave the Krunkelbach pit, once again passing the green pastures of the Krunkelbach valley, reflecting about the cows and the locally produced dairy products.

But wait, there is more: Most European countries were keen on using nuclear energy. And since after WWII there was a race for the nuclear bomb, some of them started exploiting their local resources before turning to other less-highly regulated countries, where radioactive contamination could be left on the surface without provoking vocal outcry.

Brittany, the Northwestern region of France, where I spent a vacation once, was the source of at least some of France’s locally mined uranium up to the 1980s, when France turned to Africa to mine resources for their nuclear program.

Finding reliable information on those uranium mines can be tricky, especially if you don’t know the French language. Fortunately, an NGO named CRIIRAD was created as an independent laboratory to improve public knowledge of and protection from ionizing radiation. Sounds familiar? Check out the CRIIRAD English site . There, even if you don’t speak French, you can find documents listing uranium sites in France, and use your Google maps skills to create a nice map for a round trip of Brittany.

Since describing all of my visits in detail would be a little long, I invite you to check out my Safecast uploads, which should give you a nice overview on where to look for surface traces of uranium mines. Feel free to explore the full extent of those “petites zones de désastre” on your own, as you now know where to start. Be advised though: Some of those uranium mines are now on private property. Please do not trespass.

A few sites I visited in France can be viewed on the Safecast TileMap:

France uranium, part one

France uranium, part two

At some of those sites, like the lovely site of Kervrec’h, you can find information about the past exploitation of uranium, but nowhere did I find official warnings about radiation. Especially at Kervrec’h, some warning would be appropriate, since surface levels can be as high as 12 µSv/h.

Some locations, like the one near Le Hinguer, are particularly hard to identify, since nothing remains of the former uranium mine. You might even miss the spot, if you don’t pay close attention to your Geiger Counters.

The landscape at Le Hinguer
The quiet landscape at Le Hinguer

Other sites, like Trou Ar Ru, near the city of Lannion, border on the grotesque: Here you can find a small red-brownish stream, possibly originating from rusting equipment inside long closed mine, trickling right down into the water reserve of the region. A sign a few meters away happily reminds us to protect the water supply, in French and Breton. The immediate area around this stream is quite radioactive, and water is tricky to get a reading from. Whether the local authorities decide to act upon this or whether anything can be done at all remains to be seen.

Contaminated stream at Trou ar ru
Contaminated stream at Trou Ar Ru

Signpost at Trou Ar Ru urging people to take care of the watershed.
Signpost at Trou Ar Ru urging people to protect the watershed.

From this research I learned that abandoned uranium mines can cause high surface contamination, even if the mine was closed decades ago. So it seems to be a good idea to survey those localized hot spots for the Safecast project to get an overview of where those hot spots are, before these abandoned mines are completely forgotten about.

After a hard day in the field, a little snack, served on a naturally radioactive granite plate!
What a nice surprise after a day of hunting down uranium mines: A radioactive plate my dinner came on.

Bergi_X ( is a Safecast Volunteer.