When I first moved to Berlin, someone told me that there is a radioactive metro station somewhere in the city. Since then, I was on a mission to find it but unfortunately, with little to no success… until recently.
One of the most iconic places in Berlin must be the Brandenburger Tor and only one station away from it is the Potsdamer Platz which is home to the Sony Center as well as The Mall of Berlin, but today, we are going to focus what lies underneath the ground.
A few days ago I was coming back home from work and I had to change trains at the Potsdamer Platz S-Bahn station and as I was waiting for my train, a characteristic orange colour of the tiles caught my eye. From my bag I quickly took out my trusty Terra-P Geiger counter and I brought it near the tiles and within seconds the alarm started screaming.
Interestingly, after measuring a bunch of the orange tiles, I noticed that not all of the them where radioactive. This is most probably because some of those tiles have been replaced with newer ones which do not contain radioactive elements.
A quick gamma spectroscopy of the tiles made with my RAYSID gamma spectrometer, confirmed the presence of uranium. The peak at 186 keV indicates that these tiles contain Uranium-235 which means they were produced using natural uranium and not depleted.
Although these tiles make my Geiger counter scream, they are in fact harmless. That is because they emit mainly alpha and beta radiation and standing just a half meter away from them will result in radiation dropping to normal background levels.
So next time you are going to be visiting Berlin, make sure to bring a Geiger counter with you and check out the Potsdamer Platz S-Bahn station!