Detection of nuclear weapons tests becomes more precise

The Schauinsland monitoring station of the BfS with the new building containing measuring equipment for monitoring the Comprehensive Nuclear-Test-Ban Treaty.

With a new measuring system, it will be possible to detect clandestine underground nuclear weapons tests even better. At the end of January, the Federal Office for Radiation Protection (BfS) completed the six-month test phase of a new system for measuring radioactive noble gases in the air on behalf of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO).

This should make it possible to detect even lower concentrations than before and thus make the measurements even more precise.

"With the exception of North Korea, no nuclear bombs have been tested anywhere in the world since the international monitoring system was established in the late 1990s. This is a major partial success for the goal of nuclear disarmament. In order to ensure that this remains the case, the control system must be continually developed. By testing of a new measuring system on the Schauinsland, the BfS has made an important contribution to this", says Inge Paulini, president of the BfS, referring to the international importance.

New measuring system on the Schauinsland enables more precise measurements

Detecting clandestine nuclear weapons tests is the task of the CTBTO. Several dozen interconnected, international measuring stations can detect even the slightest traces of radioactivity in the air. Other stations measure seismic signals. The BfS operates the only measuring station in Central Europe that can carry out highly sensitive radioactivity measurements for the CTBTO. The station is located on the Schauinsland near Freiburg.

Measuring the radioactive isotopes of the noble gas xenon is particularly important because this noble gas also enters the atmosphere after underground nuclear weapons tests and can thus be measured. On the Schauinsland, there is already a system for measuring radioactive noble gases. There, air samples are taken daily and analysed with highly sensitive measuring equipment.

Measurement of radioactive noble gases

A new measuring system on the Schauinsland has now been tested. It is to be used in the international measuring network of the CTBTO.

The new system takes samples from the air every six hours – this is four times more frequently than the current system on the Schauinsland. It is also even more sensitive than the old one. This should make it even easier to determine the origin of radioactive substances.

Network for the detection of radioactive air particles and noble gases

Worldwide, 80 stations for monitoring radioactivity in the atmosphere are planned within the framework of the CTBTO. 40 of these should also be able to detect radioactive noble gases. 72 stations are currently in operation; 25 of these also detect radioactive noble gases.

Shortly after the Second World War, researchers from Freiburg began measuring cosmic radiation on the 1,200 metre high Schauinsland near Freiburg. In March 1953, they noticed unusual readings that turned out to be traces of radioactive fallout from an atomic bomb test in the Nevada desert (USA). This was the first time researchers were able to detect radioactive substances from nuclear bomb tests conducted outside of Germany.

The last above-ground nuclear bomb explosion in China in October 1980 was also detected on the Schauinsland. The radioactive cloud that passed over Europe after the reactor accident in Chernobyl in the spring of 1986 as well as the radioactive elements from the accident in Fukushima were also registered on the Schauinsland.