The detection of radioactive material from a venting underground nuclear explosion

In northern Europe, there are many stations in operation for surveillance of airborne particulate radionuclides at low concentration levels. In August 1987, after a leakage from a Soviet underground nuclear weapons test at Novaya Zemlya, at least five countries could detect the event at their national stations. Observed radionuclide concentrations are reported and isotope ratios and meteorological air parcel trajectories are used to characterise the source. (author)