The NATO Semipalatinsk project - an assessment of longterm effects of atomic bomb tests in Kazhakstan on the population

To determine the long-term consequences of atmospheric atomic bomb tests for the population in the surroundings of the former nuclear weapons test site near Semipalatinsk, a pilot study was performed by international cooperation between Kazakh, French, Czech and German institutes at two measuring locations (Mostik, Maisk) in Kazakhstan. Mostik is a village close to Dolon and downwind of the first atomic bomb explosion on August 29, 1949. Maisk is close to Kurchatov and not too far from ground zero. The results show that surface contamination from nuclear weapons tests has in the meantime decayed to a large extent. External doses largely correspond to the natural background. The remaining incorporation of longer-lived radionuclides is also slight and in 1995 for 137Cs and 90Sr merely led to an annual dose of less than 1% of the natural radiation exposure. The question of a dose contribution by the possible incorporation of 239Pu remains open. Dose contributions from intake of uranium seems to be of natural origin. Life in the villages of Maisk and Mostik does not currently involve any radiological threat to the inhabitants. Two scenarios have been investigated to reconstruct the dose accumulated since 1949 due to incorporation of 90Sr. It has been found to be in the order of magnitude from a few mSv up to about 100 mSv. However, dose reconstruction for the older inhabitants directly affected by above ground atomic weapon tests remains difficult and needs further effort. (orig.)