Territory contamination with the radionuclides representing the fuel component of Chernobyl fallout

The data obtained through a series of experiments were used to specify the correlation of activities of the fuel component radionuclides of Chernobyl fallout and to create the maps of the 30-krn Chernobyl zone terrestrial density of contamination with Eu-154, Pu-238, Pu239+240 and Am-241 (on 01.01.2000). In the year 2000, total inventories of the fuel component radionuclides in the upper 30-cm, soil layer of the 30-km Chernobyl zone in Ukraine (outside the ChNPP industrial site, excluding the activity located in the radioactive waste storages and in the cooling pond) were estimated as: Sr-90-7.7 x 10(14) Bq; Cs-137-2.8 x 10(15) Bq; Eu-154(-1.4) x 10(13) Bq; Pu-238-7.2 x 10(12) Bq; Pu239+240 1.5 x 10(13) Bq; Am-241-1.8 x 10(13) Bq. These values correspond to 0.4-0.5% of their amounts in the ChNPP unit 4 at the moment of the accident. The current estimate is 3 times lower than the previous widely-cited estimates. Inventories of the fuel component radionuclides were also estimated in other objects within the 30-krn zone and outside it. This allowed more accurate data to be obtained on the magnitude of a relative release of radionuclides in the fuel particles (FP) matrix during the Chernobyl accident outside the ChNPP industrial site. It amounts to 1.5+0.5% of these radionuclides in the reactor, which is 2 times lower than the previous estimates. Two-thirds of the radionuclides release in the FP was deposited on the territory of Ukraine. (C) 2003 Elsevier Science B.V. All rights reserved.