The debate on the amount of fuel remaining.

Fig. 12: Changing wind conditions after the accident spread radioactive clouds across the whole of Europe. The path taken by the clouds can be followed by clicking on the map. UNSCEAR Report, New York 2000, Annex J. Fig. 13: Local map of radioactive contamination around Dobrush, east of the regional capital Gomel, showing a patchwork of severely or mildly contaminated areas. Dobrush District, 2002. (Please click to enlarge) Fig. 11: The radioactive contamination caused by the Chernobyl accident will continue to place a burden on the environment in Belarus, Russia and Ukraine for many decades to come. Some of the radioactive elements have a half-life of several thousand years. © Chernobyl Interinform Sources (3.12)  Wolfgang Botsch: Untersuchungen zur Strahlenexposition von Einwohnern kontaminierter Ortschaften der nördlichen Ukraine, Universität Hannover, 2000, p. 13 (5.3)  Sahm, Astrid: Transformation im Schatten von Tschernobyl, Münster, 1999, p. 185 (8.3)  Chernobyl Interinform Agency: Kiew, Interview on 18.04.2002, p. 7 (24.1)  Strahlentelex 362-363/2002, Inhaltsangabe des Films: Tschernobyl - Der Millionensarg, ZDF, Mainz, März 2002, p. 2 Further literature (102)  Checherov K.P., Kumshaev S.B., Torkarchuk M.V.: Scale of radionuclide emission at the Chernobyl Nuclear Power Plant in 1986 (The analysis of estimations), Condensed Matter Physics, Vol. 3, No. 3, 2000 Glossary Becquerel (Bq) Caesium/Caesium-137 Curie (Ci) Iodine Sievert Strontium Plutonium Half-life Radiation and radioactivity Further information Sarcophagus and closure

How much fuel was released?
During the maximum credible accident at the Chernobyl nuclear power station on 26 April 1986, an estimated 50 to 250 million Ci of radiation was released (5.3; 8.3). Many publications compare the accident with the atom bombs dropped on Hiroshima and Nagasaki. In Chernobyl the destructive potential of at least one hundred atom bombs was unleashed. So far, the majority of experts have assumed that the explosion released only part of the reactor fuel. Most estimates give the amount as between 3.8 and 20 per cent. At the time of the accident there were 200 tonnes of uranium in the reactor (3.12).

These figures may have to be revised upwards. In early 2002 the debate took a new turn following research by the Soviet nuclear physicist Konstantin Checherov of the Kurchatov Institute in Moscow and his German colleague Sebastian Pflugbeil, Director of the Society for Radiation Protection in Berlin. The two nuclear physicists claimed, in a documentary broadcast on German national television (ZDF), that most of the fuel had been released into the environment, with only an insignificant amount remaining in the reactor itself.

The Ukrainian government agency Chernobyl Interinform, however, contends that studies of the reactor over 15 years indicate that 95 per cent of the fuel still remains within the reactor (8.3). The issue of how much fuel escaped is especially relevant in the light of plans to construct a second protective sarcophagus for the stricken reactor (5.3; 24.1; 8.3).