With no margin of safety where the I-beam rests, heavy snow or high winds could overload the wall, causing it and the roof of the sarcophagus to collapse. No generally accepted technique for reinforcing the wall has yet been developed. At a conference in Ukraine in December 1994, officials reportedly said that one of the weak points in the structure had been repaired and the sarcophagus could operate for another 10 years. Since 1990, the Ukrainians have used a dust suppresser to periodically spray neutron absorbers inside the central hall, where much of the irradiated debris is located. The Ukrainians reportedly admit that it is difficult for them to determine the stability of the structure using traditional monitoring instruments because some 40 percent of the reactor building within the sarcophagus is inaccessible owing to high radiation levels.
Water poses problems, too.
The leaching by water of radionuclides from the fuel-containing materials is a growing problem, and prevention of groundwater contamination is a high priority. Yet according to a Ukrainian nuclear industry official, the ground-water at the Chernobyl site is being contaminated. According to an official from Germany's GRS, it is unlikely that a large portion of the mass of fuel inside the destroyed reactor would go critical. As particles of this substance are lifted into the air by heat-generated convection currents, the amount of radioactive dust inside the reactor building will increase. Two Ukrainian academicians reported in December 1994 that the possibility of explosion or fire within the sarcophagus is increasing.