lava materials are silicate glasses with inclusions of other materials within them. The porous lava is brown lava that dropped into water and thus cooled rapidly. It is unclear how long the ceramic form will retard the release of radioactivity. From 1997 to 2002 a series of published papers suggested that the self-irradiation of the lava would convert all 1,200 metric tons into a submicrometer and mobile powder within a few weeks. [ 175 ] But it has been reported that the degradation of the lava is likely to be a slow and gradual process rather than sudden and rapid. [ 176 ] The same paper states that the loss of uranium from the wrecked reactor is only 10 kg (22 lb) per year; this low rate of uranium leaching suggests that the lava is resisting its environment. [ 176 ] The paper also states that when the shelter is improved, the leaching rate of the lava will decrease. [ 176 ] Some of the surfaces of the lava flows have started to show new uranium minerals such as Na 4 (UO 2 )(CO 3 ) 3 and uranyl carbonate . However, the level of radioactivity is such that during 100 years, the lava's self irradiation ( 2 × 10 16 α decays per gram and 2 to 5 × 10 5 Gy of β or γ) will fall short of the level required to greatly change the properties of glass (10 18 α decays per gram and 10 8