KYIV, May 20 – The increase in the density of the neutron flux in the Shelter facility occurred after the installation of confinement over the facility, which led to a change in the moisture conditions in the fuel containing materials due to the cessation of atmospheric precipitation into the facility, the Ukrainian Nuclear Society (UNS) reported on Wednesday.

"As a result, the process of evaporation and loss of moisture from the porous structure of lava-like fuel containing materials started, which led to the recorded increase in the neutron flux density," the society said in the press release.