Granular Sorbents for Passive Environment Protection System during Severe Accidents with Total Loss of Power Supply at NPPs

摘要

Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences has developed some novel sorbents designed for the filter units of the passive filtration system for radioactive discharge from the intercontainment space during heavy accidents with a complete loss of electricity supply at nuclear power plants. These are granulated sorbents based on large-pore silica gel containing nanometric particles of Ag or Ag-Ni compounds (trademark Fizkhimin). The sorbents allow to remove various radioactive iodine species (inorganic ones and methyl iodide) from a steam-gas phase with at least 104 decontamination factor. The high sorption properties of Fizkhimin sorbent with Ag particles were confirmed during tests at a test facility of the TUV Sudwest company (Karlsruhe, Germany). This passive filtration system is installed at the 1st and 2nd units of the Kudankulam nuclear power plant (India) and it is unique in the world practice.