Behavior of Nitrogen Compounds in Radiation Field and Nuclear Reactor Systems

Abstract

Formation of nitrogen compounds in N2-H2O systems under radiation was studied. A reaction scheme with 24 species and 73 reactions was proposed. Two trigger reactions for nitrogen atom generation: N2 → 2N (g-value of 1.6 μmol per 1 kJ absorbed energy in N2 molecules), and N2+H2O*→NH2+NO (κ=3.0×109 S−1·M−1 at 298 K with activation energy of 34.4kJ/mol) were included. Calculated results with the reaction scheme agreed within an error factor of two with ammonium formation rates from an aqueous solution with dissolved nitrogen and hydrogen gasses under γ-irradiation at temperatures of 288~473 K. The reaction scheme was also verified with BWR plant observations on nitric acid formation from in-leaked air under hydrogen water chemistry and ammonium injection tests.