Radiation chemistry of aqueous solutions of hydrazine Part 3. The chain reaction in oxygenated solutions irradiated with 60Co γ-rays

Effect of gamma-ray irradiation on the deoxygenation of salt-containing water using hydrazine

“…In the SFPs of nuclear power plants, the stored highly radioactive spent fuels emit alpha, beta and gamma rays, with the main radiation component being gamma rays. It has been reported that the gamma radiolysis products of N 2 H 4 react with the oxygen molecules, and the DO concentration in a sample of irradiated water is reduced as a result of N 2 H 4 addition [4][5][6][7][8]. However, these data were not obtained for saltcontaining water, but for distilled water.…”

“…It suggests that the chloride ions scavenged preferentially the hydroxyl radical (·OH). The produced H 2 O 2 can decompose according to Equation (8) [16], and thus, it indicates that the rate of decomposition is very slow at room temperature.…”

Nitrogen compounds' formation in aqueous solutions under high ionizing radiation: An overview

“…The radiation chemical changes of hydrazine results in the formation of ammonia, nitrogen and hydrogen in the absence of oxygen and other impurities. Use of hydrazine in the primary coolant of watercooled nuclear power reactors has renewed an interest in its radiation chemistry in aqueous solution (Buxton and Lynch, 1999). The radiation-induced decomposition of oxygen saturated aqueous solutions of N 2 H 4 has been reported over the pH range 3.5-11.7 (Buxton and Lynch, 1999).…”

“…Use of hydrazine in the primary coolant of watercooled nuclear power reactors has renewed an interest in its radiation chemistry in aqueous solution (Buxton and Lynch, 1999). The radiation-induced decomposition of oxygen saturated aqueous solutions of N 2 H 4 has been reported over the pH range 3.5-11.7 (Buxton and Lynch, 1999). It has been suggested that the decomposition of N 2 H 4 (shown in Table 3) proceeds by a pH dependent chain reaction propagated by hydrazil radical ( d N 2 H 3 generated after H-abstraction reaction of N 2 H 4 ) reacting with O 2 , and the resulting HO d 2 =O dÀ 2 radicals further oxidizing N 2 H 4 to d N 2 H 3 .…”

“…Chain termination occurs via self-reactions of HO d 2 =O dÀ 2 radicals. The molecular products N 2 H 2 and H 2 O 2 react further to form N 2 (N 2 H 2 +H 2 O 2 -N 2 +2H 2 O; k bimol ¼ 6Â10 2 M À 1 s À 1 ) (Buxton and Lynch, 1999). Ammonia is the ultimate product of dimerisation of hydrazyl radicals (2 d N 2 H 3 -N 4 H 6 -NH 3 +N 3 H 3 ), however, it is not a product in presence of oxygen as these radicals are sensitive to O 2 (Buxton and Stuart, 1997).…”