Radiation induced decomposition of nitrogen

Effect of external gamma irradiation on dissolution of the spent UO2 fuel matrix

“…Reactions between water radiolysis products and dissolved nitrogen in solution apparently do not generate nitrogen compounds because of their slow kinetics [24,25]. We verified this assumption by three gamma irradiation experiments in our experimental setup without leachable material over a 2-week period at various solution volume to gas volume ratios.…”

“…Sattonnay [23] obtained results for uranium release from the UO 2 /water interface under intense external alpha irradiation (3.30 · 10 10 a cm À2 s 1 ) that generated 4.8 · 10 À4 mol L À1 H 2 O 2 in the homogeneous solution (S/V = 2.8 m À1 ), compared with the results of experiment1, which generated 1.2 · 10 À4 mol L À1 H 2 O 2 in the homogeneous solution (S/V = 1.3 m À1 ); the 1-hour [24,25], precipitation of a secondary phase [23], a return to equilibrium with the CO 2 partial pressure of the air (pH eq = 5.4 if P CO 2 = 10 À3.5 atm), could account for the acidification of the leachate and warrant further discussion.…”

Leach testing at 50°C of α-doped SON68 glass alteration gels

“…The pH observed during the leaching of the inactive, Np-and Pu-doped gels was about 8.8 ± 0.1 whereas the value measured for Am-doped gel was about 0.5 unit lower. This phenomenon was due to gamma radiolysis of the N 2 -O 2 -H 2 O system leading to the formation of nitric acid among other compounds [1,2] and to c radiationinduced effects on carbonate-bicarbonate-CO 2 (g) equilibrium [3]. Under reducing conditions, the overall pH variation during leaching of Pu-doped gel was similar to the trend observed during the test under oxidizing conditions, except that the values measured between 3 months and 1 year were lower by about 0.3 unit on average.…”

Hydrazine and Hydrogen Co-injection to Mitigate Stress Corrosion Cracking of Structural Materials in Boiling Water Reactors (IV)

“…However, the production efficiency of nitrate ion from N 2 under irradiation conditions is very low. 2,14) In addition, nitrate and nitrite can be removed by their chemical reduction to ammonia. Nitrate and nitrite react with hydrogen to form ammonia in the HWC.…”

“…Fistly, the production efficiency of nitrate ion from N 2 under irradiation conditions is very low. 2,14) Secondly, nitrate and nitrite react with hydrogen to form ammonia in the HWC. 15) Thirdly, no significant amount of nitrate and nitrite was detected in our experiments with hydrazine.…”