Effects of process-generated hydrogen on RPV walls

List of Figures

5.4 Equilibrium pressure of H 2 for a concentration between 25 and 50 STP cm 3 /kg. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 5.5 Pourbaix diagram for Fe-Cr-H 2 O and Fe-H 2 O system at a temperature of 320 ◦ C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 5.6 Density of radiolytic species for high and low LET radiations. . . . . . . 47 5.7 Stability test of the model for extreme conditions. . . . . . . . . . . . . 54 5.8 Variation of H concentration during the fuel cycle. . . . . . . . . . . . . 56 6.1 Equilibrium pressure of H 2 for a concentration of 35 STP cm 3 /kg. . . . 61 6.2 Experimental values for Henry coefficient of noble gases as function of temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 6.3 Relation between the maximum Henry coefficient and the Van der Waals radii of the noble gases. . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 6.4 Relation between the temperature, where the maximum Henry coefficient is reached, and the Van der Waals radii of the noble gases. . . . . . . . . 65 6.5 Henry coefficient in GPa for atomic hydrogen as a function of temperature. 66 6.6 Henry coefficient in mol/m 3 Pa for atomic hydrogen as a function of temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 6.7 Temperature dependence of the H 2 dissociation constant. . . . . . . . . 68 6.8 Concentration of species at begin of cycle in absence of radiation. . . . . 70 6.9 Sieverts’ constant for hydrogen in ferritic steel. . . . . . . . . . . . . . . 73 6.10 Schematic representation of the RPV wall for the diffusion model and its solution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 7.1 Typical cooling path for the reactor coolant in a pressurized water reactor during a cold shutdown. . . . . . . . . . . . . . . . . . . . . . . . 79 7.2 Temperature profile in the RPV wall as a result of the typical cooling path during a cold shutdown. . . . . . . . . . . . . . . . . . . . . . . . . 81 7.3 Concentration profile in the RPV wall as a result of the typical cooling path during a cold shutdown considering only corrosion generated hydrogen with a 10% absorption coefficient and a hydrogen generation rate of 50 mol H/yr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 7.4 The hydrogen fugacity in the RPV wall as function of time due to corrosion. 84 7.5 Concentration profile in the RPV wall as a result of the typical cooling path during a cold shutdown considering only corrosion generated hydrogen with a 10% absorption coefficient and a hydrogen generation rate of 150 mol H/yr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 7.6 Concentration profile in the RPV wall as a result of the typical cooling path during a cold shutdown considering only corrosion generated hydrogen with a 90% absorption coefficient and a hydrogen generation rate of 50 mol H/yr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 7.7 Concentration profile in the RPV wall as a result of the typical cooling path during a cold shutdown considering only corrosion generated hydrogen with a 90% absorption coefficient and a hydrogen generation rate of 150 mol H/yr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 v