Effects of process-generated hydrogen on RPV walls

5. Hydrogen production in PWR

Table 5.1: G-value for each specie in the primary water and for each type of radiation measured at 285 ◦ C. [68, 69]

G G α [69] No./100eV No./100eV No./100eV γ [68] G n [68]

Chemical species

e –

4.15 1.08 3.97 4.15 0.00 0.00 0.00 0.62 1.25 0.00 0.00 0.00 0.00 0.00

0.93 0.50 1.09 0.93 0.00 0.00 0.00 0.88 0.99 0.00 0.04 0.00 0.00 0.00

0.13 0.12 0.45 0.13 0.00 0.00 0.00 1.65 1.55 0.00 0.00 0.00 0.00 0.00

H

OH H +

OH –

O 2

O – 2

H 2

H 2 O 2 HO – 2

HO 2

O –

O

O 2– 2

As the radiolytic production of each specie is known at this moment, the next step is including the chemical reactions between these species. A total set of 60 equations is considered in the model: 1. e – + H 2 O −−→ H + OH – 2. e – + H + −−→ H 3. e – + OH −−→ OH – 4. e – + H 2 O 2 −−→ OH + OH – 5. H + H −−→ H 2 6. e – + HO 2 −−→ HO – 2 7. e – + O 2 −−→ O – 2 8. 2e – + 2H 2 O −−→ 2OH – + H 2 9. OH + OH −−→ H 2 O 2 10. OH + HO 2 −−→ H 2 O + O 2 11. OH + O – 2 −−→ OH – + O 2 12. OH – + H −−→ e – + H 2 O 13. e – + H + H 2 O −−→ OH – + H 2 14. e – + HO – 2 + H 2 O −−→ OH + 2OH – 15. H + + OH – −−→ H 2 O 16. H 2 O −−→ H + + OH – 17. H + OH −−→ H 2 O 18. OH + H 2 −−→ H + H 2 O 19. OH + H 2 O 2 −−→ H 2 O + HO 2 20. H + H 2 O 2 −−→ OH + H 2 O 21. H + O 2 −−→ HO 2 22. HO 2 −−→ O – 2 + H +

48