Multivariable analysis of the effects of Li, H{sub 2}, and pH on PWR primary water stress corrosion cracking. Final report
The effects of Li, pH and H, on primary water stress corrosion cracking (PWSCC) of Alloy 600 were investigated for temperatures between 320 and 330{degrees}C. Specimens included in the study were reverse U-bends (RUBs) made from several different heats of Alloy 600. The characteristic life, {eta}, which represents the time until 63.2% of the population initiates PWSCC, was computed using a modified Weibull statistical analysis algorithm and was analyzed for effects of the water chemistry variables previously mentioned. It was determined that the water chemistry variables are less sensitive than the metallurgical characteristics defined by the heat, heat treatment and initial stress state of the specimen (diameter and style of RUB); the maximum impact of chemistry effects was 0.13 to 0.59 standard deviations compared to a range of three (3) standard deviations for all variables. A first-order model was generated to estimate the effect of changes in pH, Li and H, concentrations on the characteristic life. The characteristic time to initiate cracks, {eta}, is not sensitive to Li and H{sub 2} concentrations in excess of 3.5 ppm and 25 ml/kg, respectively. Below these values, (1) {eta} decreases by {approximately}20% when [Li] is increased from 0.7 to 3.5 ppm; (2) {eta} decreases by {approximately}9% when [H{sub 2}] is increased from 13.1 to 25.0 ml/kg; and (3) {eta} decreases by {approximately}14% when pH is increased from 7.0 to 7.4, in each case holding the other two variables constant.
- Research Organization:
- Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Modeling and Computing Services, Boulder, CO (United States)
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 399717
- Report Number(s):
- EPRI-TR-105656; TRN: 96:006377
- Resource Relation:
- Other Information: PBD: May 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Measurement and Calculation of Electrochemical Potentials in Hydrogenated High Temperature Water, including an Evaluation of the Yttria-Stabilized Zirconia/Iron-Iron Oxide (Fe/Fe3O4) Probe as Reference Electrode
Measurement of the Nickel/Nickel Oxide Phase Transition in High Temperature Hydrogenated Water Using the Contact Electric Resistance (CER) Technique