Evaluation of crack growth of chloride-induced stress corrosion cracking in dry storage system under different environmental conditions

2020 ◽  
Vol 130 ◽  
pp. 103534
Author(s):  
Wen-Yu Wang ◽  
Yung-Shin Tseng ◽  
Tsung-Kuang Yeh
Keyword(s):  
Stress Corrosion ◽  
Crack Growth ◽  
Stress Corrosion Cracking ◽  
Environmental Conditions ◽  
Storage System ◽  
Corrosion Cracking ◽  
Dry Storage ◽  
Induced Stress

scholarly journals Crack Growth Rate Testing With Instrumented Bolt-Load Compact Tension Specimens Under Chloride-Induced Stress Corrosion Cracking Conditions in Spent Nuclear Fuel Canisters

2017 ◽  
Author(s):  
Andrew J. Duncan ◽  
Poh-Sang Lam ◽  
Robert L. Sindelar ◽  
Joe T. Carter
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Stress Corrosion ◽  
Crack Growth ◽  
Stress Corrosion Cracking ◽  
Crack Front ◽  
Spent Nuclear Fuel ◽  
Compact Tension ◽  
Corrosion Cracking ◽  
Induced Stress

Stress corrosion cracking (SCC) may occur when chloride-bearing salts and/or dust deliquesce on the external surface of the spent nuclear fuel (SNF) canister at weld residual stress regions. An SCC growth rate test is developed using instrumented bolt-load compact tension specimens using the American Society for Testing Materials (ASTM) specification E1681 with an experimental apparatus that allows an initially dried salt to deliquesce and infuse naturally to the crack front under temperature and humidity parameters relevant to the canister storage environmental conditions. The shakedown tests were conducted over a range of relative humidity controlled by the guidance in ASTM E104 at 50 °C with salt assemblages of (1) mixture of artificial dust and deliquescent salts (2) a mixture of artificial dust and salt from dehydrated sea water. After five months exposure the specimens were examined for evidence of chloride induced stress corrosion cracking (CISCC) and observations are reported for both salt/dust mixtures. The test specimen and apparatus designs will be modified to enhance the interaction between the deliquescing salt and the crack front for more accurate characterization of the crack growth rate as a function of stress intensity factor, which is an essential input to the determination of in-service inspection frequency of SNF canisters.

Modeling the Interactions of Hydrogen, Stress and Dissolution in Near-Neutral pH Stress Corrosion Cracking of Pipelines

2006 ◽  
Author(s):  
Frank Y. Cheng
Keyword(s):  
Stress Corrosion ◽  
Dissolution Rate ◽  
Crack Growth ◽  
Anodic Dissolution ◽  
Hydrogen Concentration ◽  
Stress Corrosion Cracking ◽  
Crack Tip ◽  
Corrosion Cracking ◽  
Neutral Ph ◽  
Ph Stress

A thermodynamic model was developed to determine the interactions of hydrogen, stress and anodic dissolution at the crack-tip during near-neutral pH stress corrosion cracking in pipelines. By analyzing the free-energy of the steel in the presence and absence of hydrogen and stress, it is demonstrated that a synergism of hydrogen and stress promotes the cracking of the steel. The enhanced hydrogen concentration in the stressed steel significantly accelerates the crack growth. The quantitative prediction of the crack growth rate in near-neutral pH environment is based on the determination of the effect of hydrogen on the anodic dissolution rate in the absence of stress, the effect of stress on the anodic dissolution rate in the absence of hydrogen, the synergistic effect of hydrogen and stress on the anodic dissolution rate at the crack-tip and the effect of the variation of hydrogen concentration on the anodic dissolution rate.

Weld Residual Stresses and Primary Water Stress Corrosion Cracking in Bimetal Nuclear Pipe Welds

2007 ◽  
Author(s):  
Frederick W. Brust ◽  
Paul M. Scott
Keyword(s):  
Water Stress ◽  
Residual Stresses ◽  
Weld Metal ◽  
Stress Corrosion ◽  
Crack Growth ◽  
Stress Corrosion Cracking ◽  
Pressure Vessel ◽  
Large Diameter ◽  
Corrosion Cracking ◽  
Primary Water

There have been incidents recently where cracking has been observed in the bi-metallic welds that join the hot leg to the reactor pressure vessel nozzle. The hot leg pipes are typically large diameter, thick wall pipes. Typically, an inconel weld metal is used to join the ferritic pressure vessel steel to the stainless steel pipe. The cracking, mainly confined to the inconel weld metal, is caused by corrosion mechanisms. Tensile weld residual stresses, in addition to service loads, contribute to PWSCC (Primary Water Stress Corrosion Cracking) crack growth. In addition to the large diameter hot leg pipe, cracking in other piping components of different sizes has been observed. For instance, surge lines and spray line cracking has been observed that has been attributed to this degradation mechanism. Here we present some models which are used to predict the PWSCC behavior in nuclear piping. This includes weld model solutions of bimetal pipe welds along with an example calculation of PWSCC crack growth in a hot leg. Risk based considerations are also discussed.

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