Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Dissertation_final.pdf (3.69 MB)

ETD Abstract Container

Abstract Header

Chloride-Induced Stress Corrosion Cracking in Used Nuclear Fuel Welded Stainless Steel Canisters

Xie, Yi
http://orcid.org/0000-0002-3668-733X
http://rave.ohiolink.edu/etdc/view?acc_num=osu1469132001

Abstract Details

2016, Doctor of Philosophy, Ohio State University, Nuclear Engineering.
The used nuclear fuel (UNF) dry storage is one of the options for the interim storage of UNF. Most of the dry storages are located in coastal and lake/river-side regions. They are designed to serve for 60 years or even more. In most cases, the storage canister which is in a welded austenitic stainless steel (SS) structure will be exposed to a salt-containing environment for the entire storage period. Since the canister is a primary barrier to fission product release, it has been determined to be robust with little degradation due to thermal, mechanical or radiation effects. However, atmospheric and aqueous pitting corrosion, as well as chloride induced stress corrosion cracking (CISCC) may occur because of the aggressive species that form on or contact the canister surface and the residual tensile stresses. The objective of this dissertation is to develop an experimental integrated approach to study the fundamentals of CISCC of Type 304L base metal (BM) and weld metal (WM) and collect data to evaluate CISCC under relevant environmental conditions, and to develop a model based on probabilistic analysis by parameterizing and validating using the experimental studies to predict long-term pitting behaviors of the storage canister. The efforts and findings documented in this dissertation consist of: (1) The electrochemical techniques are used to identify the corrosion potential, passive current, pitting potential, passivation layer impedance of the BM and WM immersed in highly concentrated chloride solutions at 40 and 70 °C. (2) The pitting corrosion resistance in the chloride-containing aqueous and atmospheric environment is evaluated and compared by the pit density and frequency distribution of depth. It is found that the welding process depresses the corrosion resistance of a metal matrix under the investigated environments. Metastable pitting is distinct especially for the early exposure times. The pitting corrosion resistance is influenced by the chloride concentration and the temperature. The findings of pitting corrosion in humid environments provide better forecasting on actual in-service canisters. (3) CISCC experiments with in situ measurement of crack growth rates of the BM and WM exposed to the salt deposit humid environment (15% RH at 70 °C) are conducted in the SCC test system. The WM has much higher SCC growth rate than the BM even with lower applied stress intensity, indicating the SCC resistance of the steel is depressed by the welding process. (4) Micro-characteristics imaging and analytical facilities are used to analyze the microstructure of pitting corrosion and CISCC. (5) The experimental results are used to concurrently parameterize and validate the model based on probabilistic analysis for pitting corrosion. The concept of Markov chain, as well as the pitting corrosion mechanism, is involved in this model to predict the pitting corrosion states, density and depth. Since the safety performance of the storage is major concerned in the nuclear industry, this study provides a technical basis for evaluating the technical issue and supports the development of evaluating SCC occurrence, crack depth and growth rate on in-service storage canisters.
Jinsuo Zhang (Advisor)
Tunc Aldemir (Committee Member)
Marat Khafizov (Committee Member)
Andre Palmer (Committee Member)
177 p.
Nuclear Engineering
Chloride-Induced, Stress Corrosion, Cracking, Used Nuclear Fuel, Welded, Stainless Steel, Canisters

Recommended Citations

Citations

  • Xie, Y. (2016). Chloride-Induced Stress Corrosion Cracking in Used Nuclear Fuel Welded Stainless Steel Canisters [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1469132001

    APA Style (7th edition)

  • Xie, Yi. Chloride-Induced Stress Corrosion Cracking in Used Nuclear Fuel Welded Stainless Steel Canisters. 2016. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1469132001.

    MLA Style (8th edition)

  • Xie, Yi. "Chloride-Induced Stress Corrosion Cracking in Used Nuclear Fuel Welded Stainless Steel Canisters." Doctoral dissertation, Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1469132001

    Chicago Manual of Style (17th edition)

osu1469132001
1,181
© 2016, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.