Grant: Collaborative Research and Development Grants
University of Western Ontario
$48,000.00
Mechanical and chemical indicators for SCC in Alloy 800 steam generator tubing
FY 2010-11
Summary
Stress corrosion cracking (SCC) of Alloy 600 steam generator (SG) tubing is a major issue both CANDU and PWR nuclear reactors. Replacement Alloy 800 (A800) tubing is also not immune to SCC; cracking has recently been reported in Europe. To improve the prediction of the onset of cracking in Alloy 800 under service conditions, the interplay of mechanical and chemical behaviour of this material be thoroughly understood. The effects of chemical environments are well known; the effects on mechanical stress on a microscopic scale are less well understood and their combined effects therefore have not been well characterized. A current industry-sponsored research project has focused on this aspect for the stress corrosion cracking of Alloy 600 SG tubing materials and the project team has developed methodologies for determining the microstrain, grain boundary precipitation and microstructure of the samples exhibiting intergranular cracking. More importantly, some progress has also been made in understanding how these parameters contribute to the crack growth process. Thus, the next step is apply some of these methodologies to study the SCC behaviour of Alloy 800 SG tubing material, the current material choice for CANDU reactors and the specified material for Advanced CANDU reactors (ACRs).
Three tasks have been proposed for the research program. The first task is to determine the conditions that would induce intergranular cracking in a controlled manner. Outcome from the second task would help us to determine the factors that that control the cracking of Alloy 800 SG tubing and would also be used to explain the enhanced SCC resistance of Alloy 800 compared to Alloy 600. The third task focuses on the examination of SG tubing material removed from service. This task is of central importance to degradation assessments contained in the Life-Cycle Management (LCM) plans of CANDU power reactors.
The proposed research would take place within the multi-university/industry research consortium that has already been established as part of the current research program.
Program
Collaborative Research and Development Grants
Recipient
Location
Ontario, Canada
Recipient Type
Academia
Type
Grant
Source
NSERC's Awards Data
As published
Application id
402744-2010
Name nom
Lau, Leo
Department département
Surface Science Western
Organization id
36
Institution établissement
University of Western Ontario
Province en
Ontario
Province fr
Ontario
Country en
CANADA
Country fr
CANADA
Fiscal year exercice financier
2010
Competition year année de concours
2010
Award amount
48000
Program id
CRDPJ
Program name en
Collaborative Research and Development Grants
Program name fr
Subventions de recherche et développement coopérative
Group en
Research partnerships programs
Group fr
Programmes de partenariat
Committee code
96
Committee name en
RPP Internal Decision Cttee
Committee name fr
Cté de décision interne - PPR
Area of application code
1208
Area of application group en
Advancement of knowledge
Area of application group fr
Avancement des connaissances
Area of application en
Materials sciences
Area of application fr
Sciences des matériaux
Research subject code
2400
Research subject group en
Nuclear engineering
Research subject group fr
Génie nucléaire
Research subject en
Nuclear engineering
Research subject fr
Génie nucléaire
Partie
1
Nb partie
3
Application title
Mechanical and chemical indicators for SCC in Alloy 800 steam generator tubing
Keyword
NSERC
Application summary
Stress corrosion cracking (SCC) of Alloy 600 steam generator (SG) tubing is a major issue both CANDU and PWR nuclear reactors. Replacement Alloy 800 (A800) tubing is also not immune to SCC; cracking has recently been reported in Europe. To improve the prediction of the onset of cracking in Alloy 800 under service conditions, the interplay of mechanical and chemical behaviour of this material be thoroughly understood. The effects of chemical environments are well known; the effects on mechanical stress on a microscopic scale are less well understood and their combined effects therefore have not been well characterized. A current industry-sponsored research project has focused on this aspect for the stress corrosion cracking of Alloy 600 SG tubing materials and the project team has developed methodologies for determining the microstrain, grain boundary precipitation and microstructure of the samples exhibiting intergranular cracking. More importantly, some progress has also been made in understanding how these parameters contribute to the crack growth process. Thus, the next step is apply some of these methodologies to study the SCC behaviour of Alloy 800 SG tubing material, the current material choice for CANDU reactors and the specified material for Advanced CANDU reactors (ACRs).
Three tasks have been proposed for the research program. The first task is to determine the conditions that would induce intergranular cracking in a controlled manner. Outcome from the second task would help us to determine the factors that that control the cracking of Alloy 800 SG tubing and would also be used to explain the enhanced SCC resistance of Alloy 800 compared to Alloy 600. The third task focuses on the examination of SG tubing material removed from service. This task is of central importance to degradation assessments contained in the Life-Cycle Management (LCM) plans of CANDU power reactors.
The proposed research would take place within the multi-university/industry research consortium that has already been established as part of the current research program.
