Hydrogen Induced Embrittlement on Zircaloy-4 Doug Ogletree, Glen Rose I.S.D. Dr. Lin Shao, Texas A&M University, Department of Nuclear Engineering Engineering Dr. Wayne Kinnison, Texas A&M University—Kingsville, Department of Physics

Overview My research project involves the cladding material that covers fuel rods in a nuclear reactor. The material of interest in this project is Zircaloy-4.My research project involves the cladding material that covers fuel rods in a nuclear reactor. The material of interest in this project is Zircaloy-4. Oxidative reaction of zirconium with water releases hydrogen gas, which partly diffuses into the alloy and forms zirconium hydrides.Oxidative reaction of zirconium with water releases hydrogen gas, which partly diffuses into the alloy and forms zirconium hydrides. The hydrides are less dense and are weaker mechanically than the alloy; their formation results in blistering and cracking of the cladding – a phenomenon known as hydrogen embrittlement.The hydrides are less dense and are weaker mechanically than the alloy; their formation results in blistering and cracking of the cladding – a phenomenon known as hydrogen embrittlement.

My Assignment The project is interested in studying the effect of hydrogen accumulation in Zircaloy-4 and how it causes the material to become brittle over time and try to understand how to lengthen the material’s stability.The project is interested in studying the effect of hydrogen accumulation in Zircaloy-4 and how it causes the material to become brittle over time and try to understand how to lengthen the material’s stability. The samples were characterized using nano- and micro-indentation techniques.The samples were characterized using nano- and micro-indentation techniques. A measure of the depth of the indentations as a function of the applied force helps provide some insight into the embrittlement of the alloy.A measure of the depth of the indentations as a function of the applied force helps provide some insight into the embrittlement of the alloy.

Conceptual Design of the Project There will be one main area of concentration in this project: Oxidation-Reduction of Metals.There will be one main area of concentration in this project: Oxidation-Reduction of Metals. The AP Chemistry students will design protocols and set-up and demonstrate their procedures to determine how a variety of common metals may be organized based on their ability to oxidize or reduce.The AP Chemistry students will design protocols and set-up and demonstrate their procedures to determine how a variety of common metals may be organized based on their ability to oxidize or reduce. Once the students are familiar with oxidation- reduction and reduction potentials, they will have to begin applying some engineering design to perform their activities. This will give the instructor the opportunity to address some of the design ideas.Once the students are familiar with oxidation- reduction and reduction potentials, they will have to begin applying some engineering design to perform their activities. This will give the instructor the opportunity to address some of the design ideas.

Anticipated Design Ideas Metals reacting with AcidMetals reacting with Acid

Anticipated Design Ideas Metals reacting with heated Hydrogen PeroxideMetals reacting with heated Hydrogen Peroxide

Anticipated Design Ideas Metals reacting with other reagents.Metals reacting with other reagents.

Anticipated Design Ideas Metals heated to high temperatures.Metals heated to high temperatures.

Timeline Day 1 :Day 1 : A brief review of Redox, definitions and terms. An introduction to material safety will be presented (possibly a pre-test). A brief review of Redox, definitions and terms. An introduction to material safety will be presented (possibly a pre-test) The students must first pass the material safety test (will allow two days for preparation for this test). The students must first pass the material safety test (will allow two days for preparation for this test).

Timeline Day 2 :Day 2 : Engineering Design lesson –In simple context, a brief overview of some of the basic engineering design concepts and principles will be presented. Engineering Design lesson –In simple context, a brief overview of some of the basic engineering design concepts and principles will be presented. The groups will be assigned (three to four students per group). The groups will be assigned (three to four students per group).

Timeline Day 3 :Day 3 : Material safety test will be administered. Material safety test will be administered. One or more redox demonstrations will be performed. Here, I plan to use single-replacement reactions such as aluminum reacting with hydrochloric acid and iron reacting with copper (II) chloride. One or more redox demonstrations will be performed. Here, I plan to use single-replacement reactions such as aluminum reacting with hydrochloric acid and iron reacting with copper (II) chloride. Students will begin collaboration with their teams. They will also be asked to design a laboratory set up in order to measure the changes they will observe. Students will begin collaboration with their teams. They will also be asked to design a laboratory set up in order to measure the changes they will observe.

Timeline Day 4 :Day 4 : Student design time – The students will collaborate with their teams to find solutions, come up with design ideas to create protocols and set-up and demonstrate their procedures to determine how a variety of common metals may be organized based on their ability to oxidize or reduce. Student design time – The students will collaborate with their teams to find solutions, come up with design ideas to create protocols and set-up and demonstrate their procedures to determine how a variety of common metals may be organized based on their ability to oxidize or reduce. The metals that will be used are magnesium, aluminum, zinc, iron, tin and lead. The metals that will be used are magnesium, aluminum, zinc, iron, tin and lead. Each group is expected to produce a different protocol. Each group is expected to produce a different protocol.

Timeline Day 5 and 6 :Day 5 and 6 : Design trial and re-design time. Design trial and re-design time. Realistically, we will need two days for this phase. Realistically, we will need two days for this phase. Since each group will need some set-up time, we will need approximately 20 minutes for each group to set up and perform their demonstrations. Since each group will need some set-up time, we will need approximately 20 minutes for each group to set up and perform their demonstrations.

Timeline Day 7 :Day 7 : Final design presentations – 15 minutes per team. Final design presentations – 15 minutes per team. Day 8 :Day 8 : Post-test – terms, definitions, problems. Post-test – terms, definitions, problems.

Sample Questions _____ 1. Oxidation is ______._____ 1. Oxidation is ______. A)a gain of electrons. A)a gain of electrons. B)a loss of electrons. B)a loss of electrons. C)a gain of protons. C)a gain of protons. D)a loss of protons. D)a loss of protons.

Sample Questions _____ 3. Given the redox reaction: 2I - (aq) + Br 2 (l) -> 2Br - (aq) + I 2 (s) What occurs during this reaction?_____ 3. Given the redox reaction: 2I - (aq) + Br 2 (l) -> 2Br - (aq) + I 2 (s) What occurs during this reaction? A)The I - ion is oxidized, and its oxidation number increases. A)The I - ion is oxidized, and its oxidation number increases. B)The I - ion is oxidized, and its oxidation number decreases. B)The I - ion is oxidized, and its oxidation number decreases. C) The I - ion is reduced, and its oxidation number increases. C) The I - ion is reduced, and its oxidation number increases. D)The I - ion is reduced, and its oxidation number decreases. D)The I - ion is reduced, and its oxidation number decreases.

Relevant End-of-Course (EOC) Objectives (C.4) Science concepts. The student knows the characteristics of matter and can analyze the relationships between chemical and physical changes and properties. The student is expected to(C.4) Science concepts. The student knows the characteristics of matter and can analyze the relationships between chemical and physical changes and properties. The student is expected to (A) differentiate between physical and chemical changes and properties;(A) differentiate between physical and chemical changes and properties; (B) identify extensive and intensive properties;(B) identify extensive and intensive properties; (C.7)(C.7) (D) describe the nature of metallic bonding and apply the theory to explain metallic properties such as thermal and electrical conductivity, malleability, and ductility;(D) describe the nature of metallic bonding and apply the theory to explain metallic properties such as thermal and electrical conductivity, malleability, and ductility; C.11) Science concepts. The student understands the energy changes that occur inC.11) Science concepts. The student understands the energy changes that occur in (A)chemical reactions. The student is expected to understand energy and its forms, including kinetic, potential, chemical, and thermal energies;(A)chemical reactions. The student is expected to understand energy and its forms, including kinetic, potential, chemical, and thermal energies; (C.10)(C.10) (H) understand and differentiate among acid-base reactions, precipitation reactions, and oxidation-reduction reactions;(H) understand and differentiate among acid-base reactions, precipitation reactions, and oxidation-reduction reactions;

Relevant End-of-Course (EOC) Objectives (C.1) Scientific processes. The student, for at least 40% of instructional time, conducts laboratory and field investigations using safe, environmentally appropriate, and ethical practices. The student is expected to(C.1) Scientific processes. The student, for at least 40% of instructional time, conducts laboratory and field investigations using safe, environmentally appropriate, and ethical practices. The student is expected to (A) demonstrate safe practices during laboratory and field investigations, including the appropriate use of safety showers, eyewash fountains, safety goggles, and fire extinguishers;(A) demonstrate safe practices during laboratory and field investigations, including the appropriate use of safety showers, eyewash fountains, safety goggles, and fire extinguishers; (B) know specific hazards of chemical substances such as flammability, corrosiveness, and radioactivity as summarized on the Material Safety Data Sheets (MSDS); and(B) know specific hazards of chemical substances such as flammability, corrosiveness, and radioactivity as summarized on the Material Safety Data Sheets (MSDS); and (C) demonstrate an understanding of the use and conservation of resources and the proper disposal or recycling of materials.(C) demonstrate an understanding of the use and conservation of resources and the proper disposal or recycling of materials. C.2) Scientific processes. The student uses scientific methods to solve investigative questions.C.2) Scientific processes. The student uses scientific methods to solve investigative questions. (C.3) Scientific processes. The student uses critical thinking, scientific reasoning, and problem solving to make informed decisions within and outside the classroom.(C.3) Scientific processes. The student uses critical thinking, scientific reasoning, and problem solving to make informed decisions within and outside the classroom.

Acknowledgements TAMU E 3 ProgramTAMU E 3 Program National Science FoundationNational Science Foundation Nuclear Power InstituteNuclear Power Institute Dr. Lin ShaoDr. Lin Shao Dr. Wayne KinnisonDr. Wayne Kinnison Michael MartinMichael Martin Richard VegaRichard Vega Josey WallaceJosey Wallace Michael GeneralMichael General