Energy Engineering

Course Presentation and Introduction to Fusion Technology. The case for fusion energy. History of fusion research. Tokamak reactor systems and components. Technical challenges for the development of fusion energy. Basic Design of a Tokamak-based Fusion Power Plant. Engineering, economic, and nuclear constraints for a fusion power plant. Design of reactor geometry from basic principles. Metrics used to evaluate plasma performance for the primitive design. Discussion and design optimization. The Magnet System. Outline of magnet system in a tokamak reactor. Pulsed operation. Supeconductivity. Low and high temperature superconductors. High temperature superconductors. Coil structure and manufacturing. Electromagnetic forces. Cryogenic cooling. Quench and coil protection. Plasma Heating, Control, and Diagnostics. Plasma heating systems. Inductive ohmic heating. Neutral Beam Injectors (NBI). Radio-frequency heating. Plasma control. Position and shape control. Non-inductive current drive. Plasma diagnostics. Roles and functions. Type of diagnostics. Diagnostics for ITER and DEMO. Plasma-facing Components. Part I: Particle and Power Exhaust Control. Impurity production processes. Effect of impurities on plasma parameters. Hydrogen recycling. Strategy to control particle exhaust. Plasma power flow. Static heat loads on plasma-facing components. Divertor protection. Heat loads due to plasma transients: disruptions and Edge Localized Modes (ELMs). Disruption mitigation. Advanced magnetic configurations. Plasma-facing Components. Part II: Design and Technology. Design of High Heat Flux (HHF) components. ITER Plasma-facing Components. The Blanket Module. The water-cooled divertor. DEMO Plasma-facing Components. Specific challenges for DEMO First Wall. First Wall protection through sacrificial limiters. DEMO divertor: core seeding and target sweeping. Advanced divertor configurations. The Divertor Test Tokamak. Liquid metal plasma-facing components. Vacuum Vessels and Pumping. Viscous flow and molecular flow. Vacuum pumping system. Operational requirements. Roles and functions. Vacuum vessel and cryostat. Structural Materials for Fusion. Requirements and criteria for material selection. Fundamentals of material science. Mechanisms of irradiation damage. Difference between damage in fission and fusion reactors. Eurofer: a Reduced Activation Ferritic Martensitic (RAFM) steel. Irradiation effects on material properties and the case in Eurofer. The International Fusion Materials Irradiation Facility and the Demo-Oriented NEutron Source (IFMIF-DONES). Breeding Blanket. Part I: The fuel cycle and tritium breeding. Tritium. Tritium reserves and the rational for breeding. Fundamentals of tritium breeding. Tritium Breeding Ratio (TBR). The fuel cycle of a fusion reactor. Tritium extraction technology. The tritium plant. Fueling system. Breeding Blanket. Part II: The blanket architecture. Blanket roles and functions. Architecture. Breeding materials. Coolants. Requirements. The Test Blanket Module (TBM) programme in ITER. Integration with other tokamak systems. Balance Of Plant (BOP). Breeding Blanket. Part III: Liquid breeder blankets. Advantages and drawbacks. Corrosion and material compatibility. Magnetohydrodynamic issues for blanket design. The Water Cooled Lithium Lead (WCLL) blanket. Breeding Blanket. Part IV: Solid breeder blankets. Advantages and drawbacks. Operational requirements for solid breeders. Manufacturing. The Helium Cooled Pebble Bed (HCPB) blanket.

A basic background in nuclear engineering and power conversion is helpful, but not strictly required. The course is designed to be accessible to students from diverse technical backgrounds, especially those who are completely new to nuclear engineering. The fusion field needs contributions from many disciplines (plasma physicists, electrical engineers, materials scientists, computer scientists; just to name a few), so all are welcome. That said, to get the most out of the course, students should be familiar with topics typically encountered in bachelor-level engineering and physics courses: thermodynamics and heat transfer, materials science, and electromagnetism.

Van Oost, G. & Gonzalez de Vicente, S. M. Fundamentals of Magnetic Fusion Technology (2023). IAEA. Available online. Freidberg, J. (2007). Plasma Physics and Fusion Energy. Cambridge University Press. New York. Dolan, T.J. (2013). Magnetic Fusion Technology. Springer. London. Lecture notes distributed by the teacher.

Lectures will be delivered in person.

The course is delivered in presence according to the official timetable released by the University. Lectures are typically recorded (depending on the state of the in-class equipment) and are then distributed through the course website. Transcripts may be produced upon request. No minimum attendance is requested. The course is entirely taught in English.

The evaluation procedure is divided into two phases: the first one concerns the performance and presentation of a capstone project, while the second one is dedicated to an oral examination of the student on the course programme. The capstone project is intended as an opportunity for the student to improve their understanding and problem-solving skills on one of the topics discussed during the course. An assignment describing the project objectives and including relevant information will be provided by the teacher during the semester. The workload estimated for the project completion is about one week. The project evaluation is individual, but cooperation across the student cohort is encouraged. The project should be completed at least one week prior to the oral examination that will be scheduled on a date agreed by both parties (teacher and student) beforehand (but always within the allowed exam periods). The oral examination will involve the presentation (≈10 minutes) of the capstone project methodology and results, followed by a brief discussion (≈5 minutes). A satisfactory completion of the project is a prerequisite to move to the second phase of the exam and accounts for approximately one-third of the student grade. The second part of the oral examination (≈45 to 60 minutes) will involve the discussion of three main subjects, each carrying the same weight in the grade calculation. Examples of typical exam questions include: Elements of fusion energy: discussion of a conceptual layout of a fusion power plant based on the tokamak approach to magnetic confinement; definition of scientific, technical and economic feasibility of fusion energy. Technical challenges of fusion energy: definition and discussion of one of the challenges of fusion energy: confinement and control, exhaust, fuel, materials, and integration. Fusion reactor technology: more detailed discussion of one specific aspect of fusion technology. Examples: design criteria for superconducting coils, technologies for heating and non-inductive driving of plasma currents, plasma power balance and estimate of divertor static heat load, design criteria for high heat flux components, the vacuum pumping system in a fusion reactor, etc.

T. Dolan, Fusion Research: Principles, Experiments and Technology, Corrected Edition, 2000, Pergamon Press , downloadable at the link: https://bit.ly/3bPOQqx Useful references: M. Caira, M. Cumo: “Ingegneria dei reattori nucleari a fusione”, Ente per le Nuove tecnologie, l’Energia e l’Ambiente, Trattati (febbraio 1991). Weston M. Stacey, Fusion: An Introduction to the Physics and Technology of Magnetic Confinement Fusion, 2nd Edition, ISBN: 978-3-527-40967-9, 262 pages, February 2010

Lectures will be delivered in person.