Scheda programma d'esame
Anno accademico2021/22
PeriodoSecondo semestre

Programma non disponibile nella lingua selezionata
Learning outcomes

The student who successfully completes the course will have the ability to identify and select materials to be used for nuclear reactor applications, evaluating their properties from the mechanical, chemical and nulear point of view.

Assessment criteria of knowledge

The student will be assessed on his/her demonstrated ability to discuss the main course contents using the appropriate terminology.

During the exam the student must be able to demonstrate his/her knowledge of the course material and be able to discuss the reading matter thoughtfully and with propriety of expression.

The student's ability to explain correctly the main topics presented during the course at the board will be assessed.



The following main skills are provided by the course:

  • capability to identify different types of metal structures;
  • capability to guess quantitatively some basic phenomena, as elementar mechanical properties;
  • understanding of the main irradiation damage mechanisms in steel and Zr alloy;
  • capability to design the right metallic materials for nuclear reactor and fuel clading;
Assessment criteria of skills

Oral / written examination, with assignment of typical problems.


The course is definitely a "changing mind" one. From the presented material the students are supposed to achieve those attitudes typical of "nuclear culture", i.e., accountability, open and communicating attitude, transparency, questioning attitudes. 

Assessment criteria of behaviors

Basic knowledge about nuclear plants, material science, mechanical test


Basic chemistry

Nuclear reactor physics

Nuclear plants


No specific suggestion for courses to be attended in parallel.

Prerequisites for further study

No specific suggestion.

Teaching methods

Delivery: face to face

Attendance: Advised

Learning activities:

  • attending lectures
  • participation in seminar
  • preparation of oral/written report


Teaching methods:

  • Lectures
  • Seminar
  • project work



First section: Fuel cycle and materials selection criteria

Fundamentals of nuclear reactor systems. Types of reactors: classification in term of neutron energy, reactor purpose, type of coolant.

A simple reactor design. Main characteristics of reactors of Gen I, Gen II, Gen III, and Gen IV reactors.

The nuclear fuel cycle. Finding and mining Uranium: Uranium ores and uranium minerals (reduced species and oxidized species). Basic chemistry concepts on oxidation state of the elements into compounds.

Acid leaching and basic leaching. In-situ leaching. Treatment of uranium solutions; the yellow cake. Refining uranium; liquid-liquid extraction using TBP.

Basic concepts related to a general isotope enrichment process: relative isotopic abundance, separation factor, separation gain, enrichment factor. Enrichment of UF6 by diffusion. Typical diffuser scheme. Diffusion membrane characteristics. Pros and cons of a diffusion plant. Numerical example for an ideal diffusion separation cascade with no-tails; calculation of the minimum number of separation stages in an ideal diffusion cascade.

Basic principles of separation in a force field. Separation in a gravity field. Enrichment of UF6 by centrifugation. The Zippe centrifuge. Pros and cons of a centrifugation plant. Numerical example for an ideal centrifugation separation cascade with no tails; calculation of the minimum number of separation stages in an ideal centrifugation cascade.

Laser isotope separation techniques. Isotope separation based on hyperfine structure. Atomic separation: the AVLSI technique. Molecular separation: the MLIS technique. The aerodynamic separation: the jet nozzle technique. Comparison between different separation techniques.

Fabrication of fuel elements: production of UO2 by humid or dry path.
The back-end operation in the fuel cycle: reprocessing and recycling. The PUREX process: fuel decladding, shearing, dissolution, separation of U and Pu from waste, separation of Pu from U, final product conversion.

General criteria for material selection. Requirements and materials for fuel cladding, moderator and reflectors, coolants, control materials, shielding materials. Example: fuel cladding materials for LWRs; properties of Be, Mg, Al, Zr; Zr based alloys – Zircaloy-2 and Zircaloy-4.

Extraction of Zr from ore; the modified Kroll process. Zr-Hf separation processes: principles and characteristics of the MIBK and TBP processes.

Second section: materials radiation damage

Structure and properties of metallic materials. Elementary cells, Miller and Bravais notation.

Point defects. Linear defects. Dislocations. Classification of crystals and dependence between mechanical properties and crystal structure of materials.

The role of imperfections, state of stress, temperature and strain rate in mechanical properties.

Interaction of neutrons with matter: capture and scattering. Collision cross-sections, neutron flux and mean free path. Radiation damage: knock-on damage, transmutation, bubble formation, swelling.

Collision theory: displacement threshold, cut-off energy. Damage geometry: displacement spike, thermal spike.

Effects of radiation on physical and mechanical properties Enhanced diffusivity, creep, phase stability, radiation hardening, embrittlement and corrosion.

Radiation growth in uranium and graphite, thermal ratcheting of reactor fuel assemblies. Annealing processes. Wigner energy release in graphite.

Radiation-resistant construction steels Overview of structural-integrity issues. Fracture mechanics and non-destructive testing. Stress-corrosion cracking

Nuclear metallurgy Structures and properties of materials with special relevance for nuclear power generation: zirconium and zr-alloys

Pressure vessel and cladding. stainless steel for nuclear applications.

Example of radiation damage in nuclear plant. Stress corrosione cracking and hydrogen embrittlement.


Benjamin M. Ma - Nuclear Reactor Materials and Applications

Gary S. Was - Fundamentals of Radiation Materials Science

W. Hoffelner - Materials for Nuclear Plants

Material supplied by the teacher.

Non-attending students info

The teaching material, updated year by year by the teacher, is available on a usb support.

The teacher is available with continuity to receive students for solving their learning problems.

Assessment methods

The exam is made up of one written test, and one oral test.
The written test consists of two questions, one for each section of the course. It involves a normal classroom, and is two hours long. The written test will be passed if the score for each question is at least 18/30.
The oral test consists of an interview between the candidate and the lecturers. During the test the ability of the candidate to express him/herself in a clear manner using the correct terminology will be also assessed. The oral test will be passed if the score is at least 18/30.
The final score will be the average of the written and oral scores.

Work placement

The MSc in Nuclear Engineering mainly suggests stages at the end of of the formal education though examinations, favouring the works performed abroad at renown reserach institutions.


For exams, contact or to take engagements.

Ultimo aggiornamento 13/09/2021 08:31