NUCLEAR REACTOR THEORY

Course objectives

The objective of the course is to provide a general comprehension of the physical phenomena underlying the slowing-down and diffusion/transport of neutrons in media without and with nuclear fuel, and to illustrate the mathematical tools necessary to carry out criticality calculations. As a learning outcome, the student is expected to be able to perform and interpret analytical calculations relative to the neutronic design of a nuclear reactor, both in static and dynamic conditions.

Channel 1
RENATO GATTO Lecturers' profile

Program - Frequency - Exams

Course program
1. Introduction to reactor physics 2. Mean free path 3. Fick’s law and diffusion equation 4. Slowing down of neutrons 4.1 Elastic scattering 4.2 Scattering law 4.3 Mean logarithmic decrement 4.4 Slowing down power and moderation ratio 4.5 Lethargy 5. Slowing-down in infinite, non-absorbing media 5.1 Slowing-down in hydrogen 5.2 Slowing-down density in hydrogen 5.3 Slowing-down in media containing media with atomic mass greater than one 5.4 Slowing-down in a system containing different nuclides 6. Slowing-down in infinite absorbing media 6.1 Slowing-down with capture in hydrogen moderator. Resonance escape probability 6.2 Slowing-down in media containing nuclei with atomic mass greater than one 6.3 Resonance escape probability with well-separated resonances 7. Neutron diffusion (basic transport approximation) 7.1 Transport correction 7.2 Transport mean free path 7.3 Diffusion equation 7.4 Boundary conditions 7.5 Solutions of the diffusion equation 7.6 Point-like source in an infinite media 7.7 Infinite plain source 7.8 Infinite plain source in a media of finite thickness 7.9 Plain source with two slabs of finite thickness 7.10 Diffusion length 7.11 Albedo 8. Neutron “age” theory 8.1 Continuous slowing-down model 8.2 “Age” equation without captures 9. The homogeneous thermal reactor without reflector 9.1 Crtical equation 9.2 Approach to criticality 9.3 Criticality condition 9.4 Material and geometric buckling 9.5 Generation time 9.6 Reactors with different geometries 9.6.1 Infinite slab 9.6.2 Rectangular parallelepiped 9.6.3 Sphere 9.6.4 Finite cylinder 10. Subcritical multiplication 11. The homogeneous reactor with reflector 11.1 One group of neutrons 11.2 Infinite plane slab 11.3 Reflector savings 11.4 The ratio between maximum and average flux in a slab reactor 11.5 Two groups of neutrons 12. Transport equation 12.1 Transport theory 12.2 Transport kinetic equation 13. Transport approximations (more sophisticated approximations) 13.1 “Pn” approximation 13.2 Multigroup approximation 14. Multigroup libraries 14.1 The “variable” library. Power iteration method. 14.2 The “ABBN” library 15 Kinetic equation 15.1 The inhour equation 15.2 Solution with one precursor family 16 Reactivity coefficients (p, f , PN L ) 17 Nonlinear reactor dynamics 18 Poisoning due to fission products 18.1 Poisoning due to Xenon 18.2 Poisoning due to Samarium 19 Burnup and fuel cycle 20 Heterogeneous reactor 20.1 Microscopic reactor physics (K factor) 20.1 Macroscopic reactor physics 21 Perturbation theory (optional) 21.1 Adjoint flux 21.2 Perturbative formulation of reactivity
Prerequisites
1st level degree in Engineering or Physics.
Books
"The elements of nuclear reactor theory" by Glasstone and Edlund. Lecture notes distributed by the Instructor.
Exam mode
Assessment of the student's ability to describe qualitatively (in words) and quantitatively (with mathematical formulas) the physical phenomena underlying neutronincs applied to the nuclear fission reactor core. The student will also be expected to present and comment on the results of the assigned project, demonstrating mastery of the mathematical and numerical procedures used.
  • Lesson code1052120
  • Academic year2024/2025
  • CourseEnergy Engineering
  • CurriculumScienze e tecnologie nucleari
  • Year1st year
  • Semester2nd semester
  • SSDING-IND/19
  • CFU9
  • Subject areaIngegneria energetica e nucleare