Nuclear Instrumentation, Radiation Dosimetry and Protection
Module Title - Reactor Materials, Reactor Systems and NDE
Number of credits – 20
Types of bonding. Types of solids. Phases and phase diagrams (including thermodynamics). Crystal structures. Microstructural defects: point defects – nature, migration and diffusion; perfect dislocations - Burgers vectors, loops; partial dislocations and stacking faults, stacking fault tetrahedra. Properties of materials: mechanical behaviour - strength, toughness, creep and fatigue resistance; corrosion. Metallurgy of reactor materials: steels - plain carbon steel and stainless steel; precipitation hardened alloys e.g. zircaloy; uranium dioxide.
Semester 1, contact hours - 18
The reasons for performing NDT: quality control c.f. fitness-for-purpose. Surface techniques: dye penetrant, magnetic particle testing. Ultrasonics: principles and practical demonstration. Ultrasonics: automated and advanced techniques. Radiography: principles of techniques and image interpretation. Electromagnetic methods: eddy currents, ACFM and practical demonstration. Other NDT techniques e.g. thermography, acoustic emission. Demonstrating NDT reliability. Applications in nuclear power technology. Summary: Comparison of strengths and weakness of techniques.
Semester 2, contact hours - 16.
Nuclear Fuel Cycle
Production of Magnox and AGR fuel from "yellow cake": Chemistry of the steps involved in the operations at the Springfields plant (UK). Nuclear fuel enrichment, theory of cascade processes. Reprocessing of spent nuclear fuel: basic chemistry involved in the processes at the Sellafield works (UK) including THORP; outline of other methods such as fluid -bed volatilization. At the heart of reprocessing in BNFL's THORP reprocessing plant, Sellafield.
Semester 2, contact hours - 6.
Nuclear Reactor Chemistry
This radiochemistry course is designed to provide PTNR students with the appropriate knowledge required to understand the chemistry associated with nuclear materials and the interaction with their surroundings. The initial part of the course will cover the following key chemistry principles:
- Atomic structure and properties:
- Electronic configurations
- Atomic numbers and the periodic table
- Atomic properties and periodicity including ionization energies
- Periodic trends
- Oxidation and Reduction
- Bonding and structures of inorganic solids
- Chemistry of the actinides
The second part of the course will focus on radio chemistry and nuclear chemistry, Nuclei, isotopes and isotope separation, Physicochemical differences for isotopes, Isotope effects in chemistry, Solvent extraction separations.
Semester 2, contact hours - 11.
Introduction to control theory: Laplace transforms, Bode and Nyquist diagrams, Routh criterion, Root Locus methods. Applications to reactors: delayed neutrons, reactor kinetics equations for one-velocity point model and transport theory. Response to reactivity steps, power transfer function.
Linearised reactivity feedback: temperature and void effects, boiling water reactor stability. Fission product poisoning, effects on stability, burnable poisons. Self-limiting, super-prompt reactor excursions, fast and thermal systems. Introduction to stochastic control theory. System optimisation and methods of measurement. Reactor transfer functions from noise analysis.
Semesters 1, 2 and summer term, contact hours - 26.
Reactor Systems I&II & Safety Analysis
- Economics of nuclear power: Breakdown of cost and factors affecting it. Comparison with fossil-fuelled plant. World-wide distribution of the reactors and their relative advantages and disadvantages. Possible future developments.
- Graphite moderated reactors: Magnox reactors: Factors affecting choice of fuel, cladding and moderator. Materials and safety factors affecting temperature and performance. Overall factors affecting thermal efficiency. Emergency shut-down and core-cooling plant. Effects of depressurisation accident. Consequences of on-load refuelling. Steel oxidation.
- AGRs: Ways in which this reactor overcomes the limitations of Magnox systems. Differences in design arising from different fuel and higher gas temperatures. Fuel and moderator design and performance; radiolysis and graphite corrosion. Emergency shut-down systems.
- HTGRs: Construction of fuel microspheres and core layout. Fission product retention. Temperature limitations and possible use for process heat plant.
- Water moderated reactors: PWRs: Main features of plant, including layout and containment. Reactivity control with chemical shims, the Chemical and Volume Control System. Power defect and load-following. Consideration of safety of thick steel vessels. Auxiliary shut-down and emergency corecooling plant. Loss-of-coolant accidents. Radiolysis and zirconium interaction with water. The Sizewell B design. Use of MOX in PWR plant.
- BWRs: Differences between PWR and BWR systems and effects on performance and safety e.g. effect of steam on design and operation. Emergency core cooling. Primary containment philosophy.
- CANDU and SGHWR: Similarities and differences between the two systems. Advantages of use of D2O and of pressure tube designs; fabrication and problems of pressure tubes. Emergency core cooling. Uranium utilisation. Other reactor systems: Graphite-moderated but water cooled reactors (e.g. the RBMK, Chernobyl type). Mixed oxide fuels.
- Fast breeder reactors: Possible breeding cycles. Factors affecting choice of fuel and coolant. Design features arising from use of liquid sodium. Effect of sodium voiding. Overall plant layout. Special instrumentation. Doubling time and breeding ratio.
- Reactor safety: Methodology of event-tree and fault-tree analysis. Statistical data on component failure rates. Safety related engineering studies. The role of the Nuclear Installations Inspectorate and concepts of Tolerability of Risk. Problem of human intervention.
- Dispersion analysis; effects of weather, siting and population distribution. Role of instrumentation; redundant logic and fail-safe systems. Discussion of main features and conclusions of the Rasmussen Report. Analysis of the Three Mile Island and Chernobyl accidents.
Semesters 1 and 2, contact hours - 6 for RS I and 22 for RS II.