1

27 - 725Materials for Nuclear Energy

L1: Introduction

Tony (A.D.) Rollett, Carnegie Mellon University

Spring 2019

Updated 15th Jan. ‘19

2

Microstructure-Properties Relationships

Microstructure Properties

ProcessingPerformance

Design

3

Course Objective• Students in this course will learn about Materials that are used in

nuclear energy systems. The course covers the full range of materials that are relevant to nuclear energy with a focus on materials subject to irradiation (glasses, steels, nickel alloys, and zirconium alloys). Applications of materials include waste storage, reactor vessels, turbines, pumps, piping, and fuel elements. For the materials used in each application, the selection and performance criteria are considered, as well as the underlying structure, thermodynamic, and kinetic processes that influence materials properties. The effects of irradiation on materials properties and performance will be examined; hence radiation damage is the primary topic to be discussed. Key properties include strength, fracture toughness and corrosion resistance. Many of these properties continue to change over the long service periods expected of components. In addition to lectures and homeworks, each student will complete a detailed case study (aka term paper) in which they examine a particular material and application.

• The objective of this course is to provide you with an understanding of the materials science that explains and illuminates the wide range of materials used for nuclear energy production.

4

People

• The development of the field is greatly indebted to Glasstone, Wigner, Kinchin, Pease, Lindhard, Zinkle, Was, among many others.

Samuel Glasstone: Nuclear Reactor Engineering

5

Details• All relevant materials for the course are published either on the

Blackboard website or in the Box folder for 27-725.• CA for 725: Dino Wu, zihengw@andrew.cmu.edu.• Homework each week, posted on website.• Quizzes? Discuss in class.• Mid-course exam = 11th Feb. – proposed• No final exam• Student presentations, 5 minutes each, based on Term Paper;

probably on Feb. 25th to allow time for finalizing your paper.• Grades:

– A: > 90%– B: > 80%– C: > 70%– D: > 60%– Weighting: – Mid-term, 25%; Term Paper 40%; Homeworks 35%.

6

Topics/ Lecture List• Nuclear Reactions• Cross sections• Radiation Damage• Nuclear Fuel• Cladding• Corrosion• Reactor Design

• Pressure Vessel Steels• Nickel alloys• Stainless Steels• Zirconium alloys• Welding• Glasses, Boron• Public policy, regulatory

issues, basic economics

See the syllabus for a more detailed list of topics and dates.

7

Books, References• Gary S. Was, Fundamentals of Radiation Materials Science. Metals and

Alloys, ISBN 3540494715, Springer Verlag, 2007. Recommended as the most complete description of the effects of radiation on materials. It is, however, metals-centric and has little to say about nuclear fuel.

• M.A. Nastasi, J.W. Mayer, J.K. Hirvonen, Ion-solid Interactions, Cambridge University Press, 2004.

• Iaon Ursu, Physics and technology of nuclear materials, ISBN: 0080326013, call no. TK9185 .U7713, 1985.

• Charles O. Smith, Nuclear reactor materials, Addison-Wesley, 1967; call number: 621.483 S64N.

• B. R. T. Frost and M. B. Waldron, Nuclear Reactor Materials, Temple Press Limited, London, 1959; call number: 621.4833 F93N.

• L. Wang Lau , Elements of nuclear reactor engineering, Gordon & Breach Science Pub., 1974; call number: 621.483 L36E.

• D.R. Olander, Fundamental Aspects of Nuclear Reactor Fuel Elements, NTIS, 1976.

• B.M. Ma. Nuclear Reactor Materials and Applications, Van Nostrand Reinhold Company, NY, 1983.

• J.T. Adrian Roberts. Structural Materials in Nuclear Power Systems, Plenum Press, NY, 1981.

Office Hours?

• I do not keep regular office hours.• I keep an open door policy.• Best to email me to ask for a specific

time, and include your question(s) so that I have some idea of what help you need.

8

Teaching Approach

• Complete lecture notes embodied in the slides.

• Chalk & talk for each lecture.• Frequent questions to students about

the material being discussed.• Students are expected to have read

through the lecture notes before each lecture.

9

1-page Materials Overview10

• Pressure vessels in PWR and BWR reactors are made from a low alloy ferritic steel; the main issue is long-term increase in the ductile-to-brittle transition temperature (DBTT) as a consequence of irradiation.

• Internal structures are made from a mix of stainless steel and Ni alloys, which have better high temperature properties and resistance to corrosion. The choice of material depends on service temperature, stress and corrosion potential. Corrosion of pipes, headers etc. is the most common cause of problems.

• Zirconium alloys are used to contain the nuclear fuel. They have low capture cross-sections for neutrons and therefore are relatively radiation resistant, as well as having good high temperature strength.

• Nuclear fuel is made from UO2 in power reactors. This has moderate resistance to radiation damage. Notably, the accumulation of fission products (esp. gases) leads to gas bubbles, swelling and cracking of the fuel, which limits burn-up and the useful life of the fuel.

11

Summary• Materials choice is strongly affected by the response to

radiation damage in a nuclear reactor. It is also strongly influenced, however, by cost, and so each specific component represents a compromise between cost and performance.

• Many properties are strongly affected by radiation damage. The Ductile-to-Brittle-Transition Temperature (DBTT) in steels, for example, is typically raised by irradiation, raising the risk of embrittlement of a pressure vessel.

• Different types of materials vary widely in their resistance to radiation damage. High atomic numbers, in general, accumulate damage less quickly. Thus metals have the best resistance as compared to ceramics or polymers.

12

Supplemental Slides

• [none]