Lecture 1: Introduction Nuclear Forensics and the Fuel Cycle

1. Lecture 1: IntroductionNuclear Forensics and the Fuel Cycle • Readings: • Nuclear Forensics Analysis: Chapter 1 Introduction • Class organization • Outcomes • Grading • Introduction • What is nuclear forensics • Nuclear material • Types of material • Critical masses • Device development • Forensic goals

2. Introduction • Course objectives • Understand and comprehend technical aspects of nuclear forensics • Highlight role of radiochemistry in nuclear forensics • Apply technical aspects to the nuclear fuel cycle • Course will emphasize the role of nuclear forensics in the nuclear fuel cycle • Evaluate available tools • Assess applications and limitations

3. Course overview • Course topics • Basics of radiochemistry for nuclear forensics • Role of applications in nuclear forensics • Chemistry and physics involved in forensics • Principles of devices • Sampling • Laboratory techniques • Application of signatures • Signatures from the fuel cycle • Textbooks and published literature are used a reading material • Moody, Hutcheon, Grant: Nuclear Forensic Analysis • http://radchem.nevada.edu/classes/forfuel/index.htm

4. Outcomes • Understand, utilize, and apply radiochemistry to nuclear forensics • Bring chart of nuclide to class • Fission • Growth and decay • Understand how signatures can arise from applications • Different aspects of the fuel cycle • Utilization and treatment of material • Understand the basic principles of devices • Types of devices • Expected signatures • Understand types of signatures available from analysis • Chronometry • Isotopics • Standard

5. Outcomes • Comprehend role of sample collection in nuclear forensics • Types of samples available • Understand differ laboratory methods for nuclear forensics • Isotopic analysis • Microscopy • Understand how signatures are used • Determining source and attribution

6. Grading (nominal) • Homework (15 %) • Based upon presented information • Two comprehensive quizzes (35% each) • Based on topic covered in lecture and homework • Class participation (15 %) • Be prepared for discussion • Goal of quizzes is material comprehension • Nature of comprehensive quizzes • Take home • Lead to ideas for proposal

7. Outline: Lectures

8. Outline: Lectures

9. Introduction • What is nuclear forensics? • A number of different views exist • Evidence, analysis • Input into attribution • Focus on tools • Nuclear Materials • Material in devices • Fissile isotopes (special nuclear material) • Enriched in 233U or 235U • 235U level can define material (LEU, HEU) • Oralloy 93.5% 235U • Containing any isotopes 238-242Pu • Weapons grade 93 % 239Pu • Reactor grade 8% < 240Pu • MOX 60 % 239Pu, 25 % 240Pu

10. Nuclear Material • Other nuclear material • 237Np • high energy neutrons for fission • Protected material under IAEA • 241Am • 252Cf • 6Li, 2H, 3H • Source material • Th and U • Identify origin and handling of associated material

11. Critical masses • 1 kg of fissile material releases 17 kt TNT equivalent • Minimum quantity of fissile material for nuclear explosion is critical mass • Estimate volume of critical mass for 235U and 239Pu

12. Plutonium is a unique element in exhibiting six different crystallographic phases at ambient pressure (it has a seventh phase under pressure). In addition, unlike most metals, plutonium contracts on melting. Transformations to different crystal structures occur readily and are accompanied by very large volume changes. By comparison, aluminum’s behavior is predictable and uneventful. It expands monotonically on heating in the solid phase, and it also expands on melting. The dashed lines show that thermal contraction on cooling the liquid (L) phase of plutonium extrapolates to that of the β-phase; the thermal contraction on cooling the ε-phase extrapolates to that of the γ-phase.

13. Phase never observed, slow kinetics

14. Fissile and fertile material • Fissile material • Material that can sustain chain reaction • Fertile materials • Source material that can create fissile material • 232Th, 238U • Enrichment of U • Gas, electromagnetic separation • Related to power production and reactor type • How can these be different? • Fast, thermal, CANDU • 1 GWe burns about 1 ton of fissile material annually • 200 kg of Pu produced • about 70 t of Puannually formed in reactor worldwide

15. Device development • Manhattan project to Cold War • Little Boy, U device • Total mass 4100 kg • 84 % enriched 235U • 1 % of U fissioned, 13 kt yield • Fat Man, Pu device • 6 kg, 95 % < 239Pu • Total mass 4900 kg • 20 % efficient, 21 kt yield

16. Device development • Cold war • Improved design, fission yield to 500 kt • Blast influence 125 km2 • http://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html • Fusion with DT or 6LiD • Up to 60 Mt yield • Improved explosive, Ga-Pu alloys • Extensive testing and evaluation • US produced about 100 t 239Pu and 994 t HEU

17. Treaties • Control of weapons based on treaties • Between declared nuclear power • Usage of fission for power • 100 tons surplus 239Pu in each US and Russian inventory • Nuclear smuggling • Range of material

18. Forensic goals • Determine attributes of material • Where produced • What is it • Transport route • Legal and safety issues • Traditional forensics • Fingerprints, DNA, pollen • Source and route • Source from SNM • Time since separation • Relate to nuclear fuel cycle

19. Topic review • Discuss nuclear forensics • Why does it mean different things to different groups • What are the different types of nuclear material • Types of material • Critical masses • Production methods and sources • Device development • How does this influence forensics • Define forensic goals

20. Study Questions • What is Special Nuclear Material? • What is a critical mass? • Include volume analysis • Define nuclear forensics • What are the goals of nuclear forensics?

21. Pop Quiz • What are the course outcomes?