Fall 2017 Quiz 5: Separations, In-reactor chemistry, application of nuclear material, and nuclear forensics

Use the lecture notes, chart of the nuclides, table of the isotopes, and web links to answer the following questions.  The quiz is assigned 6 December 17, 1st due date 13 December 17, 2nd due date 16 December 17.  There will be a class discussion on the quiz on Friday 8 December at 0900 in the 1st floor conference room.

Fall 2017: RDCH 702 Lecture 12: Nuclear Forensics

This lecture covers the utilization of radionuclide properties to determine origin, age, used, and other properties of nuclear material. These isotope properties are defined as signatures of nuclear material, and include concentrations, relative amounts, and ratios. Specific details are provided on forensic signatures related to Pu and actinide isotopics. The signatures arising from reactors, separations, and post-detonation are included. For plutonium production these signatures include reactor power, reactor type, time of irradiation, separation method, and time since separation. The signatures include plutonium isotopic mass ratios, plutonium isotopic activity ratios, and transplutonium isotope ratios. Separation signatures include evaluation of Zr, Tc, Ru, and the lanthanides, with examples using Nd isotopics. Alloys of actinide metals as signatures is also presented. The lecture is assigned on 4 December and due 9 December.

Fall 2017 RDCH 702 Lecture 11: Application of Nuclear Material

The lecture provides examples of the use of radioactive isotopes. The methods used for isotope production are discussed. The difference between isotope production by accelerators and reactors is highlighted. Reactor isotope products are primarily neutron rich; while accelerator produced isotopes tend to be neutron poor. Isotopes used in the generation of neutrons are provided. These neutron generating sources are small with a relatively low neutron generating rate. They are used in element and compound identification. Examples of isotopes used as ionization sources are provided. The discussion focuses on the use of ²⁴¹Am for smoke detection and ⁶³Ni for explosives detection. The importance of ²³⁸Pu as a heat source is provided, with examples given for space exploration. A number of isotopes used in radiopharmaceuticals are introduced. Comparisons are given for diagnostic and therapeutic radiopharmaceuticals.  The lecture is assigned 29 November and due 4 December.

Fall 2017: RDCH 702 Lecture 10 In reactor chemistry

This lecture describes the chemistry of actinides and fission products in reactors, primarily focusing on phases formed in nuclear fuel. An overview of reactors is provided.  The fission process is reviewed and fuel burnup discussed. Determining fission product and actinide concentration to assess burnup is introduced. The variation of fission product and actinide concentration with burnup and initial fuel composition is provided. Axial and radial distribution of activity, fission products, and actinides is discussed, highlighting the role of neutron flux and energies on the distribution. Conditions necessary for the formation of separate phases in UO₂ are shown for perovskite and metallic phases, emphasizing the role of oxygen in the process. The behavior of fission products can be grouped into 4 areas: volatile species, metallic precipitates, oxide precipitates, and solid solutions.   The lecture is in class on Friday 1 December.  The PDF quiz is due 5 December.

Fall 2017: RDCH 702 Lecture 9 Separations

A number of different separation methods for radionuclides, with an emphasis on actinides, are presented. Solvent extraction, ion exchange, electrochemical, volatility and ionic liquid methods are discussed. The fundamental concepts are provided with specific examples on the nuclear fuel cycle. Ideas and concepts for advanced separations are given. Details are provided for the different separation routes discussed. The PUREX process is described. Examples are given for TRUEX and TALSPEAK separations. Specific examples for actinide separation are provided.