Fall 2014: CHEM 312 Lecture 16 In Reactor Chemistry

This lecture describes the chemistry of actinides and fission products in reactors, primarily focusing on phases formed in nuclear fuel. 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.

Fall 2014: CHEM 312 Lecture 15 Americium and Curium Chemistry

This lecture introduces the chemistry of americium and curium. Both elements are discussed due to their similar chemical behavior, particularly in separations. However, important differences in their chemistry are highlighted. For americium pentavalent and hexavalent species are achievable. For curium, its unique fluorescence properties are highlighted. The nuclear properties of americium and curium isotopes are provided. Isotope production focus on those formed from multiple neutron capture. These isotopes, ²⁴¹Am, ²⁴³Am, ²⁴⁴Cm and ²⁴⁸Cm, are used to explore americium and curium chemistry. The basic solution chemistry is described, along with implications for fuel cycle separations. Methods for the separation of americium and curium are provided, including solvent extractions, anion exchange, precipitation, and molten salt techniques. Synthesis and characterization of americium and curium metals, alloys, and compounds are provided, with emphasis placed on those compounds of importance to the nuclear fuel cycle. The non-aqueous and coordination chemistry of these elements are introduced. The limited available data offers an avenue for novel explorations and future research directions. 

Fall 2014: CHEM 312 Lecture 14 Plutonium Chemistry

This lecture provides basic information on the chemistry of plutonium. Discussion on the nuclear properties of ²³⁸Pu and ²³⁹Pu are included. Environmental concentrations of plutonium, including ²⁴⁴Pu and naturally produced ²³⁹Pu, are discussed. Large scale plutonium separations are presented, emphasizing the PUREX process. The use of volatility and ion exchange as plutonium separation techniques are also given. The synthesis and properties are metallic plutonium are described in detail. An review of metal preparation methods are provided, including the plutonium-gallium phase diagram. The physical properties of plutonium metal are given and discussed. The solution chemistry of plutonium is depicted though coordination and spectroscopy as a function of oxidation state. Examples are provided on various nature of plutonium chemistry in the tributylphosphate-nitric acid system and colloids. The non-aqueous chemistry of plutonium is described and related to electronic structure. 

Fall 2014: CHEM 312, Quiz 3

Quiz 3

Assigned 11 November 14

1^st Answers Due: 20 November 2014

2^nd Answers Due 25 November 2014                                                                      

Lecture 8: Nuclear Structure and Models

Lecture 9: Nuclear Reactions

Lecture 10: Radiation Interaction

Lecture 11: Speciation

Lecture 12: Uranium Chemistry

Use lecture notes, textbooks, Chart of the Nuclides, Table of the Isotopes, and web pages.   Show your work or references on a separate page.  The first sent of answers are due 20 November 2014.  The answer sheet will be posted on 20 November 2014.  You can use the answer sheet to correct any missed question.  Work will need to be included with any changed answers.

Please post any questions to the blog.  We can organize a skype conference on Thursday 20 November and Tuesday 25 November.

Fall 2014: CHEM 312 Lecture 13 Neptunium Chemistry

Nuclear properties and synthesis of neptunium are described, with emphasis placed on the isotopes ^235-239Np. The synthesis and properties of neptunium metal, alloys, and intermetallic compounds are introduced. The lecture describes neptunium compound synthesis, with resulting thermodynamic and structural properties provided. Neptunium organometallic and coordination compounds are also presented. Information on neptunium solution speciation, redox, and spectroscopy is given, with trends based on oxidation state examined. A presentation of analytical methods useful in neptunium chemistry, including Mössbauer spectroscopy, concludes the lecture. Comparisons are made with uranium chemistry to provide trends in the actinides.

Fall 2014: CHEM 312 Lecture 12: Uranium Chemistry

Uranium chemistry is covered in this lecture with an emphasis on separations and synthesis for the nuclear fuel cycle. The solution chemistry of uranium is explored, focusing on uranyl. The molecular orbital of uranium is described. Separation of uranium by solvent extraction and ion exchange is presented. The enrichment of uranium from the uranium hexafluoride species is discussed, including diffusion, centrifuge, and laser methods. Oxide species of uranium are presented. Due to its potential as a nuclear fuel, the synthesis and properties of uranium metal and alloys are described in detail. With three different phase, the uranium metal exhibits more complex electronic behavior than the metals of the lighter actinides, a trend that continues to plutonium metal.