Thursday, July 23, 2015

Summer 2015: Quiz 5: Survey

Please respond to Quiz 5, which is a course survey.  Responses from the survey have been used to modify and improve the course in the past.  Please return quiz 5 prior to your departure.

Sunday, July 19, 2015

Summer 2015: Quiz 4

Quiz 4                                                                                                                           
Assigned: 19-Jul-15                                     
Due: 22-Jul-15
2nd submission: 26-Jul-15
Lecture 14:  Pu Chemistry
Lecture 15:  Am and Cm Chemistry
Fast Reactors and Gas-cooled Reactors
Fuel design and History of Reprocessing

Lecture 16:  In-reactor Chemistry

Use lecture notes, textbooks, Chart of the Nuclides, Table of the Isotopes, and web pages.   Show your work or references on a separate electronic submission with the subject line:  Quiz 4 “your last name” work.  Use the PDF form to submit your answers.

Wednesday, July 15, 2015

Summer 2015: 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.

Wednesday, July 8, 2015

Summer 2015: 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 and248Cm, 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. 

Monday, July 6, 2015

Summer 2015: Quiz 3

Assigned: 7-Jul-15                                                                          
Due: 13-Jul-15
2nd submission: 17-Jul-15

Quiz 3 covers the following topics:
Lecture 9:  Nuclear Reactions
Lecture 10:  Speciation
Lecture 11:  Uranium Chemistry
Lecture 12:  Technetium Chemistry
Lecture 13:  Neptunium Chemistry
Nuclear Forensics (Beach Lecture)


Use lecture notes, textbooks, Chart of the Nuclides, Table of the Isotopes, and web pages.   Show your work or references on a separate electronic submission with the subject line:  Quiz 3 “your last name” work..

Sunday, July 5, 2015

Summer 2015: Lecture 14 Plutonium Chemistry

This lecture provides basic information on the chemistry of plutonium in three parts. 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, including 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 the various nature of plutonium chemistry in the solution phase, as colloids, and solid phase. The non-aqueous chemistry of plutonium is described and related to electronic structure. 

Saturday, July 4, 2015

Summer 2015: Lecture 13 Neptunium Chemistry

Neptunium chemistry is covered in this lecture. 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.

Thursday, July 2, 2015

Summer 2015: Lecture 11 Uranium and the fuel cycle

This lecture is in two parts. Uranium chemistry is covered in this lecture with an emphasis on separations and synthesis for the nuclear fuel cycle. Uranium is introduced with an overview of its chemistry for the 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. 

Wednesday, July 1, 2015

Summer 2015: Lecture 10 Speciation

This lecture covers fundamentals of chemical kinetics thermodynamics, mainly as a review. Emphasis of the lectures is applied to information useful for speciation modeling. Equilibrium constants are discussed. The role of chemical activity is provided. Calculations and models for speciation are presented. Equilibrium modeling using EXCEL and the program CHESS are presented. Solubility calculations are provides, with examples for the uranium system.