Tuesday, February 27, 2018

CHEM 418 Nuclear Chemistry, Winter 2018: Lecture 16 Nuclear Reactors and In-reactor chemistry

This lecture provides an overview of nuclear reactors and describes the chemistry of actinides and fission products in reactors.  A broad overview of nuclear reactors is provided.  The essential components of a reactor, fuel, cladding, coolant, and moderators, are described.  Characteristics of reactor materials and nuclear fuels are given.  A summary of reactor types, generally classified on coolant properties, is provided.  The chemistry of nuclear fuel is provided, with an emphasis placed on understanding the 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. The lecture is in two parts.  Part 1 is length is 36 minutes, part 2 is 32 minutes.
The lecture is assigned on Saturday 24 February 2018 and due Wednesday 7 March 2018. 

38 comments:

  1. This comment has been removed by the author.

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  2. Lecture 16 watched but the quiz hasn't been posted yet. Will it be posted soon?

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  3. lecture 16 has been watched and the quiz has been sent through email

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    Replies
    1. Dalton, what quiz did you send? I can't find a recently posted one.

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  4. Lecture viewed, but quiz is not available?

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  5. Lecture 16 was viewed, will comment again when the quiz is available.

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  6. Lecture 16 viewed, I also could not find the quiz

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  7. Lecture 16 viewed, but no quiz available

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  8. I have viewed lecture 16 and will comment again after the quiz is available.

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  9. Lecture 16 viewed, I also could not find the quiz.

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  10. Lecture Viewed. There is no link to the quiz in the assignment and I coudln't find an updated one in the files.

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  11. I viewed Lecture 16. Also, I submitted the old quiz 16 because I couldn't find the new one.

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  12. I have submitted a completed old version of quiz 16 by email, but I will also complete the updated quiz 16 once it has been posted.

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  13. I viewed the lecture however no quiz is available

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  14. Many thanks for the comments. The quiz is now available with an extended due date.

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  15. I have submitted the new available quiz for lecture 16

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  16. PDF Quiz was submitted via email.

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  17. Lecture viewed and pdf quiz submitted via email

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  18. PDF quiz is now submitted on canvas.

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  19. Lecture viewed and quiz submitted.

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  20. I have submitted the new quiz 16 by email.

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  21. How do we determine the efficiency of a moderator? You mention that 12C requires 114 collisions vs 18 for 1P, but I coudn't find anything like that for 2P in the lecture slides. What exactly are you looking for in the answer? Thanks.

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    Replies
    1. The question is related to the relative interactions with neutrons. You can compare the neutron absorbance for 2H and 12C compared to 1H. Examine the ratios and you will see that 1H has a much higher probability to interact with a neutron. If you do not have 1H but use 2H or 12C, the neutron will have a longer lifetime. This will increase the probability the neutron will interact with 235U, causing fission.

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    2. Ok got it. Thanks!

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  22. Quiz is submitted Ryan Cheung.

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  23. lecture viewed and quiz submitted

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  24. quiz emailed and lecture viewed

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  25. Lecture reviewed and quiz submitted through canvas

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  26. the lecture has been viewed, and the quiz has been sent. Please ignore the quiz i sent you before, it was the old one.

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  27. Lecture was reviewed and the quiz was submitted on canvas.

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  28. Lecture viewed, quiz submitted.

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  29. Lecture Viewed and Quiz Submitted

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  30. Quiz submitted via email

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  31. Lecture Viewed and Quiz Submitted

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  32. Lecture done, quiz done. Thanks again for the help.

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