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Homework Help: Breeding Ratio of thorium fuel cycle

  1. Mar 29, 2010 #1
    1. The problem statement, all variables and given/known data
    A breeder reactor is designed to work on a thorium fuel cycle. If the reactor generates a constant thermal power of 2.5GW and a production rate of 233U is 52kg per year. Find the breeding Ratio

    [You may assume the capture to fission ratio of 233U is 0.09 and the energy released per fission is 197.9Mev.]

    2. Relevant equations
    Breeding Ratio= number of fissile nuclei produced/ number of fissile nuclei consumed

    3. The attempt at a solution
    I really don't know how to go about solving this problem.
    I would assume that the capture to fission ratio is important.

    The fission of one atom of U-233 generates 197.9 MeV = 3.171 × 10−11 J, i.e. 19.09 TJ/mol = 81.95 TJ/kg.
    Then multiply by 0.91 and calculate the energy from fission of 52kg.

    81.95 TJ/kg x 52kg x 0.91=3.88x1015J per year

    Also reactor produces 2.5GW so I can see this is also really important but get the feeling I am missing something simple as this is the 1st question on a past paper.

    Any help really appreciated

    Last edited: Mar 29, 2010
  2. jcsd
  3. Mar 31, 2010 #2
    ha... im stuck too lewis i swear this wasn't in his notes...

    rate of production of new fuel = G w P = 52kg

    G = C - 1

    where C is the breeding ratio...

    strugling to find w (think its to do with the 200 MeV) but i think its simpler than ur calculations
    Last edited: Mar 31, 2010
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