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Why Was Diffusion Selected for Eurodif?

  1. Jul 19, 2017 #1
    The Eurodif gaseous diffusion plant required so much electricity that three of the four 955 megawatt nuclear reactors at Tricastin were allocated to meet to its power demands. In fact the Eurodif plant was such a large industrial consumer that the reactors were were built close by to minimize transmission losses, and as of 2012 it was consuming the equivalent of 4.5% of France's total electrical demand. After Eurodif switched to using gas centrifuge technology at least two of the reactors were freed up to provide power to other customers.

    Nuclear power plants were less expensive in the 1970s and electricity demand was rapidly growing at that time, so building a massive nuclear power station to meet the needs of a single industrial consumer might not have seemed as radical at the time. For example, the Kingston coal fired power station was built to help meet the needs of Oak Ridge, and the Midland cogeneration plant in the United States was originally going to be a dual unit nuclear power station (it was completed as a natural gas plant) to provide heat and power to nearby chemical factories. Still, 3.6 gigawatts is a massive amount of power. Gas centrifuge technology was also undergoing rapid development for Pakistan's nuclear weapons program, and many of the components were imported from European suppliers.

    Did the Eurodif project ever consider alternative enrichment technologies such as gas centrifuges or chemical enrichment (another French enrichment technology)? Furthermore, since the 1970s was a time of growth in nuclear power were there concerns that newer enrichment technologies might overtake Eurodif?
  2. jcsd
  3. Jul 19, 2017 #2


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    This IAEA document describes the state of the art in enrichment by 1977.

    Centrifuge technology was not mature at the time. High strength materials and high speed bearings were necessary.

    On page 48 of the IAEA document:
  4. Jul 19, 2017 #3
    AREVA says Georges Besse I (the gaseous diffusion plant, Georges Besse II is the gas centrifuge replacement) had a total capacity of 10.8 MSWU per year, but only produced 150 MSWU throughout its entire service life. That gives an average output of 4.17 to 4.55 MSWU per year (diffusion ran from 1976 or 1979 to 2012). Was Eurodif massively overbuilt in anticipation of future nuclear fuel demands that never arouse or did Urenco and other firms using gas centrifuge technology eat into its market share in the limited nuclear fuel market that ultimately arouse?

    Also, were the three reactors at Tricastin allocated to Eurodif for its total capacity (in practice resulting in a surplus for the grid due to reduced operations) or just what was necessary to meet the reduced operations that ultimately transpired?

    So at that point in time it was deemed less expensive to use ten times the electrical capacity and go with gaseous diffusion instead of going with centrifuges? Do you know how much of that is due to power plant capacity (especially nuclear) being so inexpensive at the time versus how much of that was due to centrifuges being unreliable?
  5. Jul 20, 2017 #4


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    From the AREVA site referenced: "Located on the Tricastin site, the Georges Besse II plant whose construction was started 3 years ago will eventually be made up of 2 units of enrichment. Thanks to its modular nature it will reach a total production of 7.5 million SWU per year in 2016, 2 years earlier than originally planned.The Georges Besse II plant produced its first SWU in December 2009."

    Gaseous diffusion technology apparently lead centrifuge technology, so GD was selected for industrial scale in the 1970s. I don't know if the George Besse plant was overbuilt, but I suspect it was built with the expectation that Europe would have more nuclear reactors, and such large capital projects are driven by economies of scale. The GB I was in operation when TMI-2 had it's accident, and consequently, plans for additional NPPs were suspended or cancelled. Given that GB I was up and running in 1977, they probably had 30 years of operation in mind for recovery of investment.

    Had centrifuge technology been perfected by the early 1970s, I would imagine that Eurodif would have gone that route. On the other hand, Urenco was able to introduce centrifuge technology in 1982, and the Capenhurst GD plant was shutdown after operating since the early 1950s.

    According to a Wikipedia article, gas centrifuge technology was applied on the industrial scale fairly recently in the US. Prior to that, GD was the predominant technology at 3 sites: Paducah, Portsmouth and K-25.

    The economy of NPPs follows a similar trend. Basically, NPPs have been initially designed for 40 years with an expectation that they would be paid off at 30 years. Now, various plants have life extensions of 20 years, to a 60-year lifetime, and there is some effort to extend life to 80 years. Of course, some plants proved very expensive with substantial cost over-runs following the Browns Ferry fire and TMI-2 accident, which necessitated major design changes to ensure safety.
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