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Information of secondary neutron source in French PWR

  1. Nov 7, 2016 #1
    The specific information of secondary neutron source in French 1300MWe and N4 PWRs are needed, e.g.the total mass of Sb-Be in core and the thickness of Sb-Be cladding with stainless steel, but unfornately I couldn't find any useful information in google in English. I guess some informatio could be found in google in Fench,Could anyone help me to search information? Thank you very much for any help.
  2. jcsd
  3. Nov 11, 2016 #2


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    The following article contains some data, e.g., density of Sb and Be, and SS, but unfortunately the design is for a 16x16 OP-1400 fuel design (similar to CE System 80).

    Typically there are 4 source rods per assembly in two assemblies, or sometimes four assemblies.

    For a typical 17x17 core, with a core height of 3.66 m, there is a diagram of an Sb-Be secondary source here

    The length of Sb-Be is 88 inches (223.5 cm). The stainless steel (SS 304 or 316) cladding outer diameter is approximately 0.968 cm, and the wall thickness is approximately 0.057 cm. It's possible that a longer Sb-Be would be used for the 4.27 m core, e.g., 260 cm.
  4. Nov 12, 2016 #3
    Thank you very much for providing so much useful information and document.
    There are some clues about configuration of Westinghouse-type secondary sources assembly and the most univesal configuration contains 4 source rod, which could been foungd at Page 25/56 in document Integrity of Neutron-Absorbing Components of LWR Fuel Systems.pdf http://www.osti.gov/scitech/servlets/purl/5980553/.
    However, there are seldom information of secondary source in French 1300MW and N4 unit in web. It may get some clues if one seach in French.
    As I know, more Sb-Be rods with shorter actived length are used for about 4.2m reactor core in EPR, but not more longer source rod.
  5. Nov 12, 2016 #4


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    The description of the Westinghouse AP-1000 (~4.2 m core) has the following as some information on the secondary source rods.


    The primary and secondary source rods both use the same cladding material as the absorber rods.
    The secondary source rods contain antimony-beryllium pellets stacked to a height of
    approximately 88 inches [223.5 cm]. The primary source rods contain capsules of californium (plutonium beryllium
    possible alternate) source material and alumina spacers to position the source material
    within the cladding. The rods in each assembly are fastened at the top end to a hold-down

    The other structural members, except for the springs, are constructed of Type 304 stainless steel.
    The springs exposed to the reactor coolant are nickel-chromium-iron Alloy 718.

    See Figure 4.2-15 Secondary Source Assembly

    There is a conflict between this figure Ref: 97.0 absorber length [246.4 cm] and the 88 inches [223.5 cm] in the text. The figure is probably correct, and that would likely apply to the 4.2 m cores of the CPY and N4/P4 plants.

    There may be some information here
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