STP956: Measurements of 10B(n,He) Reaction Rates in a Mockup Control Rod in ZPPR

    Brumbach, SB
    Physicist and physicist, Argonne National Laboratory, Idaho Falls, ID

    Collins, PJ
    Physicist and physicist, Argonne National Laboratory, Idaho Falls, ID

    Oliver, BM
    Staff scientist, Rockwell International, Canoga Park, CA

    Pages: 12    Published: Jan 1987


    Abstract

    Results are reported for 10B(n,He) reaction rate measurements inside B4C pellets contained in a mockup control rod in the Zero Power Plutonium Reactor (ZPPR). The helium accumulation fluence monitor (HAFM) technique was used, with absolute amounts of helium determined by isotope-dilution mass spectrometry. Rates of 235U fission were measured in foils irradiated between B4C pellets. Fission rate measurements used gamma ray counting techniques. Both helium production and fission rates were calculated using three-dimensional nodal transport methods. Measured helium production rates decreased about 18% within the first 63 mm of the pins, and decreased 10 to 12% going from outer to inner pins in this small, 16-pin control assembly. The calculated and measured reaction rate profiles agreed within the 1 to 2% measurement uncertainties. Helium production rates were underestimated by calculations by about 8%.

    Keywords:

    boron carbide, helium production, boron capture, control rod damage, fast reactors, reaction rate measurements


    Paper ID: STP25692S

    Committee/Subcommittee: E10.08

    DOI: 10.1520/STP25692S


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