Determination of tritium breeding ratio in a PbLi spherical blanket by leakage neutron spectra

AbstractA new integrated method was proposed to determine the tritium breeding ratio from the 6Li(n, α)T reaction (T6) in a spherical assembly simply simulating the fusion reactor blanket with neutron multiplier. T6 can be derived from the neutron balance by measuring the total leakage neutrons from the assembly and the multiplier. To verify this method, a trial experiment has been made by using a D—T neutron source and a natural lithium sphere with an inner lead multiplier zone. T6 could be determined successfully by the leakage and the multiplication, both of which were obtained from the measurement of leakage neutron spectra. The accuracy of the T6 derivation was discussed in comparison with the neutron transport calculations using the evaluated nuclear data files of JENDL-3T and ENDF/B-IV. Adequacy of the cross section values and the neutron emission spectra for Pb(n, 2n) reaction was also discussed because of the disagreement between the measured and calculated leakage spectra.