%A"Sato, Satoshi" %A"Seki, Yasushi" %A"Takatsu, Hideyuki" %A"Zimin, S [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment]" %A"Maki, Koichi" %A"Kuroda, Toshimasa" %D1992 %I; Japan Atomic Energy Research Inst., Tokyo (Japan) %2 %J[] %K70 PLASMA PHYSICS AND FUSION TECHNOLOGY, HETEROGENEOUS EFFECTS, SHIELDING, SUPERCONDUCTING MAGNETS, THERMONUCLEAR REACTORS, BREEDING BLANKETS, NEUTRONS, TOKAMAK DEVICES, SHIELDING MATERIALS, STAINLESS STEELS, WATER, 700480, COMPONENT DEVELOPMENT, MATERIALS STUDIES %PMedium: X; Size: 61 p. %THeterogeneous effects on shielding characteristics in fusion reactor neutronics calculations %XHeterogeneous effects in shielding calculations were evaluated in terms of shielding characteristics of a blanket/shield structure to superconducting magnets (SCM) of a fusion reactor. A wide range of parameters was examined such as thicknesses of individual steel/water layers composing shield region and thicknesses of shield and blanket regions and the following results were obtained. With a constant thickness of a shield region of 70 cm, the heterogeneous effects increased with the thickness of individual steel/water layers in shield region. In the case the thicknesses of individual steel/water layers were smaller than 2 cm/5 mm, the heterogeneous effects both in the coil case and in the winding pack of SCM were less than 3 %. In the case the thicknesses of steel/water layers were 12 cm/3 cm, the heterogeneous effects in the winding pack and in the coil case were 20 % and 9 %, respectively. The heterogeneous effects both in the coil case and in the winding pack increased with the total thickness of the shield region, and saturated at 18 % and 13 %, respectively, under the constant thickness of individual steel/water layers in the shield region of 8 cm/2 cm. The heterogeneous effects showed a negligible dependence on the thickness of the blanket region and on addition of supplemental shield such as boron carbide and lead layers. The heterogeneous effects were examined for the inboard blanket of an International Thermonuclear Experimental Reactor (ITER) based on its conceptual design. The heterogeneous effects of nuclear heating rates in the coil case and in the winding pack were found to be 27 % and 29 %, respectively, and to be within a safety factor of 30 % for an error of modeling assumed in the conceptual design of the ITER. (author). %0Technical Report %NJAERI-M-92-093;Other: ON: DE93753285; TRN: JP9211206 %1 %CJapan %Rhttps://doi.org/ Other: ON: DE93753285; TRN: JP9211206 JPN %GJapanese