JPS642199U - - Google Patents

Description

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は、本考案が実施された核燃料集合体の
一例を概略的に示す側面図、第１Ａ図は、第１図
の１Ａ―１Ａ線に沿つて、燃料棒を取り除いて支
持グリツドを拡大して示す平面図、第１Ｂ図は、
第１図における領域１Ｂの拡大側面図、第２図は
、第１Ｂ図の―線に沿つて示す断面図、第３
図は、第２図の―線に沿つてリブ断面を示す
断面図、第４図は、第２図の―線に沿つてリ
ブ交点と燃料棒との位置的関係を示す断面図、第
４Ａ図及び第４Ｂ図は、リブ交点のそれぞれ異な
る断面形状を示す断面図、第４Ｃ図は、第４図に
おいて燃料棒が膨張した際のリブ交点と燃料棒と
の位置的関係を示す断面図、第５図は、従来の核
燃料集合体の下部ノズルを示す部分側面図、第６
図は、第５図の―線に沿つて示す断面図、第
７図は、第６図の―線に沿つて冷却材流通孔
と燃料棒との位置的関係を示す断面図である。 １……下部ノズル、１′……上部ノズル、２ａ
……縦リブ、２ｂ……横リブ、２ｃ……リブの交
点、４……中空管（案内管）、５……燃料棒、６
……支持グリツド、６ｃ……開口、１１……冷却
材流通孔、１６……冷却材流通孔、１７……冷却
材流通孔。 Figure 1 is a side view schematically showing an example of a nuclear fuel assembly in which the present invention is implemented, and Figure 1A is an enlarged view of the support grid with fuel rods removed along line 1A-1A in Figure 1. The plan view shown in Figure 1B is as follows.
FIG. 2 is an enlarged side view of region 1B in FIG. 1;
4 is a cross-sectional view showing the rib cross-section along line - in FIG. 2, FIG. 4 is a cross-sectional view showing the positional relationship between the rib intersection and the fuel rod along line - in FIG. 4B and 4B are cross-sectional views showing different cross-sectional shapes of the rib intersections, and FIG. 4C is a cross-sectional view showing the positional relationship between the rib intersections and the fuel rods when the fuel rods are expanded in FIG. FIG. 5 is a partial side view showing the lower nozzle of a conventional nuclear fuel assembly;
5 is a cross-sectional view taken along the line --- in FIG. 5, and FIG. 7 is a cross-sectional view taken along the -- line in FIG. 6, showing the positional relationship between the coolant flow holes and the fuel rods. 1...Lower nozzle, 1'...Upper nozzle, 2a
... Vertical rib, 2b ... Horizontal rib, 2c ... Rib intersection, 4 ... Hollow tube (guide tube), 5 ... Fuel rod, 6
...Support grid, 6c...Opening, 11...Coolant distribution hole, 16...Coolant distribution hole, 17...Coolant distribution hole.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] それぞれ多数の冷却材流通孔を具えた上部ノズ
ルと下部ノズル、前記両ノズル間を連絡し、相互
に平行に配置された複数の中空管、該中空管にそ
の長手方向に間隔をおいて固定された支持グリツ
ド、及び該支持グリツドの各開口に挿通支持され
、相互に平行に配置された複数の燃料棒、を有す
る核燃料集合体において、前記下部ノズルの冷却
材流通孔を矩形断面として碁盤目状に形成し、各
冷却材流通孔を画成するリブの交点を前記燃料棒
の軸心に整列させてなることを特徴とする核燃料
集合体。 an upper nozzle and a lower nozzle each having a large number of coolant flow holes; a plurality of hollow tubes communicating between the two nozzles and arranged parallel to each other; the hollow tubes being spaced apart in the longitudinal direction; In a nuclear fuel assembly having a fixed support grid and a plurality of fuel rods inserted and supported through each opening of the support grid and arranged in parallel to each other, the coolant flow holes of the lower nozzle are arranged in a rectangular cross section. A nuclear fuel assembly characterized in that the ribs are formed in a mesh shape and the intersection points of ribs defining each coolant flow hole are aligned with the axis of the fuel rod.