| 摘要 |
<p>1279654 Moderators BRITISH NUCLEAR DESIGN & CONSTRUCTION Ltd 28 Aug 1970 [29 Aug 1969] 43084/69 Heading G6C A nuclear reactor moderator block has a plurality of identical parallel fuel channels extending through it, and in each of three segmented areas of the of the block which are bounded by three radii of the block disposed at 120 degrees to one another, the channels are disposed, in a regular triangular pattern, in rows parallel to the three radii, those channels which in any one of the segmental areas are nearest to one of the two radii bounding that area being so positioned that they form a square pattern with the nearest channels in the adjacent segmental area on the other side of that radius. The block shown in Fig. 2 is of hexagonal cross-section and the segmental areas are defined by lines extending from alternate corners 4 to the centre of the block. The channels 2 house the reactor fuel elements. This arrangement of the channels 2 provides a relatively large central area which may contain one or more additional channels each adapted to receive a control rod. Alternatively, as in the embodiment shown, a central channel 5 having lifting tool locating features 6 is provided for receiving moderator handling means, a longitudinal groove 7 is provided in a corner 8 of the block, and keying features comprising recesses 9 are provided at alternate corners 4 of the upper end of the block with mating dowels (not shown) provided in corresponding positions at the lower end of the block. The groove 7 of this block, together with corresponding grooves of two adjacent blocks, provides a space for accommodating a control rod column 11. Small cylindrical channels (not shown) which house burnable poison rods may be provided within the block, axially of each recess 9.</p> |
