GB921699A - Restraining means - Google Patents

Abstract

921,699. Moderator structures. BABCOCK & WILCOX Ltd. Jan. 17, 1962 [Jan. 19, 1961], No. 1641/62. Class 39 (4). A restraint garter for applying restraining forces to the sides of a stack of moderator blocks of a nuclear reactor core 1 comprises a heavy, inextensible ring 14 supported by means of displaceable members from a series of heads 7 secured to upright beams 6 placed against the sides of the stack, displacement of these members accompanied by vertical movement of the ring 14 accommodating expansion and contraction of the stack. The flexibility of the beams 6 is increased by grooves 8 opposite the upper and lower edges of each head 7. The displaceable members may be slide plates interposed between wedging surfaces of the heads 7 and the ring 14, rollers provided with pinions engaging surfaces of the heads 7 and the ring 14, rollers provided with pinions engaging complementary tracks on the heads 7 and the ring 14, resilient members rigidly anchored at their ends to the heads 7 and the ring 14, or toggle arms inclined radially outwardly and upwardly from the heads 7 and engaging at opposite ends in complementary recesses in the heads 7 and the ring 14. Alternatively (Fig. 7), the displaceable members may comprise support links 50 hinged at their upper ends to the heads 7 and sloping downwardly and inwardly towards the stack to be pivotally connected at their lower ends to the ring 14 which is carried by the links 50. Guide members 16 fixed to a rigid structure surrounding the core 1 are located in slots 19 in skirts 17 attached to the rings 14 of a number of garters encircling the core 1 at vertically spaced intervals, the skirts being flared to overlap those of the garters immediately above. The inner ends of the guide members 16 are received as a sliding fit in vertical slots 9 in the rings 14. The uppermost skirt is of uniform diameter and has slots 18 in its upper end co-operating with the uppermost guide members 16.