Key Parameters Determination of Integral-Plate Cruciform Control Rod

Abstract Integral-Plate cruciform control rod is a new type of control rod designed and manufactured by the Institute of Nuclear and New Energy Technology (INET), Tsinghua University. Cruciform control rod is assembled by two longitudinal slotted absorber plates which are perpendicular and inserted into each other. Hundreds of holes are drilled, symmetrically from each flank of the wing plates to the center. Most holes are designed to contain B4C absorber elements, and the other ones are used to connect the gas space. Compared to the conventional “absorber-rod & cladding-sheet” design, the new type control rod has more B4C loading amount under the same height of absorption zone. The Integral-Plate design can effectively reduce the overall thickness and weight, improve the mechanical performance, and cut down the cost and manufacturing difficulty. Plate thickness, hole diameter, hole spacing and other parameters determine the neutron absorption capacity and structural characteristics of the control rod, which are the key parameters affecting the performance and economy of the Integral-Plate cruciform control rod. In the design process, constraints of the engineering technology should be considered, and the economy should be improved as much as possible on the premise of ensuring the performance. In this paper, a method of determining the parameters such as diameter and spacing of absorber holes under a series of different plate thickness is established by means of performance and mechanical analysis, which provides convenience for the design of Integral-Plate cruciform control rod in different reactor core parameters.