Verfahren zur Beeinflussung der Leistung eines Atomkernreaktors sowie Atomkernreaktor zur Ausübung des Verfahrens

摘要

1,075,361. Controlling reactors. SULZER BROS. Ltd. Aug. 27, 1965 [Sept. 10, 1964], No. 36941/65. Heading G6C. In a nuclear reactor having a number of control rods movable lengthwise into and out of the reactor core, the adjusting movement of the control rods is such that at any given time during operation some of the rods are in one end position, e.g. fully inserted into the reactor core, while some other of the rods are in the other end position, e.g. fully withdrawn, and at least one rod and at most two rods are in an intermediate position between these two end positions. The range of adjustment of the rods is subdivided into three component ranges-a central range and two end ranges- and for as long as only one rod is in an intermediate position such rod is in the central range and immediately, in the event of an adjusting movement, the rod passes over the boundary between the central range and an end range and enters the end range, a rod in the end position of the other end range is moved and, for as long as the first rod makes adjusting movements in the particular end range concerned, follows the movements of the first rod in the same direction. Consequently, there is either one rod in the central range or there are two rods in the opposite end ranges, which feature helps to compensate for the reduced sensitivity of the control in the end ranges. No division of the rods into groups for coarse and fine control is necessary since the two functions are provided by the sequentially connected control rods. Since the nuclear fuel near control rods which are completely inserted in the core all the time is used up relatively less than fuel near rods which are fully withdrawn, the position of the rods is changed periodically. After a few months or after a reactor shut down, the rod sequence can be altered so that rods which were fully inserted now stay fully withdrawn for a time and vice versa. The operating sequence and the physical arrangement of the control rods are such that each freshly inserted control rod is inserted near to the centre of the largest zone which is still devoid of rods.