| 摘要 |
PURPOSE:To control the reactivity of a reduction means following the temperature change, by controlling the circulating amount of the reduction means in a nuclear reactor which controls its reactivity by controlling the temperature of the reduction means, and also by controlling the position of a controlling rod and the density of a poison. CONSTITUTION:A control rod 2 is controlled in such a manner that a driving mechanism 4 for the control rod is operated in response to a feedback signal of a neutron flux, thereby to insert the control rod 2 or extract the same. If the neutron flux exceeds the proper range of control, a detecting device 9 generates an extraction stopping signal so as to forcibly stop the control rod. Meanwhile, the control by the poison density is carried out by increasing or decreasing the poison density in a heavy water circulating loop 11. The density of the poison is controlled by a density controlling system 7, and thereafter the poison is sent to the loop 11. The heavy water including the poison is, through a distributing pipe 12 and a controlling rod guide pipe 3, introduced to a nuclear reactor 1. After the poison density in the reactor 1 is controlled, the heavy water is circulated in the loop 11 via a circulating pump 15. A signal detected by temperature detectors 13 and 14 which detect respectively the temperature of the heavy water at an entrance and an exit of the reactor is inputted to a reactivity controlling device 23 which in turn outputs a signal to a flow controlling valve 16 of the heavy water, etc., so that the reactivity of the reduction means with respect to the temperature is controlled. |
