Improving the temperature resistance of control rod drive mechanism is always one of the development directions of improving the performance of control rod drive mechanism. For the control rod drive mechanism, the temperature resistance of the whole machine mainly depends on the temperature resistance of the electromagnetic coil.
In order to further improve the temperature resistance level of the electromagnetic coil, the professional group of control rod drive mechanism carries out technical research from the aspects of structure, materials, manufacturing process, etc. through the establishment of QC group and youth commando team, the impact of the epidemic situation is overcome to ensure the completion of the project on schedule and with high quality. Finally, a new type of high temperature resistant electromagnetic coil with 440 temperature resistance grade was successfully developed.
One group discussion in November 2019
The temperature resistance of the solenoid coil of AP1000 reactor type control rod drive mechanism is 220. The electromagnetic coil of EPR reactor type control rod drive mechanism in France has a temperature resistance rating of 350.
Compared with the two, the temperature resistance level of the newly developed electromagnetic coil is 100% and 25% higher respectively, reaching the world leading level. Moreover, the control rod drive mechanism with 440 level electromagnetic coil has the ability of long-term operation without ventilation and cooling, which is verified by theoretical calculation and test.
Based on the above development and test verification, "440 level high temperature resistant coil is used as the control rod drive mechanism" as a major improvement item, which has been successfully approved in two high power reactor projects of Zhangzhou 1 / 2 unit and Changjiang 3 / 4 unit, and 440 level high temperature resistant coil has been adopted in two projects. In addition, the ml-c type control rod drive mechanism used in Hainan Changjiang module demonstration small reactor project also applies 440 class high temperature resistant coil. So far, five units of three projects have determined to apply 440 class high temperature resistant coil.
The successful development of 440 grade high temperature resistant coil can cancel the ventilation and cooling system of the control rod drive mechanism on the top of the reactor, simplify the structure of the top of the reactor, save the installation cost, shorten the construction period, and improve the economy of hualong-1. At the same time, it also improves the reliability and service life of the whole control rod drive mechanism, thus improving the safety of Hualong I.
In the huge and complex nuclear reactor system, the electromagnetic coil is like a neuron on the human body, seemingly insignificant, but actually implicated in thousands of things. It is these small neurons that determine the life vein of the whole system; it is these small neurons that are the basis point for us to bring forth the old and bring forth the new; it is also these small neurons that excite the giant dragon that has already taken off to a higher heaven!
Wu Hao, Li Hao, Design Institute