Control Drum Drive Mechanism and Regulation Characteristics of the TOPAZ II Reactor

Presented in this paper is a description of the TOPAZ II reactor control mechanism and its mathematical model. During the operating life of the reactor, control is primarily affected by the main control drum because of the inherent characteristics designed into the control drum drive system. The remaining drums become effective only when it is necessary to compensate for large reactivity changes, such as those experienced during start‐up, large power changes, and burnup of fuel.Also presented are results from analyses of typical modes of operation. Representative system responses during the operation of one drum and several drums are included. Results of the analyses performed by Russian and American specialists are compared.