Theoretical Analysis of the Working Performance of the Hydraulic Control Rod Driving System in Perturbation or Inclination

A new type of control rod driving system, the hydraulic control rod driving system (HCRDS) with a hole-hole step cylinder, has been applied in the 5-MW nuclear heating reactor of Tsinghua University for several years and has performed well all along. A second-generation HCRDS has been developed based on operational experience, and further improvements are being carried out.

This paper focuses on the first-generation HCRDS, analyzing in detail its working performance in an unstable state. The control rod stability after minute perturbation and the operation of the control rod in an incline state have been theoretically calculated. The study proves the self-lock design characteristic of the system. The calculated results also indicate that the control rod step-up, step-down, and scram operations function properly.

The theoretical analysis proves the HCRDS reliable and safe, establishing a baseline for further research and development for wide use in portable seawater distillation systems.