ŠKODA JS Obtained Patent for Method for Manufacturing Control Rod Drive Mechanism Suspension Rods

The Czech Republic Industrial Property Office issued Patent No. 310619 to ŠKODA JS for the method for manufacturing control rod drive mechanism suspension rods for VVER-1000 or VVER-1200 reactor facilities. The invention is aimed at manipulating control rods inside the reactor core. The company reported this on its LinkedIn page.

To enable the operators and instrumentation to determine the exact position of the control rod, a shunt is provided on the drive rod. It is a special technical device consisting of magnetic and non-magnetic sections connected in series. Sensors detect these magnetic marks determining the control rod insertion depth. Traditionally, such component part manufacturing is a complex technological process. The invention provides for modular design of the control rod drive mechanism suspension rods. A hollow rod made of non-magnetic material is taken as a basis. Short cylindrical magnetic segments are manufactured separately. Their diameter is a little bit smaller than internal diameter of the base-tube. These cylinders are inserted to the hollow shunt and fixed in strictly defined places.

Due to new technology, there are no problems during thermal expansion of different materials, since the length difference of separate magnetic segments of the shunt is not significant and beside that, separate cylindrical magnetic segments of the shunt move together with the hollow rod segments in which they are placed.

The proposed invention will allow to eliminate the effect of different thermal expansion of the materials and reduce the risk of loss of measuring signal during operation and costs associated with equipment shutdown, modifications, corrections and additional adjustments.

Technical solution increases the reliability of the position indicator and its accuracy when determining position under normal and high temperature modes.

Based on the data of the Czech Republic Industrial Property Office