Development of a control rod drive for a fast sodium-cooled reactor

Starting from the precise, safety-related, operating technique and geometric data, the individual steps of the concept determination are described and reasons for them are given. Important parts of the concept developed are: an electro-magnetic latched stepped lift as drive in control operation, a pneumatic unit for acceleration to support the dropping movement in a fast shut-down and a hydropneumatic damping at the end of the travel. For experimental investigation, a test rig was erected and a test drive was manufactured, which has the above-mentioned concept characteristics. As the test rig measurements were made in air and in water, a calculation model had to be developed, in order to predict the movement in reactor operational conditions and to be able to vary the design parameters. (orig.)