Construction of a large sodium loop and its commissioning

The SSEN-100 sodium loop consists of two main parts, viz., a steady-state part for long-term operation with constant parameters and a nonsteady-state part for modelling transients with coolant temperature changing in time. The specifications and a block diagram of the loop are presented. Following assembly and testing of the individual loop equipment, the loop was filled with sodium by Degussa (FRG). It was purified in a cold trap. The oxygen level in the sodium was measured using a freezing valve. Both parts of the loop were then commissioned. (E.S.)