Tests on Wall Temperatures of the Moderator Cell of the D2 Cold Source in Equilibrium and Transient Regimes.

摘要

A second cold source is planned in the high flux reactor inside an available horizontal channel. A volume exceeding 5 liters of liquid D(sub 2) at a temperature of 25 K is required for good moderation. The moderator is near the core in the glove finger 23 cm in diameter and 5 m long. Thermal insulation of the cold structures from the environment is assured by a vacuum (Fig. 1). A facility near the core means a high heat liberation (3000 W) in the moderating cell, two-thirds of which is liberated in the material (aluminum) and one-third in the moderator itself. The moderator must handle the heat transfer. This can only be achieved with cooling by boiling the moderator in the cell which is in a state of saturation (25 K; 1.5 bars). It evaporates under the effect of the power liberated. The vapor is eliminated from the source in a monophase form, or in a diphase form as a mixture of fluid and vapor and then liquefied outside the glove finger in a condenser in a high position, cooled with helium. The condensed fluid then returns into the cell. This D(sub 2) circuit is supposed to operate without pumps according to the principle of a thermisiphon. That is, the density differences in the input and outlet tubes give rise to circulation of the fluid. 6 refs., 24 figs.