| 摘要 |
<p>1,031,873. Dissolving nuclear fuel. COMMISSARIAT A L'ENERGIE ATOMIQUE. July 10, 1964 [July 22, 1963], No. 28630/64. Heading G6R. A subcritical nuclear fuel dissolving apparatus comprises a subcritical dissolving vessel 1 in which the fuel to be dissolved is placed and which is located above a subcritical tank 2 containing a treatment solution comprising an aqueous solution of an acid, e.g. HNO3, the volume of this solution contained in the tank 2 being variable according to the quantity of fuel to be dissolved, a boiler 3 which supplies a mixture of solvent and of steam arising from the water of the treatment solution and which assures the circulation of the mixture, the boiler 3 being situated at a position laterally spaced from and below the tank 2, a liquid/vapour phase separator 4 located above the vessel 1, and pipes such as 9, 10 for connecting the different elements of the apparatus. The vessel 1 terminates in a frusto-conical base and is fitted with a detachable cover for the introduction of the nuclear fuel, its dimensions being adapted to those of the fuel to be dissolved. The tank 2 is preferably flat and of trapezoidal shape. The steam from the boiler 3, as well as nitrous vapours when the solvent is HNO3, forms together with the solution a mixture having a lower sp.gr. than that of the solvent which entrains the latter in the liquid phase. The vessel 1 and the tank 2 are fitted with two tubes 9, 10 which serve to eliminate nitrous vapours, which vapours are oxidized by air injected into the tubes and the resulting oxides condensed in condenser 6 if the temperature is sufficiently low. The oxides which are not condensed in the condenser 6 are sent through a tube 11 into a NaOH absorption column. The steam is separated from the solution within the separator 4, sent to the condenser 6 and then returned to the boiler 3. In order to commence the dissolving process in a rapid and uniform manner, air is injected into the apparatus immediately beyond the outlet of the boiler 3 at 7, this injection being stopped as soon as the circulation has achieved a steady state. The treatment solution is drawn off through a conduit 8 at the foot of the apparatus.</p> |
