SU601763A1 - Method of regeneration of cold trap - Google Patents

Description

It relates to the methods of restoring cold lavas and can be used in atomic radiation systems on reactor installations With a liquid-metal coolant. There is a known method of regeneration of cold traps, in which the traps are cleaned from oxides and products of the interaction of water with ', which is produced by distillation and gas method. In this method, waterO2 genus is removed from the bottom of the pot, then the temperature is raised to C, and the bulk of the sodium is distilled off by vacuum distillation, and the residue is dissolved with steam or ethyl opirto1M "water 1. The disadvantage of the method is the need for complete cutting a cold trap from the coil to warm it up to the required temperature and explosion and the danger of food progression due to the possible ignition of sodium and hydrogen or hydrogen. The known method of regenerating cold traps without additional dismantling them from the vacuum circuit,. consisting of extruding the main part of sodium from the volume of the trap with an inert gas followed by removal of the remaining hydrides as a result of their thermal decomposition, for example, at 280-300 ° C. 2 However, in this method, after decomposition of the volatile IB impurities, the trap remains pure metal and unbroken I impurities, i.e., there is not sufficient cleaning of the cold trap. In order to completely remove impurities according to the proposed method, the trap is cooled to 15-20 ° C before removal of impurities, and the subsequent process is carried out by forcibly circulating an aqueous silky solution of 48-50% concentration with periodic introduction of water into the circulating solution. solution at С, This method provides simultaneous and complete removal of hydrides and oxides of the liquid metal carrier and the remaining sodium metal from the cold trap. In addition, the proposed method, carried out at lower temeratures ps compared with the known method, provides for regeneration without possible explosions and ignition of the released hydrogen. For the experimental implementation of the proposed method in the cleaning system of the coolant, a cold trap unit BOR-60 with liquid metal coolant having the following technological characteristics is used: liquid volume

lo-voush (ki zhidko m) metal (U} 1 m, nominal (Passport consumption of the coolant 2-6 and the amount of ullavvvvivaymyh impurities 260 kg.

Example. In the case of the cleaning of the heat-exchange mixer with an internal trap, it is disconnected from the basic alkaline circuit to prevent circulation of the cooling medium through the trap (cold trap filled with a liquid KIM metal and PIMME is dispersed to 200 ° C, after which Inert gas is fed through a slurry line and this way is produced by ejecting liquid metal from the trap to inert gases until it contains the remaining sodium and impurities in an amount of 200 kg. Then the trap is cooled to 20 ° C for 5 h. Alkaline is connected to the cooled trap. .con It is carried out through it by the crushing liquid of the water of the sodium alkaline solution with a 48% concentration and with a filling rate of the trap no more than 1 and with periodic introduction into the circulating paiCPBop for support, and its temperature and temperature of 45 ° C. The indicated introduction of water is plentiful at its hourly consumption of 50 kg / h for dissolution and the size of an individual portion is no more than 200 g. At the same time, the proportion of water consumed in the circulating water solution is released after 1 h. alkaline solution through trapping. Dissolution of the deposit is under a process trap under the above process conditions for 25 hours.

At the end of the process of dissolving the irimeses, the water is washed with a cold lo-wedge. For this, the solution is removed from the alkaline keniur and | Partially removed it from the trap and | by inerting the solution with this solution through the lower edge of the inert gas injection pipe into the trap. Then, the alkaline circuit is filled with water, ra.z .: bavl the alkaline solution thus heated in the trap, and again the alkaline circuit is fed from the circulator.

solution. This washing operation is repeated 2-3 times, reducing the alkali content in the solution to 0.1 weight. % Filling the alkaline circuit circulating m solution

and the circuit is again released from the solution for 1.5 hours. At the end of the washing of the alkaline circuit, the trap is heated and dried for 10 hours. In the cold water regenerated by the proposed method, the metal or acidic sodium hydrides of the metal carrier are completely absent and other impurity oxides.

The predlozhenny method is quite simple and safe in operation, as it allows the complete regeneration of cold cold from impurities without its demo. Installation and the possible ignition of hydrogen in

the system.

Formula inventions

The method of regeneration of a cold trap, including the release of its volume from the melting metal of the inert metal with inert gas meters followed by 1M | Yes, is the freezing liquid from the sump of the trap, characterized by the fact that in order to completely remove impurities, The trap must be cooled to 15-20 ° C before removal of the impurities, and the subsequent application is carried out by forcibly circulating an aqueous alkaline solution with a 48-50% concentration of irn periodical: M injected into the circulating water solution to keep the alkaline solution at a temperature at 45-50 ° C.

Sources of information taken into account in the examination of the invention:

1. Technical problems of fast neutron reactors. Ed. Yu. E. Bagdasarova, Part 1, Ch. P1, § 4, p. 143.

2. Authors Certificate L 429468, cl. G 21 C 15/00, 10/20/22.