Studiecentrum Voor Kernenergie, S.c.k.

Studiecentrum Voor Kernenergie

Aime E Bruggeman

Johan Braet

Philippe Vermeiren

Roger F Leysen

Marcel Monsecour

Rene D Cornelissen

Andre Rahier

A method for separating boric acid from a liquid, especially liquid waste obtained from a nuclear power plant. In the method, the waste solution containing the boric acid is contacted with steam in a reactor so that the boric acid evaporates from the liquid and passes into the steam vapor phase. Consequently, the radioactive wastes which are not evaporated with the steam remain in the waste water while the boric acid is removed from the waste water when it passes into the vapor or steam phase. The boric acid can then be separated and recovered from the steam by means of a distillation and fractionating column or a wash column. By removing the boric acid from the liquid waste, it is possible to obtain concentrated radioactive waste having a reduced volume due to the absence of boric acid in the waste.

Method for separating boric acid

The present invention provides a method for separating boric acid from a liquid, especially liquid waste obtained from a nuclear power plant. In the process, the waste solution containing the boric acid is contacted with steam in a reactor so that the boric acid evaporates from the liquid and passes into the steam vapor phase. Consequently, the radioactive wastes which are not evaporated with the steam remain in the waste water while the boric acid is removed from the waste water when it passes into the vapor or steam phase. The boric acid can then be separated and recovered from the steam by means of a distillation and fractionating column or a wash column. By removing the boric acid from the liquid waste, it is possible to obtain concentrated radioactive waste having a reduced volume due to the absence of boric acid in the waste.

An inorganic gas separator which has a porosity between 30 and 70% and a pore diameter between 10 and 100 .mu.m, and which is gas impermeable when soaked-through with liquid, is mounted in a frame, divides a cell housing into two compartments, and is moistened by capillarity with liquid fed through channels extending in the frame. In each compartment are mounted a porous foil, an electrode, a pre-electrode, a metal plate and an insulating plate. On the cell-housing thermo-electric heat pumps are mounted for cooling and the unit formed by the housing and the pumps is surrounded by an outer casing.

Electrolyser for highly-active tritiated water

Carrier particles whereon a metal from the group VIII of the periodic element system is fixed are dry-mixed with particles from hydrophobic material which is simultaneously a binder and may thus bind the carrier particles together. The thus obtained mixture is subjected to an agglomeration step. The resulting agglomerates are broken. The broken agglomerates are screened and that fraction with a grain size smaller than 1 mm is pressed into a cake at a pressure of 25 kg/cm.sup.2 at the most. The press cake is rolled and catalyst particles are cut from the rolled cake. The catalyst particles are mixed with hydrophilic particles. The thus obtained mixture is used in an isotopic exchange column for separating tritium from aqueous effluents. In this column the effluents are lead in counter-current to gaseous hydrogen.

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Retie, Belgium

Aime E Bruggeman