METHOD FOR DECONTAMINATING LOW- MINERALIZED AND LOW-ACTIVE LIQUID WASTES UNDER FIELD CONDITIONS Russian patent published in 2000 - IPC

FIELD: decontaminating liquid radioactive wastes using membrane-sorption method. SUBSTANCE: method involves pre-cleaning of low-mineralized and low-active liquid wastes in mechanical filters and ultrafilters followed by their supply to intermediate tank wherefrom liquid wastes are conveyed to back-osmosis apparatus which returns concentrate (50-90% of liquid waste flow) to same tank; then demineralized solution is finally cleaned by means of H⁺-cation and OH^--anion exchangers reconditioned by H₂, SO₄, and NaOH. Back-osmosis waste condensate is subjected to reagent softening involving its alkalization by waste reagents of anions with hardness salt sediment and corrosion product hydroxides being separated and clarified solutions neutralized before being returned to intermediate tank by waste reagents of cation-exchange resins. Saturated radioactive concentrate and its post-softening sediments formed as result of processing are immobilized by including them in portland blast-furnace slag cement. Amount of beta-nuclides removed in the process increases by four or five orders of magnitude and leachability from solidified products is not over 1•10^-3 g/sq. cm a day. EFFECT: improved degree of liquid waste decontamination. 1 dwg, 1 ex