DEVELOPMENT OF A TECHNOLOGY FOR WWER-1200 STILL BOTTOM TREATMENT FROM RADIONUCLIDES

The paper presents a method developed to treat still bottoms from WWER-1200 reactor units of the Novovoronezh NPP-2 and Leningrad NPP-2 providing the removal of the main dose-contributing radionuclides (⁷Be, ^59,63Ni, ^124,125Sb,^137,134Cs, ⁶⁰Co, ⁵⁴Mn, ¹¹⁰mAg) via sorption, precipitation, destructive and membrane treatment. The paper proposes a treatment flowchart involving ozonation, filtration, pH adjustment and treatment with the Termoksid-35 sorbent. The study indicates that the specific a- and β-activity of the resulting filtrate after its evaporation to dry salts accounted for < 110 and 1000—3000 Bq/kg respectively, with the latter one explained by the presence of the natural ⁴⁰K iso tope. Material balance assessment of this method showed that the volume reduction factors for the treated RW from Novovoronezh NPP-2 and Leningrad NPP-2 accounted for 132.6 and 36.4, respectively. When these two indicators were recalculated to the LRS volume with an average salt content of ~ 4 g/L, the calculated RW volume reduction factors amounted to ~ 3,900 and ~ 3,270, respectively.

Keywords: liquid radioactive waste, NPP still bottoms, ozonation, filtration, pH adjustment, sorption, Termoksid-35, radioactive waste.

Savkin A. E., Slastennikov Yu. T., Ostashkina E. E., Petrov S. S., Khodalev L. V., Matveenko A. V., Ka shchenko A. A. Development of a Technology for WWER-1200 Still Bottom Treatment from Radionuclides. Radioactive Waste, 2025, no. 4 (33), pp. 18—28. DOI: 10.25283/2587-9707-2025-4-18-28. (In Russian).