EXPERIENCE ON TREATING LIQUID RADIOACTIVE WASTES OF THE RUSSIAN STATECENTER OF NUCLEAR SHIPBUILDING

摘要

Various liquid radioactive wastes (LRW) are produced during the repair and technical maintenance ofatomic submarines at State Engineering Enterprise (SEE) “Zvezdochka”, among them being low mineralizedand low salt content LRW. The Scientific and Industrial Association (SIA) “Radon” began activities intreating those wastes since 1996. The SIA “Radon” specialists developed and constructed a mobile moduletypefacility “ECO-3” for the treatment and utilization of low mineralized low level LRW. The operation offacility is based on sorption-membrane purification technology and concentration of LRW followed byconditioning of concentrate in the standard type 200 liters drums, which are disposed of in repositories. Thefacility consists of two main LRW purification units: Sorption unit; Electrochemical membrane unit. Themajor LRW streams purified by the mobile facility “ECO-3” at the SEE “Zvezdochka” are as follows:1. 400 m3 of low salt content LRW from the Facility 159 in 1997 [1];2. 820 m3 of low salt content LRW from the tanker ?Osetia? in 1999 when the tanker was completelyemptied from LRW [2];3. 350 m3 of low salt content LRW from the Facility 159 in 2000, this works being continued now.Secondary radioactive wastes produced during the purification campaigns were conditioned. Purifiedwaters from radionuclides and chemical contaminants were discharged into purification tanks.A particular feature of given technology consists in application of Electro-osmosis apparatus forconcentration with non-flowing liquor chambers. The purpose of this scheme is to enhance the degree ofconcentration of radionuclides in a small volume and to increase the operation reliability of thedemineralisation Electro-dialyser. Due to this feature it was possible to obtain the final concentrate saltcontent up to 200 g/l, this concentrate being solidified by cementation.The report comprises the flow-sheet diagram of the facility, the results of radiometric and spectrometricmeasurements, the results of chemical analyses of both initial and purified liquids, technical parameters ofapparatuses and technological features of their operation.