Research On The Reduction Treatment Method Of Nuclear Power Radioactive Waste Oil

With the development of nuclear power plants in China for several decades,a certain amount of radioactive waste oil has been produced.Because of the small annual output,radioactive waste oil has not been paid enough attentions and no researches have been carried out.Usually,the radioactive waste oil is temporarily stored in the warehouse in nuclear power plants and further treatment hasn't been implemented.As the radioactive waste oil belongs to the organic wastes,it has the fire and explosion risk in the process of temporary storage because of its inflammable and explosive characteristics.Simultaneously,the chemical corrosivity and toxicity also make it difficult in storing.By the research and practice of radioactive waste oil dispose at home and abroad,and combining with the national conditions,the research idea of separating radionuclides from radioactive waste oil has been determined.Oil-water extraction,oxidation aging and ion exchanging were used in researching and some parameters of oil-water extraction were determined.A 100L-scale demonstrated device for disposing radioactive waste oil was developed,and the demonstrated experiment on site was carried out.According to the research,a new technology suitable for the disposing of radioactive waste oil and the suggestions on the technology and devices were put forward.The experimental researches have been carried out with the waste oil produced by nuclear power plants.The feasibility of the technology was preliminarily determined,and the related influencing factors of the disposing methods were studied.It is concluded that the decontamination coefficient of oil-water extraction is about 10,the ratio of oil to water and the temperature of extraction have great influence on the effect of oil extraction,the best proportion of oil to water is near 2:1,the recommended extraction temperature is 75?,the best aqueous phase is p H=2,the recommended stirring time is 1 day,and the separation of oil and water costs about 5~7 days.The decontamination coefficient of oxidation aging is more than 100,the reaction temperature has a great effect on decontamination,more than 160? is necessary for the decontamination.The decontamination coefficient of ion exchanging is 10 and more,and the dosage of resins is the key of the decontamination effect.The combination technology of "oil-water extraction + oxidation aging + ion exchanging" was made.And a 100L-scale demonstrated device for disposing radioactive waste oil was developed.With the device,the demonstrated experiment on site was carried out,in the experiment: after extracting,the radioactive activity of the oil is reduced from 5.10Bq/g to 0.65Bq/g,and is below 0.08Bq/g after the oxidation aging.Combined with the common reusing methods of waste oil in China,the radiation impact assessment of treated oil during the reusing process is made.Respectively,the dose estimation is done by the hypothetical scenario and the modular scenario,the final results are smaller than the 10?Sv/a(normal)and 1m Sv/a(accident).The results meet the requirements of activity concentration for material not requiring radiological regulation(GB27742-2011).It is concluded that the technology of "oil-water extraction +oxidation aging + ion exchanging" and the attaching device are feasible.