Study Of The Adsorption Of Porous Pyridine Basic Resins Towards Technetium And The Radiation Stability

⁹⁹Tc is one of the long half-life fission products with half-life of 2.13×10⁵ years,which generated during the operation of nuclear power plants,with fission yield of 6.13%.Due to high mobility in the environment,so ⁹⁹Tc will result in long-term harm.Porous weakly basic resin 4VP-DVB was synthesized by suspension polymerization,and the strongly basic resin 4VP-DVBQ was synthesized by the quaternization process.Considering rhenium?Re?and Tc are both VIIB elements,with the same chemical properties,so Re was selected to simulate the adsorption behavior of technetium first.In the batch experiment,effect of acidity on adsorption efficiency,adsorption thermodynamics,adsorption kinetics and adsorption isotherm models were studied.And the result shows the 4VP-DVB resin has high adsorption efficiency toward Re?VII?in 0.1 mol/L nitric acid solution,and the adsorption equilibrium can be achieved in 30 min and the adsorption capacity of Re?VII?is about 352.1 mg/g.On the other hand,the adsorption capacity of Re?VII?on 4VP–DVBQ is297.6 mg/g in the same condition.In the column experiment,the4VP-DVB resin has good regeneration behavior and Re?VII?is easy desorbed by 1 mol/L ammonium hydroxide.Then the adsorption of technetium was studied.It was focus on effect of acidity on adsorption efficiency and adsorption kinetics,the similar result with Re proved the feasibility of Re as analogue to⁹⁹Tc.Then the 4VP-DVB resin separate the technetium from the uranium in the column experiment.The radiation decomposition problem of ion exchange resin in the actual use receives much attention.In this paper,4VP-DVB and 4VP-DVBQ were studyied the irradiation stability of air,water,hydrochloric acid and nitric acid under different absorbed doses.For the gas phase product,the relationship between the amount of H₂,CO,CO₂ and CH₄ and the absorbed dose was investigated.The effects of total organic carbon?TOC?and NH₄⁺generation and irradiation factors on the liquid product were investigated.And the adsorption properties of Tc to the resin after irradiation were evaluated.The results show that the stability of 4VP-DVB resin in hydrochloric acid is high,and the irradiation stability of 4VP-DVBQ resin in nitric acid is high.The study of adsorption properties and radiation stability laid the foundation for the application of two types of resins in spent fuel reprocessing.