A study on waterproof capabilities of the bentonite-containing engineered barrier used in near surface disposal for radioactive waste

Study of nuclear fuel cycle in Vietnam at the aspect of domestic production, the exploitation and process of uranium ore were began. These processes generated large amounts of radioactive waste overtiming. The naturally occurring radioactive material and technologically enhanced radioactive material (NORM/TENORM) waste, which would be large, needs to be managed and disposed reasonably by effectivemethods. It was therefore very important to study the model of the radioactive waste repository, where bentonite waterproofing layer would be applied for the low and very low level radioactive waste in disposal site. The aim of this study was to obtain the preliminary parameters for low-level radioactive waste disposal site suitable with the conditions of Vietnam. The investigation of the ratio between soil and bentonite was interested in the safety of the uranium tailings disposal site. The experiments with some layers of waterproofing material with the ratio of soil and bentonite are 75/25; 50/50; 25/75 were carried out to test the moving of uran nuclide through these waterproofing material layers. Waterproofing layers containing bentonite combined with soil were compacted into PVC pipes. One end of the plastic tube is sealed, the other end is embedded in a solution containing uranium nuclide. Analyzing the uranium content in each layers (0,1 cm) of material pipe is to determine the uranium nuclide adsorption from solution into the material in the different ratios at the different times: 1, 2 and 3 month. The results showed that the calculated average speeds of the migration of uranium nuclide into the soil- bentonite layer are 5.4.10-10, 5.4.10-10 and 3,85.10-10 m/s and thickness waterproofing layer (for 300 years) are 4,86 m, 4,86 m and 3,63 m for layer with the ratio of soil and bentonite are 75/25; 50/50; 25/75 respectively

Regulatory approach to management of radioactive waste generated during remediation activities in the Chernobyl contaminated areas

This paper does not necessarily reflect the views of the International Commission on Radiological Protection. It is known that remediation activities in areas affected by radiological accidents may result in generation of huge volumes of very low-level radioactive waste that can overwhelm national capabilities, and be outside of the existing national regulation requirements for radioactive waste management. This may pose a challenge for adoption of an adequate strategy for remediation waste management and application of regulatory requirements that are commensurate with the waste hazard. The Republic of Belarus faced this problem after the Chernobyl accident when performing remediation activities in the contaminated areas. This article presents the experience of the Republic of Belarus in overcoming the challenges and conflicts that arose in the process of developing a rational strategy for safety management of remediation waste, and its justification and optimisation, bearing in mind the need to adopt advanced regulatory instruments of relevance to the management of this waste.

Liquid Low-Level Radioactive Waste Treatment Using an Electrodialysis Process

In this work, the possibility of using electrodialysis for the treatment of liquid low-level radioactive waste was investigated. The first aim of the research was to evaluate the influence of the process parameters on the treatment of model solutions with different compositions. Subsequent experimental tests were conducted using solutions containing selected radionuclides (60Co and 137Cs), which are potential contaminants of effluents from nuclear power plants, as well as components often found in waste generated from industrial and medical radioisotope applications. The results of the experiments performed on real radioactive waste confirmed that electrodialysis was a suitable method for the treatment of such effluents because it ensured high levels of desalination and rates of decontamination. The most important parameters impacting the process were the applied voltage and electrical current. Moreover, this research shows that the application of the ED process enables the separation of non-ionic organic contaminants of LLW, which are unfavorable in further stages of waste predisposal.