In September 1987 an accident occurred with a cesium chloride (CsCl) teletherapy source taken from a cancer therapy institute in Goiânia, Brazil. Misuse of the abandoned source caused widespread contamination of radioactive material (about 50 TBq of Cs) in the town of Goiânia. Decontamination of affected areas did lead to about 3,500 m of solid radioactive wastes, which were disposed in two nea...

Phytoremediation of radioactive waste is a process that uses plants to remove, transfer, or immobilize radionuclides from the contaminated soil, sediment, sludge, or water, and it is a useful method for treating large-scale low-level radionuclide contamination. However, there have not been established criteria which can be utilized to screen out suitable plant species that are capable of remedi...

The objective of this research is to develop a fundamental understanding of the physico-chemical mechanisms that cause foaminess in the DOE High Level (HLW) and Low Activity radioactive waste separation processes and to develop and test advanced antifoam/defoaming agents. Antifoams developed for this research will be tested using simulated defense HLW radioactive wastes obtained from the Hanfor...

A key challenge over the next decade for some national programmes and an important learning opportunity for many others will be the construction and operation of the first deep geological repositories for High Level Waste (HLW) and Spent Fuel (SF). As the orientation of work on disposal shifts from mainly research, development and demonstration to industrial implementation, waste management age...

WENG-SHENG KUO B.S. Mechanical Engineering, Chung-Cheng Institute of Technology, Taiwan, R.O.C (1981) M.S. Nuclear Engineering, National Tsing-Hwa University, Taiwan, R.O.C. (1986) SUBMITTED TO THE DEPARTMENT OF NUCLEAR ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREES OF NUCLEAR ENGINEER and MASTER OF SCIENCE IN NUCLEAR ENGINEERING at the MASSACHUSETTS INSTITUTE OF TECHNOL...

Swiss Legislation requires for all types of radioactive waste the safe and permanent disposal in deep geological repositories within Switzerland by stipulating a step-by-step procedure for site selection and licensing of the disposal facilities. Each step requires safety considerations or safety analyses which are reviewed by the Swiss Federal Nuclear Safety Inspectorate. The principle steps of...

Highly compacted sand-bentonite mixtures are often considered as possible engineered barriers in deep high-level radioactive waste disposals. In-situ, the saturation of these barriers from their initially unsaturated state is a complex hydro-mechanical coupled process in which temperature effects also play a role. The key parameter of this process is the unsaturated hydraulic conductivity of th...

Geological storage is an important concept for high-level radioactive waste (HLW) disposal, and detailed studies are required to protect the environment from contamination by radionuclides. This paper presents a series of geomechanical studies on the site selection for HLW disposal in the Alxa area of China. Surface investigation in the field and RQD analyses on the drill cores are carried out ...

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Models that calculate the probability that a new volcano or a dike from a nearby eruption will intersect the footprint of the proposed high-level nuclear waste repository are generalized based on a conceptual model developed for the space transportation industry. The proposed hazard area, defined such that every new eruption that occurs there will disrupt the repository, plays a fundamental rol...