High-level Waste Management Research Articles

Risk Analysis of Radioactive Waste Management Systems in Germany

Within the scope of a system study,“Radioactive Wastes in the Federal Republic of Germany,” performed from 1974 through 1976, the questions of risk assessment were investigated. A risk analysis of a high-level waste (HLW) management system was performed. The results of the HLW tank storage are that the risk expectation value is 700 nJ/kg × RBE (7 × 10−5 rem) per year for atmospheric release. The discussion of the main contributing accidents shows the possibility of reducing the risk by technical means. A qualitative comparison on a release basis with the results of the WASH-1400 report shows significant differences that can be explained by the different methodologies applied.The risk analysis activities have led to a comprehensive risk assessment project, which was recently started. The project includes research and development tasks concerning nuclide migration and transport to the ecosphere, nuclide mobilization by various mechanisms, methodology problems, data collection, computer code development, as well as risk analyses of waste management facilities. It is intended to round off the project with risk analyses of spent fuel element transport, storage, and reprocessing.

A usable method for the management of high-level waste from nuclear fuel reprocessing

A process for the solidification of high level waste (HLW)-solutions is described. Final product of this process is not, as usual, a glass-block but a block of glass-metal compound called VITROMET. The main features of the process, the properties of the product and the possibilities for engineered storage and disposal are: denitrition of the waste stream, concentration, formation of phosphates or borosilicates, continuous melting, formation of glass beads, incorporation in a corrosion resistant lead-alloy matrix and sealing in a canister that may be placed first in engineered storages then in stable geological formation.

Build-Up and Decay of Actinide Nuclides in Fuel Cycle of Nuclear Reactors

In order to assess the feasibility of utilizing plutonium in thermal reactors, build-up and decay of actinide nuclides have been studied for BWR, PWR, HWR, HTGR and LMFBR, which are uranium-oxide fueled or mixed-oxide fueled, and which produce electric power of 1,000MW. The following items were examined; 1. quantities of actinide nuclides build-up in the reactor 2. build-up and decay of activities of actinides in the spent fuel 3. build-up and decay of activities of actinides after reprocessing, and 4. variation of isotopie composition of plutonium with high burn-up. It is concluded from the calculated results that precautions should be taken against high activities of resultant actinides if plutonium is utilized as a fissile material for thermal reactors. To make reprocessing and high-level waste management easy and practical, it is recommended that a thermal reactor should be fueled with uranium, the plutonium produced in a thermal reactor should be used in a fast reactor, and plutonium produced in the ...

Waste Management — Licensing and Criteria

Waste management is a topic of great importance to industry and the general public, and one that receives a great deal of attention within the regulatory organization. The regulated fuel cycle includes uranium milling, UF6 conversion, fuel fabrication, chemical reprocessing of spent reactor fuel, transportation of nuclear materials, and waste disposal. Management of radioactive waste generated in the nuclear fuel cycle is of particular interest now. A number of policy decisions must be made in the near future and then implemented as regulatory requirements. These decisions must receive public acceptance for safety and protection of environmental values. The main issues pertain to management of high-level waste, management of plutonium bearing waste (including the fuel cladding hulls from reprocessed fuel), stabilization and long-term control of mill tailings, and the application of the “as low as practicable” concept of fuel cycle effluents in light of the current status of technology. Two important studies are presently being carried out by the U.S. Atomic Energy Commission. The first involves the assessment of the environmental effects of utilizing plutonium fuel in light-water reactors; the second is an environmental analysis of the nuclear fuel cycle associated with high-temperature gas-cooled reactor operations. Waste management is significantly represented and evaluated in each of these studies.

The Hidden Commitment of Nuclear Wastes

One of the critical factors that must be considered in the decision-making process required in solving the radioactive waste management problem is the issue of costs. The accumulation of both government- and commercially generated wastes is estimated at some 200 million gal of high-level waste, 400 million ft3 of low-level waste, and 85 million ft3 of alpha wastes by the year 2000. Cost projections are made for high-level waste management (exclusive of ultimate disposal), for low-level waste burial, and for alpha waste burial. These cost estimates indicate some $7 billion to be committed for waste management by the year 2000. In addition, the cost for ultimate disposal of high-level wastes could exceed $1 billion by the year 2000, depending on the government surcharge for handling these wastes. Therefore, explicit attention should be given to the possibility that an interim engineered storage system may become permanent solely due to economic costs.