Comparison of costs for alternative mixed low-level waste treatment systems

Total life cycle costs (TLCCs), including disposal costs, of thermal, nonthermal and enhanced nonthermal systems were evaluated to guide future research and development programs for the treatment of mixed low-level waste (MLLW) consisting of RCRA hazardous and low-level radioactive wastes. In these studies, nonthermal systems are defined as those systems that process waste at temperatures less than 350 C. Preconceptual designs and costs were developed for thirty systems with a capacity (2,927 lbs/hr) to treat the DOE MLLW stored inventor y(approximately 236 million pounds) in 20 years in a single, centralized facility. A limited comparison of the studies` results is presented in this paper. Sensitivity of treatment costs with respect to treatment capacity, number of treatment facilities, and system availability were also determined. The major cost element is operations and maintenance (O and M), which is 50 to 60% of the TLCC for both thermal and nonthermal systems. Energy costs constitute a small fraction (< 1%) of the TLCCs. Equipment cost is only 3 to 5% of the treatment cost. Evaluation of subsystem costs demonstrate that receiving and preparation is the highest cost subsystem at about 25 to 30% of the TLCC for both thermal and nonthermal systems. These studies found no cost incentives to use nonthermal or hybrid (combined nonthermal treatment with stabilization by vitrification) systems in place of thermal systems. However, there may be other incentives including fewer air emissions and less local objection to a treatment facility. Building multiple treatment facilities to treat the same total mass of waste as a single facility would increase the total treatment cost significantly, and improved system availability decreases unit treatment costs by 17% to 30%

Markov Properties of Electrical Discharge Current Fluctuations in Plasma

Using the Markovian method, we study the stochastic nature of electrical discharge current fluctuations in the Helium plasma. Sinusoidal trends are extracted from the data set by the Fourier-Detrended Fluctuation analysis and consequently cleaned data is retrieved. We determine the Markov time scale of the detrended data set by using likelihood analysis. We also estimate the Kramers-Moyal's coefficients of the discharge current fluctuations and derive the corresponding Fokker-Planck equation. In addition, the obtained Langevin equation enables us to reconstruct discharge time series with similar statistical properties compared with the observed in the experiment. We also provide an exact decomposition of temporal correlation function by using Kramers-Moyal's coefficients. We show that for the stationary time series, the two point temporal correlation function has an exponential decaying behavior with a characteristic correlation time scale. Our results confirm that, there is no definite relation between correlation and Markov time scales. However both of them behave as monotonic increasing function of discharge current intensity. Finally to complete our analysis, the multifractal behavior of reconstructed time series using its Keramers-Moyal's coefficients and original data set are investigated. Extended self similarity analysis demonstrates that fluctuations in our experimental setup deviates from Kolmogorov (K41) theory for fully developed turbulence regime.Comment: 25 pages, 9 figures and 4 tables. V3: Added comments, references, figures and major correction

Costs of mixed low-level waste stabilization options

Selection of final waste forms to be used for disposal of DOE`s mixed low-level waste (MLLW) depends on the waste form characteristics and total life cycle cost. In this paper the various cost factors associated with production and disposal of the final waste form are discussed and combined to develop life-cycle costs associated with several waste stabilization options. Cost factors used in this paper are based on a series of treatment system studies in which cost and mass balance analyses were performed for several mixed low-level waste treatment systems and various waste stabilization methods including vitrification, grout, phosphate bonded ceramic and polymer. Major cost elements include waste form production, final waste form volume, unit disposal cost, and system availability. Production of grout costs less than the production of a vitrified waste form if each treatment process has equal operating time (availability) each year; however, because of the lower volume of a high temperature slag, certification and handling costs and disposal costs of the final waste form are less. Both the total treatment cost and life cycle costs are higher for a system producing grout than for a system producing high temperature slag, assuming equal system availability. The treatment costs decrease with increasing availability regardless of the waste form produced. If the availability of a system producing grout is sufficiently greater than a system producing slag, then the cost of treatment for the grout system will be less than the cost for the slag system, and the life cycle cost (including disposal) may be less depending on the unit disposal cost. Treatment and disposal costs will determine the return on investment in improved system availability

THE ZIRFLEX PROCESS INTERIM DEVELOPMENT SUMMARY

The Zircaloy-clad fuels and the application of the Zirflex Process for dissolution are discussed. Zirflex chemical flowsheets are presented as developed by pilot plant operatlons. The Zirflex Process is applicable to the reprocessing of fuels from the Dresden Reactor and the PWR Reactor. Other applications of the process are the Plutonium Recycle Test Reactor fuels and the New Production Reactor fuels, possible fuels from the Experimental Breeder Reactor; NPD-2 fuels; and fuels from Carolina-Virginia Nuclear Power Associates Reactor. (W.L.H.

Integrated process analysis of treatment systems for mixed low level waste

Selection of technologies to be developed for treatment of DOE`s mixed low level waste (MLLW) requires knowledge and understanding of the expected costs, schedules, risks, performance, and reliability of the total engineered systems that use these technologies. Thus, an integrated process analysis program was undertaken to identify the characteristics and needs of several thermal and nonthermal systems. For purposes of comparison, all systems were conceptually designed for a single facility processing the same amount of waste at the same rate. Thirty treatment systems were evaluated ranging from standard incineration to innovative thermal systems and innovative nonthermal chemical treatment. Treating 236 million pounds of waste in 20 years through a central treatment was found to be the least costly option with total life cycle cost ranging from $2.1 billion for a metal melting system to$3.9 billion for a nonthermal acid digestion system. Little cost difference exists among nonthermal systems or among thermal systems. Significant cost savings could be achieved by working towards maximum on line treatment time per year; vitrifying the final waste residue; decreasing front end characterization segregation and sizing requirements; using contaminated soil as the vitrifying agent; and delisting the final vitrified waste form from Resource Conservation and Recovery Act (RCRA) Land Disposal Restriction (LDR) requirements

Ceramic and glass radioactive waste forms

This report contains 14 individual presentations and 6 group reports on the subject of glass and polycrystalline ceramic radioactive waste forms. It was the general consensus that the information available on glass as a waste form provided a good basis for planning on the use of glass as an initial waste form, that crystalline ceramic forms could also be good waste forms if much more development work were completed, and that prediction of the chemical and physical stability of the waste form far into the future would be much improved if the basic synergistic effects of low temperature, radiation and long times were better understood. Continuing development of the polycrystalline ceramic forms was recommended. It was concluded that the leach rate of radioactive species from the waste form is an important criterion for evaluating its suitability, particularly for the time period before solidified waste is permanently placed in the geologic isolation of a Federal repository. Separate abstracts were prepared for 12 of the individual papers; the remaining two were previously abstracted