|ognizant Communication Corporation|
A Journal of Science Serving Legislative, Regulatory, and Judicial Systems
Human Advancement · Environmental Protection · Industrial Development
Volume 9, Number 3
Technology, Vol. 9, pp. 111-117
1072-9240/03 $20.00 + 00.
Copyright © 2003 Cognizant Communication Corp.
Printed in the USA. All rights reserved.
Chemical Durability of Soda-Lime-Silicate Glass for Vitrification of Radioactive Waste
Frank H. Eppler* and Man-Sung Yim
North Carolina State University, Raleigh, NC 27695
This study examined the use of soda-lime-silicate glasses for the vitrification of radioactive waste. Tasks performed include: production of glass samples with the incinerator ash from the processing of low-level radioactive waste; testing the chemical durability of the glasses by using the MCC-1 leach test; analyzing the leachate samples with inductive coupled plasma (ICP) mass spectrometric technique; and performing scanning electron microscope (SEM) testing and desk top spectrum analysis on the samples. To understand how the durability of the glass product was influenced by the composition variations within the waste feed, sensitivity study experiments were also performed. All of the leach rate data obtained in this study fell within a factor of 3 of the reported forward dissolution rate of the borosilicate glass. Although the long-term performance issue was not investigated, the results may indicate a role for the soda-lime-silicate glasses in the immobilization of low-level or mixed waste. Increases in CaO or Na2O caused the most significant increase in the leach rates in the sensitivity studies. Durability of the proposed waste glass could be improved with proper use of oxides such as Al2O3, Fe2O3, or P2O5-3.
Key words: Soda-line-silicate glass; Radioactive waste; Vitrification; Chemical durability
Address correspondence to Man-Sung Yim, North Carolina State University, Raleigh, NC 27695. Tel: (919) 515-1466; Fax: (919) 515-5115; E-mail: email@example.com
*Presently with Duke Engineering and Services, Charlotte, NC.
Voluntary Cleanup of the Ames Chemical Disposal Site
Anibal L. Taboas,1 Richard Freeman,1 and John Peterson2
1U.S. Department of Energy, 9800 S.
Cass Avenue, Argonne, IL 60439
2Argonne National Laboratory, Argonne, IL 60439
The U.S. Department of Energy completed a voluntary removal action at the Ames chemical disposal site, a site associated with the early days of the Manhattan Project. It contained chemical and low-level radioactive wastes from development of the technology to extract uranium from uranium oxide. The process included the preparation of a Remedial Investigation, Feasibility Study, Baseline Risk Assessment, and, ultimately, issuance of a Record of Decision. Various stakeholder groups were involved, including members of the regulatory community, the general public, and the landowner, Iowa State University. The site was restored and returned to the landowner for unrestricted use.
Key words: Ames chemical disposal site; Site cleanup; Chemical waste; Low-level radioactive waste
Address correspondence to Richard Freeman, U.S. Department of Energy, 9800 S. Cass Avenue, Argonne, IL 60439. Tel: 630-252-2645; Fax: 630-252-2654; E-mail: Richard.Freeman@CH.DOE.GOV
Assessment of Trace Metals on Phytoplankton Species Diversity in Kuwait Coastal Areas Using a Biomonitoring Study
A. H. Bu-Olayan,1 B. V. Thomas,1 and R. Al-Hassan2
1Department of Chemistry and 2Department of Biological Sciences, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait
Species diversity (H´), evenness index (J), and the index for dominance (l´) were in the range 0.76-1.33 bits/unit, 0.38-0.66, and 0.06-0.59, respectively, for the phytoplankton community sampled in seven stations along the Kuwait coast. Evenness index (J) was found to increase with increasing H´ in phytoplankton. Seasonally, in phytoplankton, an inverse correlation was observed between species richness indices (R1 and R2). Similar observation was also noted between H´ and l´. Despite an increase in trace metal levels in seawater, moderately rich species diversity was observed in Station III that could be attributed to the rich nutrient and constant upwelling of water current. However, a comparative study revealed low diversity indices correspondingly to the increase in trace metal levels in phytoplankton collected from Stations I-II and IV-VII. Hence, these indices will support baseline studies in assessing the synergistic relationship between phytoplankton diversity and major trace metal levels that cause marine pollution in Kuwait coastal waters.
Key words: Trace metals; Phytoplankton diversity; Kuwait
Address correspondence to A. H. Bu-Olayan, Department of Chemistry, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait. E-mail: firstname.lastname@example.org