A laboratory crucible study was conducted to develop waste forms to treat nonradioactive simulated u8Pu heterogeneous debris waste fiom Savannah River, metal waste fiom the Idaho National Engineering Laboratory (INEL), and nominal waste also fiom INEL using DC arc melting. The preliminary results showed that the different waste form compositions had vastly different responses for each processing effect. The reducing condition of DC arc melting had no significant effects on the durability of some waste forms while it decreased the waste form durability fiom 300 to 700% for other waste forms, which resulted in the failure of some TCLP tests. The right formulations of waste can benefit from devitrification and showed an increase in durability by 40%. Some formulations showed no devitrification effects while others decreased durability by 200%. Increased waste loading also affected waste form behavior, decreasing durability for one waste, increasing durability by 240% for another, and showing no effect for the third waste. All of these responses to the processing and composition variations were dictated by the fbndamental glass chemistry and can be adjusted to achieve maximal waste loading, acceptable durability, and desired processing characteristics if each waste formulation is designed for the result according to the glass chemistry.

This report summarized activities of the TENORM task group of the FNCA held in Thailand during August 23-27, 2004. TENORM inventory, regulations and laws, and the country specific problems are also included in this report. Groups of industries lead to enhanced occupational and public exposure to TENORM in Thailand included oil and gas exploration and production, metal production i. e. tantalum, niobium, tin, and rare earths, cement production, steel refinery, water treatment, coal and coal power production, chemical fertilizer, and residues from past activities with various range of capacity. Waste volume generated and TENORM activity concentrations in waste were estimated based on information from various reports and data. TENORM waste volume generated was estimated 150, 000 ty-with activity concentration ranges from 0. 14-1. 3 Bqg-1 of 226Ra. Thailand has no regulation directly control of NORM and TENORM. However, article 2 of the Thai Ministerial Regulation No. 5 BE. 2516 (1973) clarified: any materials that contained uranium oxide (U308) or thorium oxide (Th02)/ or uranium oxide and thorium oxide at concentrated level more than 15% of the original ore element will be accounted as radioactive source materials. Practical guidance based on BSS No. 115 must be applied on all activities dealing with those materials. The specific problems of the country for controlling TENORM are the lack of: understanding on TENORM sources, information on location and extent of existing TENORM sites, safely and economically guidance on controlling exposure to TENORM, information distribution and cooperation network, and a suitable and correct method on sampling and measurement of TENORM.

A laboratory study performed on three waste streams with high metal content (between 20 and 60 wt%) showed that waste form durability was strongly influenced by processing conditions and waste form compositions. The study involved varying the waste loading, melting conditions, and heat treatment of a total of 15 waste forms. The normalized sodium release obtained from the product consistency test (PCT) was the main criterion used for durability comparisons between each waste form. It was found that a reducing melt condition had no effect on the durability of some waste forms, yet it decreased the durability of others up to 700% when compared to the oxidized melts. One waste form composition tested showed a 140% increase in durability when devitrified (crystallized) relative to its glassy form. Some compositions showed no change in durability after devitrification, while others showed a 200% decrease. Increased waste loading was also found to have varying effects dependent on the composition of the waste form and the processing atmosphere. These responses to processing and composition variations were dictated by fundamental glass chemistry and can be adjusted to achieve maximum waste loading, acceptable durability, and desirable processing characteristics with optimized formulations.

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