IMPACT OF SIMULANT PRODUCTION METHODS ON SRAT PRODUCT

EIBLING, R

Savannah River Site (S.C.)

关键词: Production;    Sludges;    Chemical Reactions;    Testing;    Physical Properties;   

DOI  :  10.2172/890192
RP-ID  :  WSRC-TR-2005-00294
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  890192

美国|英语

来源: UNT Digital Library

【 摘 要 】

The research and development programs in support of the Defense Waste Processing Facility (DWPF) and other high level waste vitrification processes require the use of both nonradioactive waste simulants and actual waste samples. The nonradioactive waste simulants have been used for laboratory testing, pilot-scale testing and full-scale integrated facility testing. Recent efforts have focused on matching the physical properties of actual sludge. These waste simulants were designed to reproduce the chemical and, if possible, the physical properties of the actual high level waste. This technical report documents a study of simulant production methods for high level waste simulated sludge and their impact on the physical properties of the resultant SRAT product. The sludge simulants used in support of DWPF have been based on average waste compositions and on expected or actual batch compositions. These sludge simulants were created to primarily match the chemical properties of the actual waste. These sludges were produced by generating manganese dioxide, MnO{sub 2}, from permanganate ion (MnO{sub 4}{sup -}) and manganous nitrate, precipitating ferric nitrate and nickel nitrate with sodium hydroxide, washing with inhibited water and then addition of other waste species. While these simulated sludges provided a good match for chemical reaction studies, they did not adequately match the physical properties (primarily rheology) measured on the actual waste. A study was completed in FY04 to determine the impact of simulant production methods on the physical properties of Sludge Batch 3 simulant. This study produced eight batches of sludge simulant, all prepared to the same chemical target, by varying the sludge production methods. The sludge batch, which most closely duplicated the actual SB3 sludge physical properties, was Test 8. Test 8 sludge was prepared by coprecipitating all of the major metals (including Al). After the sludge was washed to meet the target, the sludge simulant was heat treated at 98 C for eight hours. Before testing began, it was hypothesized that the SRAT process would eliminate the rheology disparities on the differently prepared test sludges due to the chemistry of the SRAT process. If this hypothesis was true, all of the products would have similar rheological properties. The objective of the project documented in this report was to determine the best method for producing a DWPF simulated sludge based on the physical properties of the SRAT product. In order to determine the best processing method, four SRAT cycles were completed using the four best sludge simulants. The objectives of the testing were: (1) Produce four batches of SRAT product to be used primarily in a rheology study. (2) Develop an improved understanding of the impact of various methods of simulated sludge production on the physical properties of the SRAT product.