IMPACT OF IRRADIATION AND THERMAL AGING ON DWPF SIMULATED SLUDGE PROPERTIES

Eibling, R ; Michael Stone, M

Savannah River Site (S.C.)

关键词: Sludges;    Aging;    Testing;    Filtration;    Irradiation;   

DOI  :  10.2172/893950
RP-ID  :  WSRC-TR-2005-00543
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  893950

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. While actual waste samples are the ideal materials to study, acquiring large quantities of actual waste is difficult and expensive. Tests utilizing actual high-level waste require the use of expensive shielded cells facilities to provide sufficient shielding for the researchers. Nonradioactive waste simulants have been used for laboratory testing, pilot-scale testing and full-scale integrated facility testing. 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 on the impact of irradiating a Sludge Batch 3 (SB3) simulant and of additional tests on aging a SB3 simulant by additional thermal processing. Prior simulant development studies examined methods of producing sludge and supernate simulants and processes that could be used to alter the physical properties of the simulant to more accurately mimic the properties of actual waste. Development of a precipitated sludge simulant for the River Protection Project (RPP) demonstrated that the application of heat for a period of time could significantly alter the rheology of the sludge simulant. The RPP precipitated simulant used distillation to concentrate the sludge solids and produced a reduction in sludge yield stress of up to 80% compared to the initial sludge properties. Observations at that time suggested that a substantial fraction of the iron hydroxide had converted to the oxide during the distillation. DWPF sludge simulant studies showed a much smaller reduction in yield stress ({approx}10%), demonstrated the impact of shear on particle size, and showed that smaller particle sizes yielded higher yield stress products. The current study documented in this report focuses on the SB3 sludge composition and recipe developed during the previous year as part of the simulant development program. The study examines the impact of a rapid dose of radiation on the physical properties of the SB3 simulant, the effect of temperature and time on the application of heat as a simulant aging mechanism, and the application of crossflow filtration to the production of an all-metals-precipitated SB3 sludge simulant.