SEPARATION AND EXTRACTION OF PLUTONIUM IN MIXED WASTE

Arthur E. Desrosiers, ScD, CHP ; Robert Kaiser, ScD ; Antkowiak, Jason ; Desrosiers, Justin ; Jondro, Josh ; Kulczyk, Adam

Bartlett Services, Inc. (United States)

关键词: Radiation Doses;    Decontamination;    Wipp;    Quality Control;    Wastes;   

DOI  :  10.2172/821144
RP-ID  :  NONE
RP-ID  :  AC26-01NT41308
RP-ID  :  821144

美国|英语

来源: UNT Digital Library

【 摘 要 】

The Sonatol process uses ultrasonic agitation in fluorinated surfactant solutions to remove radioactive particles from surfaces. Filtering the suspended particles allows the solutions to be reused indefinitely. The current work applies the Sonatol process to the decontamination of heterogeneous legacy Pu-238 waste that exhibits excessive hydrogen gas generation, which prevents transportation of the waste to the Waste Isolation Pilot Plant. Bartlett Services, Inc. (BSI) designed and fabricated a prototype decontamination system within a replica of a Savannah River Site glovebox. In Phase I, BSI conducted cold testing with surrogate waste material to verify that the equipment, operating procedures, and test protocols would support testing with Pu-238 in Phase II. The surrogate waste material is representative of known constituents of legacy job control waste. Two sub-micron sized Pu-238 simulants were added to the surrogate waste so that decontamination could be tested. The first simulant was an Osram Sylvania Phosphor 2284C powder that fluoresces under ultraviolet light. The use of the fluorescent simulant allows rapid, inexpensive system startup testing because residuals can be assayed using a digital camera. The results of digital pixel analysis (DPA) are available immediately and do not require use of licensed material. The second simulant, which was used for integrated cold testing, was a cerium oxide powder that was activated in a research reactor neutron flux and assayed by photon spectroscopy. The surrogate transuranic (TRU) waste material was contaminated with Pu-238 simulants and loaded into the cleaning chamber, where the surrogates were ultrasonically agitated and rinsed. The decontaminated materials were then assayed for surface contamination by DPA to establish optimum operating parameters and provide process quality control. Selected samples were sent to the Massachusetts Institute of Technology for neutron activation analysis (NAA). NAA testing resulted in weighted average decontamination factors (DFs) in the range of 125 to 157 for the surrogate waste mixtures. The weighted DFs for the organic portion of the surrogate waste mixtures ranged from 66 to 140. The NAA DF for inorganic material was 370. Other than the removal of particulate contamination, the processed samples were unchanged by decontamination. Most NAA samples were irradiated after decontamination. However, several samples were irradiated in the reactor core prior to decontamination in order to investigate the possible interference of radiation induced imbedding of particles in organic materials. The radiation dose was in excess of 110 Mrad. The NAA DF for samples irradiated before decontamination was six.