Assessment of Physical Properties of Transuranic Waste in Hanford Single-Shell Tanks

Rassat, Scot D. ; Mahoney, Lenna A. ; Wells, Beric E. ; Mendoza, Donaldo P. ; Caldwell, Dustin D.

Pacific Northwest National Laboratory (U.S.)

关键词: Transuranic Waste;    Hardness;    Wastes;    Physical Properties;    Tanks;   

DOI  :  10.2172/15010113
RP-ID  :  PNNL-14221
RP-ID  :  AC05-76RL01830
RP-ID  :  15010113

美国|英语

来源: UNT Digital Library

【 摘 要 】

CH2M HILL Hanford Group, Inc. (CH2M HILL) is in the process of identifying and developing supplemental process technologies to accelerate the tank waste cleanup mission. One technology targets disposal of Hanford transuranic (TRU) process wastes stored in single-shell tanks (SSTs). Ten Hanford SSTs are candidates for designation as contact-handled TRU waste type: the B-200 series tanks (241-B-201, -B-202, -B-203, and -B-204), the T-200 series tanks (241-T-201, -T-202, -T-203, and -T-204), and Tanks 241-T-110 and T-111. Current plans identify a process in which these wastes are retrieved from the tanks, either dry or with a recycled liquid stream to help mobilize the waste in the tank and through transfer lines and vessels, dewatered to remove excess liquid, and transferred to waste packages in a form suitable for disposal. CH2M HILL seeks to procure a process for dewatering, handling, and packaging the contact-handled TRU waste after it is retrieved. An understanding of waste physical properties is needed to support design of the SST TRU handling and packaging system and to produce suitable physical simulants to test such a process. Pacific Northwest National Laboratory (PNNL) has been tasked with developing these waste simulants. This report summarizes PNNL's assessment of available waste physical property information for the 10 candidate TRU SSTs. Data sources include the Hanford Tank Waste Information Network System (TWINS) database, technical reports, and visual observations from the review of photographs and videotape recordings taken during the extrusion of various SST TRU waste core samples. While the retrieval process is expected to alter certain waste physical properties such as shear strength, the effects of this process on waste properties cannot yet be quantified. Therefore, the scope of this report is to describe the properties of SST TRU wastes as they are known for unprocessed wastes or, in some cases, for diluted waste samples. The report focuses on the waste rheology, settling characteristics, particle properties, bulk density, and water content. Because some physical properties of the waste are related to the waste chemistry (e.g., particle hardness), a brief overview of the process and chemistry resulting in the TRU waste is provided. Other properties, including the potential for gas retention in the waste, are discussed briefly. Qualitative descriptions of how waste properties might be affected by retrieval and subsequent processing are also noted.