A view of the redesigned auger-grinder before the recent demonstration.

A view of the redesigned auger-grinder’s head following the recent demonstration.

IDAHO FALLS, Idaho – A redesigned facility component operated successfully during recent testing, representing a key step in the commissioning of the Integrated Waste Treatment Unit at EM’s Idaho Site.

  A new, prototype auger-grinder worked as designed in the treatment of about 18,000 gallons of simulant material during a demonstration in March. IWTU engineers redesigned the auger-grinder late last year after it didn’t work correctly in a previous waste demonstration. Located at the bottom of the Denitration Mineralization Reformer (DMR), the IWTU’s primary waste treatment vessel, the auger-grinder breaks up clustered material and transfers treated waste product to the waste canister filling system. In the latest demonstration, the auger-grinder transferred the material to storage canisters reliably and consistently.

   Earlier testing focused on keeping the redesigned auger-grinder above a threshold temperature and enabling a suitable gaseous atmosphere to avoid cementation to ensure proper product transfer. This design included a more powerful variable speed drive motor, new grinding head and larger clearances that aid in the transfer of the granular product. 

   The IWTU is intended to treat the approximately 900,000 gallons of liquid waste remaining in an underground tank farm at the Idaho Site. The next planned demonstration will center on improving chemical and mechanical fluidization properties in the DMR. Testing on DMR-scaled models with simulated waste continues at Hazen Research near Golden, Colorado. The industrial research facility works with EM’s Idaho Cleanup Project contractor Fluor Idaho, Idaho National Laboratory and other engineering project teams to improve the movement or fluidization of treatment media and waste product in the DMR.

   In the next demonstration, IWTU engineers are set to install a new heater and associated piping to introduce carbon dioxide and nitrogen gases inside the lower portion of the DMR. That addition will improve the distribution and control of gases within the DMR to aid the chemical reactions and fluidization of media and granular waste product.