RICHLAND, Wash. – The caustic scrubber for the EM Office of River Protection’s Waste Treatment and Immobilization Plant’s (WTP) Low-Activity Waste (LAW) facility has been installed, paving the way for completion of the facility’s construction in 2018.  

   “This is the last major piece of equipment to be installed in the facility,” explained the LAW facility federal project director Jeff Bruggeman. “This allows for us to continue moving forward towards construction complete to support the direct feed of low-activity waste.”

   Workers recently installed the nearly 29-foot-tall and 6-foot diameter caustic scrubber to remove contaminants from the off-gas exhaust created during vitrification of low-activity waste. 

   “The caustic scrubber removes acid gases and nitrogen oxide components in the off-gas generated from the melters,” said Bruggeman. These components, he said, are harmful to people and the environment.   

   Installing the scrubber’s internal parts and supporting wiring, piping and other connections to the off-gas treatment system will continue into early next year, according to Bechtel National, ORP’s prime contractor for building the facility.

   At the LAW facility, the majority of Hanford’s chemical and nuclear tank waste will be mixed with glass-forming materials, heated to 2,100 degrees Fahrenheit in melters. The resulting molten material will be poured into containers, where it will cool and harden into a solid glass form.   

   As the material is heated, gases are released. The off-gas system, of which the caustic scrubber is part, will remove contaminants from these gases before being exhausted from the facility stack at levels that meet environmental, safety, and health requirements.