A section of the thermal catalytic oxidizer is lowered into the LAW facility.

RICHLAND, Wash. – Workers recently completed installing two of the last major pieces of equipment for the EM Office of River Protection’s Low-Activity Waste (LAW) Vitrification Facility at the Hanford Site’s Waste Treatment and Immobilization Plant (WTP).

   Installation of the thermal catalytic oxidizer and ammonia dilution skid is a major element in completing construction of the LAW facility.

   Critical to the safe treatment of waste, the 60-ton thermal catalytic oxidizer and 7-ton ammonia dilution skid are part of the system that will remove toxic contaminants from the low-activity radioactive waste glass melter exhaust.

   Called the off-gas system, it is needed to ensure the exhaust meets regulatory requirements for release to the environment.

   “The fabrication, delivery and installation of the significant pieces of off-gas equipment are the culmination of several years of hard work from a team of engineering, procurement and construction professionals and marks a significant milestone toward completing the LAW Facility,” said Scott Neubauer, Bechtel National, Inc.’s LAW area project manager. Bechtel is ORP’s contractor for WTP.  

   Ionex Research Corp. fabricated and tested the thermal catalytic oxidizer and ammonia dilution skid in its facilities in Lafayette, Colo.

   The caustic scrubber, the final piece of the off-gas system and last major piece of equipment to be installed in the LAW, will be received later this year.

   The off-gas system will convert volatile organic compounds to carbon dioxide and water vapor, convert nitric oxide to hydrogen and oxygen, remove acidic gases from the exhaust and cool the exhaust before releasing it through the stack.

   When the LAW facility is operational, it will convert into glass more than half of the liquid, low-activity radioactive waste removed from Hanford’s 177 underground tanks. The treatment process is called vitrification and involves mixing the waste with glass-forming materials and heating them in a melter to 2,100 degrees F.

   The molten glass will be poured into containers, where it will be allowed to cool, immobilizing the waste in solid glass, and sent to an engineered landfill for disposal.