The 65-ton vessel arrives in Richland.

RICHLAND, Wash. – A 65-ton vessel critical to determining the safe mixing and processing of radioactive waste at EM’s Office of River Protection Waste Treatment and Immobilization Plant (WTP) arrived here this month.

   Testing will be conducted on the vessel to determine mixing performance using nonradioactive materials that are simulants of the actual waste stream. Proper mixing is required to safely process and treat the waste at WTP’s Pretreatment Facility.

   The test vessel is a full-scale prototype of several vessels expected to be used to process liquid radioactive waste containing solids. EM contractor Bechtel National is building WTP. When complete, the plant will vitrify most of the 56 million gallons of the country’s most complex nuclear waste currently stored in tanks on the Hanford Site.

   The vessel was barged up the Columbia River from Vancouver, Wash. Greenberry Industrial fabricated the vessel at its manufacturing facilities in Vancouver and Corvallis, Ore. It will be loaded into the Full-Scale Vessel Test Facility in Richland through the roof and placed in a specially designed test stand. Reassembling the test stand and completing preparations for testing will take several months. The year-long testing program is expected to begin in late 2016.

Testing Process

   Critical to mixing performance are the pulse-jet mixers inside the vessel. They work much like turkey basters — withdrawing fluid and expelling it — mixing vessel contents in the process. 

   Testing is being conducted to confirm the mixers and associated control systems meet their mixing functions. Hanford’s radioactive liquid tank waste has a wide-range of chemical and physical characteristics that present unique challenges in mixing tank waste.

   To conduct the tests, non-radioactive fluid and particulate material, simulating the Hanford tank waste, will be added to the vessel. Once this simulated waste is added, the vessel’s operating weight will be 310 tons. 

   Previous tests using a smaller vessel confirmed that control equipment can reliably operate the mixers. The new vessel will be used to test the equipment at full scale.

   The 35-foot high by 16-foot diameter stainless steel test vessel has a volume of 22,000 gallons, equivalent to 2.5 tanker trucks.

   Test results will be used to support technical decisions that have slowed construction on the Pretreatment Facility.