Vit Plant Completes Critical LOOP Test

The Vit Plant has successfully completed a loss of offsite power (LOOP) commissioning test, a critical step toward the heatup of melters and vitrification of Hanford’s radioactive and chemical tank waste for disposal.

When offsite power was cut during the test, plant personnel activated backup power to keep critical safety systems operational while they worked through procedures to restore power to the plant.

“Our proficiency in responding to a LOOP is important, because during 24/7 plant operations, each of our shift crews needs to be able to respond appropriately,” said Rick Holmes, general manager for the Waste Treatment Completion Company, a subcontractor to project lead Bechtel National, Inc. “They need to place the plant in a safe configuration and restore power to the melters to ensure they stay at their operating temperature.”

Offsite power is provided to the plant by infrastructure that is managed by contractor Hanford Mission Integration Solutions (HMIS). To “cut” offsite power, HMIS remotely opened the primary power supply breaker to the plant and then closed it once the test was completed.

The ability to restore power to the plant is critical. Two melters inside the plant’s Low-Activity Waste (LAW) Facility will immobilize radioactive and chemical waste in a glass form. Once a melter has reached its operating temperature of 2,100 degrees Fahrenheit, it must remain at temperature for its entire lifespan. If a melter were to cool and the glass inside became solid, the melter would need to be replaced. The first melter will be brought up to temperature in the next few months.

“Achieving this milestone brings us a significant step closer to initiating melter heatup,” said Mat Irwin, ORP deputy assistant manager for the plant. “The training has paid dividends and brings us one step closer to vitrification.”

The entire Hanford Site is preparing for a shift to 24/7 operations by the end of 2023, when vitrification of tank waste is scheduled to begin as part of EM’s Direct-Feed Low-Activity Waste (DFLAW) Program. The DFLAW Program is a system of interdependent projects and infrastructure improvements, managed and highly integrated, that must operate together to vitrify the waste.

During vitrification, waste treated to remove radioactive cesium and solids at a tank farm will be fed directly to the LAW Facility’s melters. The waste and glass-forming materials will be mixed, heated, and poured into specially designed stainless-steel containers. The containers will be transported a short distance to the site’s Integrated Disposal Facility for disposal.

The 300-ton Hanford melters are each four times larger than the one in operation at EM’s Defense Waste Processing Facility at the Savannah River Site in South Carolina. Hanford’s LAW Facility is designed to vitrify 5,000 gallons of low-activity waste a day — or 1.75 million gallons a year — when operating at full capacity.

Contact: Staci A. West, 509-378-0308 or sawest@bechtel.com