The first module of a test system for Hanford's massive vitrification plant arrived in Richland this week in an oversize truckload.

It will be part of the Pretreatment Engineering Platform, a complex the size of a basketball court and standing up to 18 feet high, that will be assembled in a building on the Battelle campus in north Richland.

The Department of Energy and vit plant contractor Bechtel National plan to use the test platform to answer some key technical questions about how efficiently the $12.2 billion vitrification plant will separate radioactive waste into high-level and low-activity waste streams in its Pretreatment Facility. The plant is planned to turn millions of gallons of waste left from the past production of plutonium for the nation's nuclear weapons program into a solid glass form starting in 2019.

In 2006 an independent technical review of the vit plant questioned whether enough was known about how nonradioactive aluminum would be separated from other solids that are high-level radioactive waste.

The aluminum separations process, which uses filters, has worked in the laboratory on cupfuls of radioactive waste. But at the vit plant the process must be scaled up to 80,000-gallon tanks of radioactive waste.

The test platform will replicate key separation processes planned at the vit plant at a scale of 1 to 4.5 in a project budgeted to cost $125 million including building and operating the test platform.

If aluminum is not removed from the waste, the plant will produce double the amount of waste canisters of glass logs that would need to be disposed of in a national repository at Yucca Mountain, Nev. Removing the aluminum could reduce the number of high-level waste canisters to 12,000 to 14,000, said John Eschenberg, the Department of Energy project manager.

Producing fewer glass logs would reduce the years the vit plant will have to operate, because the high-level logs take longer to make than the low-activity logs that will be disposed of at Hanford.

To remove the aluminum from the radioactive solids, DOE plans to add sodium hydroxide to dissolve it into a liquid. Then the slurry will be sent through ultrafilters that should concentrate the solids - which are primarily high-level radioactive waste - but should not capture the aluminum dissolved in the liquid.

However, adding more sodium hydroxide will increase the volume of low-activity waste produced. Under the worst-case scenario, it could increase the low-activity volume by up to 40 percent, Eschenberg said.

"For the first time, we will be able to test it on a large scale and it will tell us how much sodium we will have to add," he said. "We may not have to add as much as we thought."

The test platform also will answers questions about how quickly the ultrafilters can concentrate the waste. If the ultrafilters are too small, separate batches of waste will have to be sent through in a time-consuming process.

"It affects the overall length of vitrification plant operation," Eschenberg said. "It's a pinch point."

In 2006 the waste was planned to be sent through a series of three 8-foot filters. Since then the design has been changed to bring the total length of the filters to 46 feet, using all available space in the Pretreatment Facility.

"We need to prove the length of the ultrafilters is adequate," Eschenberg said.

The high-level radioactive waste will include cesium, strontium and actinides such as plutonium. The low-activity waste will include lower amounts of cesium and other mixed fission products, as part of a legal definition system that relies on where in the production cycle the waste was generated.

DOE expects to start tests using the Pretreatment Engineering Platform by the end of the year and complete the tests by the end of 2009. The schedule has slipped because of delays in fabricating the platform, Eschenberg said.

The pieces of the test platform are being manufactured in Carlsbad, N.M., by Washington Group International's Engineering Products Division, which is part of URS Corp., and Tessenderlo Kerley Services.

Sixteen modules will be shipped as oversize truckloads to Richland and about 20 smaller loads also will be sent. They should arrive through April.

The modules will be installed and tested by Pacific Northwest National Laboratory and subcontractors.