Panel supports expansion of vit plant

Expansion of the $12.3 billion vitrification plant would be the surest bet for treating radioactive waste that the plant as now designed can't treat in a reasonable amount of time, an expert panel commissioned by the Department of Energy has concluded.

Other options include bulk vitrification, improving efficiency of the main vitrification plant and an early start-up of part of the main vitrification plant that would treat low-activity radioactive waste.

However, the panel said a decision on how to treat the excess waste could be delayed until 2017. That would give DOE more time to resolve some technical issues.

When DOE started considering options for treating the rest of the waste, the vit plant was expected to be operating in 2011. But now that's been pushed back to 2019 and technical questions that could affect plant's capacity remain unanswered.

DOE should focus now on getting the vitrification plant operating by 2019 and making sure systems are in place to reliably retrieve waste from storage tanks and transfer them to the vit plant, the panel said.

Further development of bulk vitrification should not be given a high priority, the panel said.

The vitrification plant, formally called the Waste Treatment Plant, is being built to treat 53 million gallons of radioactive waste now held in underground tanks. That includes waste in 142 leak-prone single-shell tanks that is being transferred into sturdier double-shell tanks, which are running out of space with no method yet available to treat the waste.

The waste, which will be split into high-level and low-activity radioactive waste streams, is left from the past production of plutonium for nuclear weapons.

The vit plant was originally planned as one of two facilities to turn the tank wastes into a stable glass form for disposal. But in 2003 DOE decided that rather than building a second plant it could enhance the plant to treat all of the high-level radioactive waste.

However, the plant still could treat only about half the low-activity waste and DOE has been looking at options for treating the rest of that waste.

DOE now does not know exactly how much low-activity waste will need to be treated. Its priority is to reduce the quantity of high-level radioactive waste, which includes adding sodium to dissolve nonradioactive aluminum so it is not filtered out with high-level radioactive waste solids.

But the more sodium is added, the more the volume of the low-activity waste stream will increase. That means DOE does not know how much additional capacity it will need for treating low-activity waste.

To make sure DOE does not spend more than it must on supplemental treatment development, it needs a clear idea of how much waste will need to be treated, said Steven Krahn, DOE director of the Office of Environmental Management's Office of Waste Processing.

Current estimates appear to be high, the report said. It recommended a second top priority for DOE should be developing ways to reduce the addition of sodium and therefore the amount of waste.

The panel favored adding a second low-activity waste facility to the vitrification plant as the best option for treating the excess low-activity waste based on what's known today. It's "low risk" because the base technology is mature and well understood, the report said.

However, it also recommended DOE consider upgrading the single low-activity waste facility now under construction to treat all low-activity waste if sodium additions can be controlled. Although DOE has wanted to complete waste treatment in 30 years, the waste possibly could be treated in 36 years by upgrading the facility.

The panel also looked at an early start to treatment of low-activity waste because the low-activity waste facility could be finished years before the high-level waste facility. That would demonstrate progress in treating waste and free up double-shell tank space, but the panel questioned whether the low-activity facility could begin operating long enough before the rest of the plant to justify extra costs.

The final option for supplemental treatment, bulk vitrification, would glassify large amounts of waste into glass blocks the size of a land-sea shipping container.

"The testing of this technology and the design of a demonstration system support fewer advantages of this technology over other potential supplemental treatment alternatives than previously thought," the report said.

Given the need for a selection of a technology by about 2017 and uncertainties about sodium inventory, bulk vit should not be given a high priority, it said. Critical issues in its development remain, the report said.

The Washington State Department of Ecology had just received a copy of the report Monday and was starting its review.

But the state has long recommended a second low-activity waste facility be added to the vit plant, said Jane Hedges, nuclear waste program manager for the state. While it has supported investigation of other technologies such as bulk vitrification, it considers adding a second facility the option with the most proven technology and results.

The state wants to make sure the final decision on treatment for low-activity waste does not add to delays and would strongly support options that would shorten the treatment time, she said.