The Department of Energy's new cost and schedule plan for Hanford's vitrification plant ought to be more definitive than the last one.
No offense to the previous effort, but the team working on the new study has an additional five years worth of experience to draw on, including what's gone wrong in the interim and how much it has cost.
There's no telling how much the new estimate might alter expectations when it comes out in August, but the last attempt to define the cost and schedule produced radical changes in the game plan.
When that exercise was completed in 2006, the estimated price tag more than doubled, from $5.5 billion to $12.2 billion, and the expected start of operations went from 2011 to 2019.
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But while the new study should decrease uncertainty, it won't eliminate it. Some level of uncertainty will remain with the vitrification plant until operations are complete and decommissioning is done.
The August report isn't the only potentially game-changing revision on the horizon.
The safety basis, which identifies possible accidents or other mishaps and finds ways to prevent them, also will be revised.
It's a key document that not only helps the plant's design staff protect public safety and keep the facility running, it also effectively serves as a license to operate.
In addition, Bechtel National has launched a major initiative to improve safety culture at the project.
During the Defense Nuclear Facilities Safety Board meeting in Richland last week, chairman Peter Winokur identified strengthening the safety culture as essential to resolving technical issues concerning the safe operation of the plant.
With the plant more than half built and the design 85 percent complete, it might seem late in the game to be resolving questions about cost, schedule and the safe operations of the plant.
But despite the drawbacks, the existing construction system is likely superior to the alternatives for this massive and complex project.
If the project had started with design, gone to bid and finally to construction -- the way a house might be built -- then it's probable the start of construction still would be months or years away.
There is no design to copy or modify. The task at hand -- turning Hanford's unique mix of 56 million gallons of toxic and radioactive liquids into glass logs -- is the most complex environmental project ever tackled.
That's not a reason to take shortcuts that could jeopardize the safe operation of the plant or the public's safety, but it's important to view the project in a realistic context.
The technical questions that are plaguing the project these days center around serious issues.
Will corrosive and erosive materials in the wastes wear through the process tanks used in the glassification?
Is there any danger that hydrogen gas in the wastes might explode inside the process tanks?
Is there a risk of plutonium going critical inside the tanks?
The risk to the public from any of these issues is virtually nil. The concrete and steel walls that house the facility can withstand any of these events.
But the cost and complexity of cleaning up after a failure inside one of the plant's black cells would be staggering. Any remaining wastes would be left untreated.
Resolving the technical issues may push the start date out even farther, a concern that prompted Sen. Patty Murray to grill Energy Secretary Steven Chu at a recent hearing of the Energy and Water Development Appropriations Subcommittee.
"You are quite right to be concerned," Chu admitted.
More needs to be done to resolve the technical issues and improve safety culture at the project. But we can't wait for absolute certainty.
Some risk will always be inherent in the operations of the vitrification plant. The job is too complex and dangerous to be otherwise.
But that has to be balanced with the risk of catastrophic failure of one of the underground tanks where the wastes have been "temporarily" stored for decades.
That risk, given enough time, is 100 percent.