A couple of recent events at Hanford have raised our anxiety level.
First, we learned that measurements appear to show that the level of radioactive wastes in 52 of Hanford's underground tanks is rising.
The reason is a mystery, but it's possible that precipitation is getting into some of the waste tanks, raising concerns about the integrity of the steel shells.
Less alarming scenarios are possible. The surface of the tank wastes can be rough, with peaks and valleys inside the tanks. If measurements were taken in different spots, the discrepancies may reveal nothing more than the uneven nature of the wastes.
Hanford stores 56 million gallons of high-level radioactive and hazardous chemical waste left from the production of weapons plutonium.
The tank farms have 28 newer double-shell tanks and 141 older single-shell tanks, some of which have leaked in the past.
An assessment of routine measurements of the single-shell tanks concluded that levels may be rising in 52 of the tanks, with changes ranging from a couple thousands of an inch a year up to an average of about three-quarters of an inch a year.
More testing needs to be done to determine why the measurements have changed over time, but even a reassuring explanation wouldn't justify complacency.
The cause behind the phenomenon might be a mystery, but the eventual fate of Hanford's tanks is not. Every one will fail, some of them catastrophically. The combined effects of gravity and corrosion make that a certainty.
It's why the other big news out of Hanford in recent weeks makes us uneasy.
The Department of Energy has decided to delay calculating a new cost and schedule for Hanford's vitrification plant until more technical issues are addressed.
Any delay in the start of operations means it will be that much longer before tank wastes begin to be turned into glass logs for permanent disposal.
It's essential to resolve questions about plant design and construction that could affect the safety and reliability of operations at the plant.
But it's impossible to remove all risk from the enterprise. The desire for perfection must be balanced against the certainty that failure to treat the tank wastes would lead to an environmental disaster for the entire Northwest.
DOE is preparing for large-scale tests to make sure waste in the plant's tanks will remain adequately mixed and that the plant can withstand the effects of erosion and corrosion.
It's understandable that DOE wants to await results of these critical tests before producing a new cost and schedule. The results could significantly alter both estimates.
But we worry that Congress could start looking for reasons not to continue footing the bill for construction.
Resolving the remaining technical issues and producing some reliable estimates for cost and schedule are imperative.
It's just as urgent to study the way technical issues have been addressed at the vit plant and adopt any lessons learned.
Of particular importance is whether concerns raised by employees could have been handled more effectively. Whether delays in addressing corrosion concerns, for example, further complicated efforts to revise the vit plant's cost and schedule is an important question.
Efforts are under way to improve the safety culture at the plant and ensure legitimate issues are resolved. Indications are that the effort is meeting with some success.
That's encouraging but it's a process that won't be complete as long as construction is under way.
The mystery at the tank farms is a stark reminder of why success is the only option.