Hanford’s new plan to clean up 56 million gallons of nuclear waste

The first low-activity-waste glassification plant is expected to handle only 40% to 50% of the low-activity wastes, depending on who is doing the estimating. That means it is likely another plant will need to be built, unless another solution takes its place. Meanwhile, glassification of high-level wastes is also expected to begin in the next decade, said state ecology department spokesman Ryan Miller.

Adding grouting to the solution list may help

The GAO has been gung-ho about grout. Since 2017, the GAO issued three reports strongly recommending that the DOE look at replacing the second low-activity-waste glassification plant with a plan to grout the roughly 50 percent of low-activity wastes not handled by the first low-activity plant. Grouting is theoretically faster and cheaper than glassification. 

Washington officials have always been skeptical about grout, citing its lack of a track record with the types of wastes found in Hanford’s tanks. DOE has been close-mouthed in the past about its preferences.

Monday’s tentative agreement calls for grouting to be used on low-activity wastes found in 22 tanks that also contain high-level wastes. A decision on grouting technology — which will then lead to budgeting and scheduling — is due by the end of this year.

Meanwhile, all 149 single-shell tanks and the majority of the 28 double-shell tanks are way past their design lives. So far, only one double-shell tank has sprung a leak in its inner wall, and thus can no longer be used.

The 2021 GAO report said DOE believes there is a 95% chance that Hanford will run out of space in its 27 remaining double-shell tanks before the next steps happen. If leaks occur in more double-shell tanks, that could delay glassification by several years and create further problems. It would take seven years and $1.5 billion to build four million-gallon double-shell tanks, the GAO reported. Since 2018, the Hanford Advisory Board has been pushing DOE to get started on this contingency plan.

Monday’s announcement calls for Hanford to add 1 million gallons in tank space by 2040. It has not been decided yet whether that will be one big tank or a group of smaller tanks.

There are also calls to revamp some of the piping system that sends waste from the tanks to the glassification plants, and to redesign the approach for processing wastes before they enter the future high-level waste-glassification facility.