Washington and Oregon officials agreed Tuesday that concrete-like grout could be used instead of glass to solidify a significant portion of Hanford’s radioactive liquid waste, as long as the grouted waste is taken off-site.
Suzanne Dahl, tank waste manager for the Washington Ecology Department and Matt Hendrickson, her counterpart at the Oregon Department of Energy, each said they are receptive to using grout to tackle part of the low-activity wastes at Hanford.
The two spoke during a webcast briefing from Richland, Wash., near Hanford, during which National Academies members discussed their review of a DOE-chartered report, Review of the Continued Analysis of Supplemental Treatment Approaches of Low-Activity Waste at the Hanford Nuclear Reservation: Review #3.
Both officials said they are against burying grouted wastes at Hanford because grout is more likely to decay and break up than waste that is solidified in a glass-like substance at Hanford’s Waste Treatment and Immobilization Plant.
Hanford’s potential burial sites are over an aquifer that leads to the Columbia River. The long-range plan for the glassified low-activity wastes is for the material to be buried at Hanford. Low activity waste makes up the bulk of the tank waste at Hanford, though it contains far less radioactivity than high-level waste. All the waste is a byproduct of Manhattan Project and Cold War plutonium production for nuclear weapons.
Under current cleanup deadlines, glassification of the high-level radioactive tanks wastes is not expected to begin for one or two decades. That waste will be transferred off-site to a destination that is still undetermined; it was supposed to go to somewhere like the proposed Yucca Mountain high-level waste repository, but that facility remains undeveloped and without a clear path to approval.
The state officials also said Tuesday that more environmental studies should be made of potential grout options and that the public should be briefed on, and should have a role in choosing, such options.
If DOE decides to use grout at Hanford, that effort would run parallel the first scheduled round of low-activity waste glassification in the Waste Treatment and Isolation Plant which is due to begin by 2025.
Without grouting, the NAS report concluded that glassifying Hanford’s 56 million gallons of wastes, stored now in 177 underground tanks, might continue beyond 2090. With grouting, the report concluded all the wastes could be treated by 2068.
Originally, the legal deadline to complete glassification was 2019. Currently, the federal consent order governing cleanup at Hanford calls for glassifying all liquid tank wastes by 2052.
However, Washington State, DOE and the Environmental Protection Agency, the other federal agency with jurisdiction over Hanford cleanup, have reached an agreement in principle on a new cleanup schedule after years of what they called “holistic talks.”
The parties had not unveiled the details of the agreement as of Wednesday.
