Ground work for significant Hanford cleanup is laid out for decades to come in a draft version of a massive new environmental study of Hanford released in the Tri-Cities on Monday.
Among decisions it recommends are entombing Hanford's Fast Flux Test Facility, emptying 99 percent of waste from underground tanks, leaving the emptied tanks in the ground, and continuing to ban some, but not all, radioactive waste from being sent to Hanford.
The Draft Tank Closure and Waste Management Environmental Impact Statement is more than 6,000 pages and has been in the works since 2003. Topics it covers have been expanded several times in that time.
The draft study will be the basis for a final study and followed by decisions by the Department of Energy.
The draft study considered three options for FFTF, a shutdown 400-megawatt research reactor that supporters say is DOE's largest and most modern reactor. Work has been under way to deactivate it to a state that will require a minimum of maintenance short of tearing it down.
Now DOE is considering whether to leave FFTF as is, entomb it or remove it. Restart is not considered a reasonable alternative, the study said. "There are currently no proposed uses," it said.
The draft study recommends the reactor building be torn down above-ground and that underground structures, including the reactor vessel, be filled with grout to immobilize remaining radiological and other hazards.
Some radioactive components with residual sodium would be sent to the Idaho nuclear site for treatment and then returned to Hanford for disposal.
The draft study also makes good on a promise DOE made to the state of Washington in a proposed settlement of a lawsuit over missed legal deadlines for emptying underground tanks and treating their waste. The draft study recommends a ban on importing certain types of wastes be extended until the vitrification plant is treating radioactive tank waste by melting it into glass form, which is projected for 2022.
The recommendation appears to meet the state's conditions in the proposed settlement. It would ban Hanford from being used to dispose of ordinary low-level radioactive waste, some of it mixed with hazardous chemicals, that was created elsewhere. It also would prevent DOE from sending transuranic waste -- usually debris contaminated with plutonium -- to Hanford for storage.
The state asked that the ban until about 2022 cover radioactive wastes that DOE had already announced it planned to send to Hanford. But the ban would not cover wastes that DOE is considering whether to send to Hanford.
Separate decisions are pending on where to send the nation's surplus mercury and its greater-than-class-C low-level radioactive waste, which includes commercial and nonweapons waste that is among the most radioactive waste that still can be classified as low-level.
The study also considers options for emptying leak-prone underground tanks, what to do with emptied tanks and how to treat the waste.
It leaves an array of options with no recommendation for treating low-activity tank waste after it is separated from high-level tank waste. The $12.3 billion vitrification plant was not planned to be large enough to treat all the low-activity waste in a reasonable time.
DOE continues to consider expanding the vitrification plant or using an alternate treatment such as bulk vitrification.
The state said in its response to the study that it favors expanding the vitrification plant by adding additional capacity for low-activity waste.
"Vitrification is a mature technology that is ready to be implemented with no further testing," the state wrote. "(It) produces a well-understood waste form that is extremely protective of the environment."
The study compares benefits of removing 99 percent of the waste in Hanford's 147 leak-prone single-shell tanks or just removing 90 percent. The Government Accountability Office recently questioned if the 99 percent standard, which is required in the legally binding Tri-Party Agreement, had a scientific basis.
The study recommends removing 99 percent of the waste, finding that would best protect ground water.
Emptied tanks would be left and filled with grout under the study recommendation. The alternative of removing the emptied tanks, cutting them up and disposing of them in a Hanford burial ground presents technical challenges and risks of radiation exposure to workers and radioactive releases into the air, said Mary Beth Burandt, DOE document manager on the project.
Discussion of the draft study will further narrow alternatives for several topics, such as how to treat the remainder of the tank waste. Specific recommendations are expected in the final study.
DOE is accepting comments on the study from Friday until March 19. Comments may be sent to Mary Beth Burandt, EIS Document Manager, DOE Draft TC&WM EIS Comments, Office of River Protection, P.O. Box 1178, Richland, 99352. Comments also can be submitted via e-mail at TC&WMEIS@saic.com, and public meetings will be scheduled.
The study is posted online at tinyurl.com/ykasuud.
-- Annette Cary: 582-1533; email@example.com; more Hanford news at hanfordnews.com.