Jun. 07, 2011

By Annette Cary

From the Tri-City Herald

Deep geological disposal is the best alternative for the nation's waste classified as greater than class C low-level radioactive waste and similar nondefense waste, according to the Hanford Advisory Board.

The HAB board has joined several other agencies or groups in recommending Hanford be taken off a list of locations the Department of Energy is considering for disposal of the waste. The states of Washington and Oregon already have asked that Hanford be taken off DOE's list.

At Hanford the waste would be disposed of in trenches, vaults or boreholes. The nation's only deep geological repository -- now that the Yucca Mountain, Nev., repository is not moving forward -- is the Waste Isolation Pilot Plant in New Mexico.

However, DOE has agreed to use the New Mexico site only for defense radioactive waste, which would exclude the greater than class C waste. That nondefense waste includes some waste similar to what Hanford now sends to New Mexico.

DOE is considering what to do with 190,000 cubic feet of such wastes stored around the nation, plus 340,000 cubic feet of waste expected to be generated in the next 60 years.

The waste has a high radioactivity of about 160 million curies. In comparison, the 53 million gallons of waste awaiting treatment in Hanford underground tanks have about 190 million curies and the worst of that was to be disposed of in a deep geologic repository.

Much of the radioactivity in the waste being considered to be sent to Hanford is in activated metals from nuclear reactors being decontaminated or decommissioned. It also includes concentrated radioactive materials used medically for diagnosing and treating cancer.

The advisory board believes Hanford is one of the leading alternatives DOE is considering.

But the board has consistently advised against disposal at Hanford of additional waste from elsewhere, the board said in its advice to DOE.

"Under current proposals for disposing of existing Hanford wastes, ground water standards at Hanford will be exceeded for thousands of years," the board told DOE. "Acceptance of additional wastes from offsite would greatly increase and compound those already identified impacts."

The draft Hanford Tank Closure and Waste Management Environmental Impact Statement looked at the environmental effects of waste already planned to be disposed of at Hanford. Those impacts should be included in the greater than class C waste study using the more sophisticated modeling for waste migration and radioactivity in the Hanford draft study, the board said.

DOE has agreed not to send more waste to Hanford until at least 2022. At that time a new environmental study should be done with public comment if Hanford still is being considered, the board said.