A shipment of waste from Hanford to a permanent repository in New Mexico was stopped Friday in Colorado because one of the drums of waste may have been too radioactively hot.
Dec. 14A shipment of waste from Hanford to a permanent repository in New Mexico was stopped Friday in Colorado because one of the drums of waste may have been too radioactively hot.
It's the first time any shipment has had a drum with a radiation reading too high to be accepted at the Waste Isolation Pilot Plant a permanent underground repository for transuranic waste in the New Mexico desert, said Kerry Watson, the Department of Energy director for the office of characterization and transportation in Carlsbad, N.M.
The drum had been measured at Hanford with a combined beta and gamma radiation reading at the surface of the drum of 200 millirems per hour. No neutron radiation reading was detected.
But because instruments cannot detect radiation below 0.2 millirems per hour, there could have been a neutron dose of up to 0.2 millirems, Watson said.
That would have put the overall radiation dose slightly above the maximum allowed of 200 millirems per hour.
"We couldn't say it would. We couldn't say it wouldn't," Watson said.
The possible problem was discovered when paperwork was being inspected in New Mexico as the shipment was already en route, Watson said.
A truck carrying two shipping containers that hold up to 14 drums each was stopped near Fort Collins, Colo. The truck returned Saturday to Hanford.
Another survey of the drum's radiation levels on Sunday again found 200 millirems per hour of beta and gamma radiation and an undetectable level of neutron radiation, said Colleen French, spokeswoman for the Department of Energy in Richland.
The drum contains transuranic waste, which typically is used equipment, protective clothing or other debris contaminated with plutonium. The waste in the drum came from the Plutonium Finishing Plant and the PUREX reprocessing plant at Hanford.
The PUREX plant was used to extract plutonium from fuel irradiated in Hanford reactors for the nation's nuclear weapons program. The Plutonium Finishing Plant turned the plutonium into metal buttons to ship to the nation's weapons production plants.
Officials at Hanford and WIPP, the New Mexico repository, are discussing what to do with the rogue drum and how to prevent the problem from occurring again, French said.
The drum may be repacked, or it could be encased in an overpack to reduce the radiation dose at its surface, she said.
Before being loaded onto trucks, the drums are packed into a shipping container, called a TRUPACT-II, that has substantial radiation shielding, she said.
"There was never any health or safety concern" for the public en route, she said.
At the surface of the shipping container, 0.5 millirems per hour of beta and gamma radiation was detected. That's far below the U.S. Department of Transportation limit, which also is 200 millirems per hour.
The returned shipping containers are being held at Hanford, awaiting approval to ship them again. Hanford has shipped 3,838 drums in 124 shipments to WIPP since 2000. The returned shipment would have been the 125th.
"Two more shipments are scheduled this week, so it's even more important to get this resolved," French said.
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Â© 2004, Tri-City Herald, Kennewick, Wash. Distributed by Knight Ridder/Tribune Business News.