Hanford workers have unearthed 32 whole and 11 partial pieces of highly radioactive reactor fuel in burial grounds for reactor debris along the Columbia River.

They are certain to find more, as digging is in progress or to begin at seven of the Hanford nuclear reservation's 11 major burial grounds for reactor debris.

"This shows why Ecology, and also the Environmental Protection Agency and the Department of Energy, wants the burial grounds dug up," said John Price, environmental restoration project manager for the Washington state Department of Ecology.

When pumps, tongs, the spacers used between fuel pieces inside reactors and other debris were buried during World War II and the Cold War, their disposal was assumed to be permanent.

But current environmental standards call for restoring the areas along the river to their condition before Hanford was used to produce plutonium for the nation's nuclear weapons program. Without cleanup, a person who unknowingly digs up the irradiated fuel pieces 1,000 years from now would be exposed to harmful levels of radiation, Price said.

The fuel pieces being recovered have radiation levels of one to greater than 100 rad per hour, which is approximately 200,000 times the exposure limit set by the Department of Energy, Price said. Because they are so radioactive and the radioactivity is so long-lived, they're required to be disposed of at a national repository at Yucca Mountain, Nev.

Other debris from the reactor burial grounds is being taken to a lined landfill for low-level radioactive waste in central Hanford.

How the fuel pieces ended up in the burial grounds is uncertain. But the 8-inch-long fuel pieces were similar to the dummy spacers used in the reactor, and the work to remove fuel from the reactor core and retrieve it could be difficult, Price said.

It appears the pieces simply got lost, despite procedures for counting fuel before and after it was irradiated.

After fuel was irradiated in tubes within the reactor block, it was pushed out of the rear face of the reactor into large basins of water to cool. Workers then would use long-handled tongs to separate the dummies and the fuel pieces under 20 feet of water needed as a radiation shield.

Because of pressure to produce large quantities of plutonium, power levels of the reactors were increased beyond the design capacity, causing the fuel elements to blister and break, according to DOE's History of the Plutonium Production Facilities at the Hanford Site Historic District, 1943-1990.

In addition, the graphite stack of the reactors expanded, making discharging the fuel from the graphite tube channels sometimes difficult.

When work began to dig up reactor debris burial grounds, there was no documentation or historical knowledge that they would contain irradiated fuel, said Chris Smith, DOE assistant manager for Hanford's river corridor.

The first fuel piece discovered was a surprise, but contractors on the river corridor have adapted to the hazard, he said.

Washington Closure Hanford spends a half day to a full day stirring unearthed material while it is still in burial trenches with an excavator operated by a worker wearing a supplied air respirator. At the end of the day, monitor air filters are checked for radiation.

If workers can confirm there is not airborne contamination, the debris is loaded into a dump truck and taken to a nearby sorting trench to be spread out in a layer six inches to 1 foot thick. Radiological monitors operated remotely are used to scan the debris.

"We approach everything as if it were hazardous and high dose," Miller said.

Workers use long-handled tools to try to identify and remove items with unusual radiation readings. If they are suspected to be irradiated fuel, they are placed in temporary bunkers made of concrete blocks. The corroded pieces are cleaned, measured and weighed to determine their identity.

"Everything buried in the '40s and '50s looks very similar," said Rex Miller, Washington Closure operations manager for field remediation. There are hundreds of similarly shaped pieces 8 to 11 inches long, he said.

Until now, pieces identified as fuel have been packed into reusable shielded shipping casks and driven with security escorts to the K West Basin. However, Tuesday is the last day fuel will be accepted at the K West Basin, where radioactive sludge is being held along with some irradiated scrap fuel.

As Fluor Hanford cleans up the K West Basin, additional found fuel will need to be packaged in single-use storage casks and sent to the central Hanford where it is planned to be stored on concrete pads until it can be shipped off site.

With that project to start up in the fall, Washington Closure has worked to get the fuel found to date delivered to the K West Basin.

The fuel has been moved to the K West Basin in nine shipments, Miller said. To avoid interfering with cleanup at the K Basins, most shipments were made on weekends.

"We think Washington Closure did a good job with the spent fuel shipping campaign," Price said. It's one more reason that the state wants to see full federal funding continue for cleanup work along the river corridor, he said.