HANFORD -- New technology developed by Washington Closure Hanford is detecting irradiated fuel lost in Hanford's burial grounds before it leaves the excavator bucket.

It can detect gamma radiation from cesium 137 in irradiated fuel and distinguish it from the cobalt 60 found in most of the other irradiated and rusting metal discarded in the burial grounds, including those with high radiation.

"There's definitely a lot of fuel out there and we want every piece of it found," said John Price, environmental restoration project manager for the state Department of Ecology, a Hanford regulator.

Hanford workers have found 74 pieces or fragments of highly radioactive fuel as they excavate World War II and Cold War burial grounds not far from the Columbia River. The fuel was irradiated in Hanford's reactors to produce plutonium for the nation's nuclear weapons program.

The first fuel found in 2004 was a surprise to workers, in part because the plutonium the fuel pieces contained was so valuable. Some likely was mistakenly discarded and others may have been discarded because pieces had been broken.

Most of what's dug up at the burial grounds can be disposed of at the Environmental Restoration Disposal Facility, a landfill for low-level radioactive waste in central Hanford. But irradiated fuel must be shipped to a national deep geological repository, such as Yucca Mountain, Nev., for permanent disposal.

The new technology developed by Washington Closure called Compton Ratio Analysis for Testing Environmental Radioactivity, or CRATER, is the third method that's been tried to find the fuel pieces among other debris in the burial grounds, including thousands of same-sized spacers.

When burial ground work started, workers watched as excavators dumped waste and then searched the piled debris with radiation detectors on long-handled tools. Next they tried hauling debris to shallow trenches and spreading it out to search.

"This is a leap forward," said Ed Traverso, who led development of CRATER for Washington Closure. It increases efficiency by reducing handling of the waste and reduces possible worker radiation exposure.

As waste was lifted out of a burial ground near D Reactor on Tuesday, the excavator operator paused with the bucket raised halfway to allow CRATER to run for 15 seconds to check for irradiated fuel. When it detected no radiation from cesium, CRATER sent a message to radiation control technicians waiting nearby saying "no fuel fragment identified."

It uses off-the-shelf components hardened to survive movement of the excavator arm and cold and hot temperatures and uses Bluetooth technology to transmit information.

In its first month after testing, CRATER has been used at the burial grounds near D Reactor. But the Department of Energy is looking forward to its use at other burial sites.

"We always want our contractors to be safe and efficient and this does both," said Cameron Hardy, DOE spokesman.