Helicopter flights over Hanford this month are expected to provide a detailed map of where radioactive waste and contamination lie in the 37 square miles at the center of the nuclear reservation.
The helicopter is equipped with sensors that can measure levels of radiation and distinguish among types to determine whether it may come from waste containing contaminants such as cesium, plutonium and uranium, said Jon Peschong, a Department of Energy deputy assistant manager for Hanford environmental cleanup.
Without aerial capabilities, the work would have to be done by workers walking the large area or vehicles conducting surveys in areas that are accessible.
“This can cover so much more area,” Peschong said.
The helicopter can take readings for an area 100 feet wide in one pass at about 40 mph. No ground is disturbed, including areas that may have cultural remains from earlier tribal use, and any contamination is not tracked to other areas, he said.
DOE already has done extensive characterization of the center of Hanford, but “this is one more step to make sure we are not missing anything,” Peschong said. The information will be used to develop environmental cleanup plans.
The center of Hanford has burial grounds filled with debris and places where contaminated liquids were spilled or disposed of in the soil. Among the burial grounds are 25 landfills that together received almost 16 million cubic feet of radioactive solid waste.
In 2009 Hanford also used a helicopter for aerial radiological surveys, looking at a 13.7-square- mile area where animals had previously spread contamination after being attracted to radioactive salts left in the soil when liquid waste was discharged. That contamination has since been cleaned up.
The current surveys are done by a helicopter that takes off from the Pasco airport. As it circles over the Columbia River, it takes a reading of the Earth’s natural radiation and sets its instruments to that background level. It also takes a reading on its return flight low over the river two to three times a day.
The project is expected to cost about $950,000, including the Hanford support crew and the report that will be prepared with the findings. The flights should be completed between this weekend and midweek.