Disposal has been halted as a precaution at Hanford's landfill for low-level radioactive and chemical waste until more is known about a load disposed there Tuesday afternoon.
Workers reported an unpleasant sulfurlike smell and seeing possibly dust or smoke rising from waste being disposed of in the Environmental Restoration Disposal Facility, said Todd Nelson, spokesman for Washington Closure Hanford.
The load had come from cleanup work in a part of B Reactor that's not accessible to the public.
The Department of Energy asked that some housekeeping work be done in the historic reactor to get it in top shape as limited tours are offered and the National Park Service considers possible plans for a Manhattan Project National Historical Park.
When B Reactor was operating, a drum of chemical cleaning compound used in reactor operations was stored in the basement, said Colleen French, B Reactor project manager.
The compound had an unpleasant odor and some of it had spilled onto the basement floor. Recently the basement concrete and soil that still had some of the cleaning compound contamination was removed.
The load of debris taken to the landfill contained no radioactive material. But because B Reactor records are not complete, Hanford officials are investigating the chemical compound to determine why landfill workers saw what may have been a chemical reaction.
About 30 workers at the landfill were evaluated by AdvanceMed Hanford, the site's occupational medicine contractor. However, Nelson said he had not heard that any of the workers had any symptoms.
Construction of an expansion of the landfill and disposal of waste has been halted until Washington Closure knows more. Washington Closure, which operates the landfill, has been adding about 300 truckloads of waste a day to it.
Washington Closure will work through the weekend to make sure the landfill can resume operations safely as soon as possible, Nelson said.