Three more Hanford workers reported suspicious odors outside a Hanford tank farm Thursday afternoon.
They bring to 12 the number of workers so far this month who have reported odors outside tank farms that could be from chemical vapors associated with underground tank waste.
The three workers in the Thursday incident all declined medical evaluations, as did the nine workers who detected an odor on Wednesday.
Supplied air respirators are required inside the fence lines of Hanford tank farms where waste is stored underground, but both incidents this week were outside any tank farms.
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Thursday workers were performing calibrations on a continuous air monitoring system used for the AZ Tank Farm, but located outside it.
They opened the sample system cabinet and reported smell variously reported as burning electrical, musty and an ammonia odor.
On Wednesday workers were near work trailers about 200 yards outside the AP Farm fence line for pre-job briefings.
In both incidents, workers were told to leave the area and access was restricted until analyses of air samples showed air was safe to breathe.