On April 8, 1993, at the Los Alamos Health Research Laboratory (HRL), Radiological Control Technicians detected alpha contamination of 1800 dpm/100 cm2 in a ventilation duct. A room was being radiologically characterized prior to remodeling and had been unused and unoccupied for the past ten years. Analysts verified that the contamination was PU-239, PU-241, and Americium 241. The facility currently has no plutonium operations. Investigators believe the source of the contamination dates to before 1984 (ORPS Report ALO-LA-LANL-HRL-1993-0003).
The area was flagged with yellow tape and posted. Personnel installed air filters and investigators are continuing to search for the source of the contamination. Extensive examination of the ducts is underway to determine the extent of the contaminated area. HRL staff will develop remediation action after the extent of the contamination is known.
DOE facilities have had varied missions and life spans. When a new mission is contemplated for an older facility, special care needs to be taken to ensure that potential radiological contamination from defunct operations are accounted for prior to commencing new work.