nuclear-news

Newly released lab tests of air filters from the Department of Energy’s waste repository in New Mexico documented a significant spike in radiation during an incident last month, although contamination in air that actually reached the environment was well below EPA standards.

The Carlsbad Environmental Monitoring and Research Center measured radionuclides in samples taken following a radiation alarm at the Waste Isolation Pilot Plant on Feb. 14. The cause of the alarm remains under investigation, and testing recently revealed small internal doses among 13 people working there at the time. The alarm caused the ventilation system to immediately direct air through a bank of high efficiency particulate absorption filters. Testing of a filter positioned before the HEPA system and removed several hours after the alarm showed 1,365 becquerels per cubic meter of americium and 672 Bq/m3 of plutonium. By Feb. 21, those levels fell substantially to 0.65 Bq/m3 of americium and 0.06 Bq/m3 of plutonium per day.

The lab also tested filters on the other side of the HEPA system that provide an estimate of the amount of radiation that actually entered the atmosphere. A filter installed on the day of the alarm and removed four days later found levels of americium at 1.81 Bq/m3 and levels of plutonium at 0.224 Bq/m3. (For context, the Environmental Protection Agency’s actionable level of airborne contamination is 37 Bq/m3.) Scientists, who are continuing to sample air from WIPP, reported that contamination levels in the post-HEPA-filter air decreased exponentially over the following days.

From CEMRC: