Scientists at the Carlsbad Environmental Monitoring and Research Center, an entity of New Mexico State University's College of Engineering, have detected trace amounts of the radioactive isotopes americium and plutonium on an air filter from an ambient air sampling station located approximately six-tenths of a mile northwest of the Waste Isolation Pilot Plant on the WIPP Access Road outside Carlsbad, N.M. It is important to note that levels detected are well below any level of public or environmental concern.
CEMRC personnel installed the filter at the air sampling station at about 12:40 p.m. Tuesday, Feb. 11, prior to the U.S. Department of Energy announcement of the detection of radiation within the WIPP underground facility at about 11:30 p.m. Friday, Feb. 14. CEMRC personnel removed the air sampling station filter for analysis at 9:40 a.m. Sunday, Feb. 16.
CEMRC scientists conducted destructive analysis and radiochemical separation on the filter at the CEMRC laboratory, and measured for alpha and gamma radiation activity. Analyses show that 0.64 Becquerels of americium and 0.046 Becquerels of plutonium were found deposited on the filter media. The Becquerel is an international unit of measure of radioactivity and is defined as one disintegration per second.
The levels detected during this time period are higher than the normal background levels of radioactivity from transuranic elements commonly found at this sampling station, so their presence during this specific timeframe appears to indicate a small release of radioactive particles from the WIPP underground exhaust shaft in the brief moments after the radiation event occurred and before the WIPP ventilation system shifted to filtration mode. Even though trace amounts of radioactive particles have been detected at this sampling station between the early afternoon of Tuesday, Feb. 11, and the morning of Sunday, Feb. 16, it is important to note that all of the radiation levels detected thus far have been very low and are well below any level of public and environmental hazard.
CEMRC has detected plutonium and americium at this sampling site on four separate occasions over the past 15 years with the highest previous activity measured at 0.004Bq for plutonium and 0.0005Bq for americium. The EPA actionable limit for these isotopes is 37.0Bq. Eating a banana would expose an individual to more radiation than these previous detections would.
A second ambient air sampling station located approximately 12 miles southeast of the WIPP facility on Highway 128 showed no detection of radioactive particles. A third ambient air sampling station located about 109 yards northwest of the WIPP exhaust shaft and within the WIPP property protection area has not yet been analyzed because CEMRC personnel were not able to access the area for collection of the filter until about 9 a.m. Tuesday, Feb. 18. Results from this filter will be released once the destructive analysis and radiochemical separation/counting processes have been performed.
CEMRC provides a free lung and whole body counting service to adult citizens living within a 100-mile radius of the WIPP facility. Concerned citizens can be measured to see what radiation may exist in their lungs and whole body. This service is available by scheduling an appointment with the CEMRC Internal Dosimetry Lab at 575-234-5530.
CEMRC, funded through a financial assistance grant by the U.S. Department of Energy Carlsbad Field Office, is tasked with conducting an independent environmental monitoring program of the WIPP facility for the citizens of Carlsbad and southeast New Mexico. CEMRC's environmental monitoring program consists of the evaluation of samples of various media for the presence of radiological and non-radiological components likely to be found in the waste at WIPP. These media include WIPP underground exhaust air; ambient air around the WIPP repository; drinking water samples from the five municipal water systems in the area, as well as the Double Eagle well field; soil samples from the region around the WIPP repository; and surface water and sediment samples from the three public reservoirs in the area, Brantley Lake, Lake Carlsbad and Red Bluff Lake.