Writer: Emily C. Kelley
New Mexico State University’s College of Engineering has a unit in Carlsbad whose mission is to conduct an independent program to monitor people and the environment for exposure to radioactive materials.
The facility, called the Carlsbad Environmental Monitoring and Research Center, also studies the Waste Isolation Pilot Plant, commonly known as the WIPP site or WIPP facility, which is a low-level nuclear repository operated by the Department of Energy.
“We make sure the waste that gets put in the WIPP site does not get released back out into the environment,” said Russell Hardy, director of CEMRC.
CEMRC has been in operation in Carlsbad since 1991 and is funded primarily by a Department of Energy financial assistance grant.
“Our original grant began in 1991 and ended Sept. 30 this year,” Hardy said. “It was in effect for about 22 years.”
CEMRC was again awarded the $15 million grant at the rate of $3 million per year for five years, in September. The grant funds the center’s many activities, including air, drinking water and soil monitoring, along with whole body count monitoring for people who live within a 100-mile radius of the WIPP facility, for exposure to radioactive materials.
A CEMRC, the Lie Down and Be Counted program provides counting of the lungs and whole body. This internal dosimetry process uses sensitive counters to measure the tiny amounts of radioactive material typically found inside the human body, but can also provide an assessment of potential exposure to radioactive contaminants of concern.
Participants in the program typically spend about one hour at CEMRC for the scan.
Internal dosimetry staff members, like Ila Pillalamarri, a CEMRC research scientist, monitor the participant in the internal dosimetry room through a video feed. At the conclusion of the scan, Pillalamarri or other staff members from the program interpret the results of the scan, known as a bioassay, for the participant. Results can also be shared with healthcare professionals, if needed.
“We explain to the volunteers what the results mean,” Pillalamarri said.
When Lie Down and Be Counted first started in the late 1990s, internal dosimetry staff completed 300-400 public participant scans per year, but now they average about 30-40 per year.
“Since the WIPP site has been in operation for about 14 years without any incidents, we’ve seen a decline in the number of citizens who participate in our Lie Down and Be Counted Program,” Hardy said. “It’s good that this safety factor is there and that people are trusting of the WIPP site, but it’s also good that we have this capability here in the event that something happened.”
Much of the daily activity at CEMRC revolves around collecting and analyzing samples from the environmental filters in the area. The CEMRC environmental monitoring program examines the air both inside and outside the WIPP repository, along with drinking water and soil in the area, to include surface water samples taken from the bottom of the three lakes in the area, Red Bluff Lake, Lake Carlsbad and Brantley Lake.
“Each day, we collect an air filter – a very thin paper filter, from the WIPP facility. We digest those filters in an acid solution into a weekly composite,” Hardy said. “Just about every day, we’re in the lab preparing those samples. Twice a month, we collect larger paper filters, from the air outside the repository from four sampling sites. When we get drinking water or soil or sediment samples, those take time to prepare and then to analyze, too.”
Once samples are prepared, CEMRC scientists run them through various radiological and non-radiological tests.
“From a radiological point of view, we take that solution and we separate out the various actinides. Primarily, we’re looking for three radioactive actinides – plutonium, americium and cesium. Those are all by-products of the nuclear fission process,” Hardy said. “Most of the waste stored in the WIPP facility was generated from the production and testing of nuclear weapons. If a sample is going to have a radiological component, it’s going to be one of those three types.
“We separate those solutions into the various actinides and then measure the level of radiological activity. On the non-radiological side, we analyze those samples for 37 different elements of heavy metals or salts that are likely to be included in the waste at the waste repository.”
On March 11, 2011, a tsunami hit the Fukushima Daiichi power plant in Japan, causing the plant to lose the ability to cool its reactors, resulting in a meltdown. On March 14, CEMRC observed activity from this event in their environmental filters.
“It took roughly three days (for radioactive material) to come 10,000 miles,” Hardy said. “It was low-level activity, below any environmental concern, but we started seeing iodine-131, tellurium and cesium. We know that it came from Fukushima because of when it happened and because each of the nuclear incidents – whether it’s Chernobyl, Fukushima or Three Mile Island – they each use different mixtures in their fuel rods and they have different types of reactors. When they have an incident, they create their own signature. Looking at these ratios of plutonium, americium and cesium, you can determine which event it was tied to.”
“The four times that we’ve seen plutonium out in the desert (from a 1960 Atomic Energy Commission underground explosion 12 miles from Carlsbad), as well as the Fukushima incident, just validates that what we’re doing works,” Hardy said. “Most of the time we see zero, and that’s a good thing, but if there ever were a release, we would be able see it and with the data that we have, be able to determine where it came from.”