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About Us: Research Facilities: Environmental Radiation Center (ERC)

Environmental Radiation Center (ERC)

The GTRI Environmental Radiation Center performs research, service, and student training in radiological monitoring of the environment. Recent products of research in radiological environmental monitoring, analytical radiochemistry, and radiation protection are shown in the tabulation of thesis titles and research publications. Interaction with students and faculty is considered vital in view of the laboratory's location in the Georgia Tech Research Institute. An important example is the cooperative effort with the School of Chemistry to develop student training in radiochemistry.

As a service, the laboratory performs analyses for very low levels of environmental radioactivity to assist the Georgia Environmental Protection Division in its responsibility to monitor public drinking water supplies and the environment at commercial and Federal nuclear facilities. Such analyses are also performed for industry and other government agencies. These ongoing projects provide trained professionals and state-of-the-art radiation detection instruments that support the research and training.

Laboratory facilities and professional skills are also devoted to homeland security and emergency response activities. The laboratory supports the state agency in emergency preparedness, notably for nuclear facility incidents. It has tested its radiation detectors with FDA intercomparison samples. It works with NNSA/DOE to support radioanalytical chemistry training by preparing a textbook and laboratory manual and advising on incident attribution.

The ERC has operated since 1977. Its facilities consist of the radioanalytical laboratory and radionuclide counting facility described below.

Radiochemistry:

Dissolving Soil Samples for Strontium and Plutonium Testing

The function of the ERC radiochemistry laboratory is to prepare samples and perform chemical separations for radionuclides that cannot otherwise be tested by gamma-ray isotopic methods. Preparation of solid samples by the radiochemistry group requires more effort than for water samples. Ashing furnaces and microwave oven dissolution are used to convert solid samples into a wet-chemistry matrix prior to chemical separation.

Radiochemistry Preparation of Samples for Uranium Testing

Samples in a wet-chemistry matrix are processed like water samples by radiochemists. After chemical separation, mounting of the sample for radio-analytical counting is the last step conducted by the radiochemist. For alpha-particle spectrometry, this involves electroplating. Routine testing is conducted for the following radionuclides and for gross-screening: Gross alpha, gross beta, gamma-isotopic, x-ray isotopic, tritium (H-3), Sr-89, Sr-90, radioiodine (I-131), Ra-226, Ra-228, gross uranium, isotopic uranium (U-234, U-235, U-238), isotopic plutonium (Pu-238, Pu-239/240), and Am-241.

Biological Sample Preparation:

Fish samples undergo several processes, including dissection, homogenization, packing for gamma-ray spectrometer testing, weighing, moisture extraction for H-3, % moisture determination, drying, ashing (for alpha/beta), radiochemistry (for Sr, U, and Pu), and electroplating for U and Pu testing. Similar processes are applied for testing other biota and vegetation.

Electroplating Samples for Actinide Analysis

Drinking Water:

The Laboratory processes over 1000 samples per year for Safe Drinking Water compliance testing. The majority of these samples are tested for naturally occurring radionuclides found in ground water. Ra-226 and Ra-228 are the primary radionuclides tested. Radiochemical separations are required.

Operating Liquid Scintillation Counter in Counting Facility

Radioanalytical Counting Facility:

The function of the ERC radioanalytical counting facility is to count, identify, and quantify the radionuclides in the prepared samples, based on the radioactive emissions observed in the samples. A wide variety of radioanalytical detection and analysis equipment must be used. A summary of the instruments utilized follows:

Major Radioanalytical Instrumentation & Usage
QuantityDescriptionUtilization
5HpGe Gamma Detector SystemsGamma Isotopic
1X-Ray Detector SystemX-Ray Isotopic (I-129, etc.)
16PIP Alpha Detector SystemsAlpha Isotopic (Pu, U, etc.)
3Liquid Scintillation Detector SystemsH-3, C-14, etc.
4Low-Level Alpha / Beta Systems Alpha, Beta, Sr-89/90, Ra-228, Uranium, etc.
1Beta-Gamma Coincidence SystemLow-Level I-131
1Automatic TLD SystemTLD Dosimetry
6Lucas Cell CountersRa-226 analysis
1Portable MCA & HpGe Field Gamma Isotopic

Quality Assurance:

Quality assurance is an integral part of Laboratory operations. A valid, on-going quality assurance program is necessary to maintain data credibility. The quality assurance program consists of the following elements: (1) personnel skill qualifications, (2) training programs, (3) procedural development, (4) utilization of approved standard methods, (5) participation in cross-check and blind sample programs, and (6) programs for regular maintenance and calibration of analytical equipment.

The Laboratory determines counting efficiencies for its radiation detectors with radioactivity standards prepared by or traceable to the National Institute of Science and Technology. It then participates in the Environmental Resource Associates crosscheck programs required by the U.S. EPA, and the U.S. DOE (MAPEP). The following intercomparison samples are processed routinely:

Quality Assurance Crosschecks
TYPE OF RADIOACTIVE SAMPLE
IN CROSS-CHECK PROGRAM
SAMPLE MEDIACROSS-CHECK
FREQUENCY
Alpha/BetaWaterAnnually
UraniumWaterAnnually
Ra-226 & Ra-228WaterAnnually
H-3WaterAnnually
Gamma EmittersWaterAnnually
Sr-89 & Sr-90WaterAnnually
low-level I-131WaterAnnually
Blind SamplesWaterAnnually
Alpha, Beta, Cs-137, Sr-90Air FilterAnnually
Alpha/Beta/Sr/Pu/Gamma (DOE)Water/Veg/AirEvery 6 Months
Alpha/Beta/Sr/Pu/Gamma (DOE)Sed/SoilEvery 6 Months
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