GTRI

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: 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.

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.

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.

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).