This note describes a radiochemical procedure for the determination of technetium-99, a pure beta emitter (0.29 MeV maximum energy) with a half-life of 2.12 X 105 years, at levels as low as 0.5 dpm per liter of water. Most separation procedures in the literature are designed to separate much larger quantities of technetium, usually from fission products. Typical of these are the procedures collected by Anders (1). Where macroquantities are available, as in the determination of technetium for the measurement of nuclear fuel burnup (2, 2), chemical-instrumental methods are employed. These methods cannot be used at the low technetium concentrations found in the environment. Separation procedures that are designed for low concentrations are those for urine (4) and rain ( 5), but the former method does not provide adequate separation from some interfering activities and does not have adequate sensitivity, while in the latter method the technetium recovery is low and uncertain. Parallel studies that might be modified for analytical work are the search for long-lived technetium in minerals ( 6), the determination of technetium from the spontaneous fission of uranium-238 in pitchblende ores (7, 8), and the search for technetium produced in molybdenum ores by cosmic-ray neutrons (9).There is no published procedure for the determination of technetium-99 that is applicable to the analysis of large numbers of environmental water samples. With the increasing availability and use of gram to kilogram quantities of this fission product, such a procedure is needed. The present work provides a method for the determination of small amounts of technetium-99 in aqueous solutions, especially in naturallyoccurring water. EXPERIMENTALReagents. Tri-isooctylamine (TIOA), Bram Metallurgical Chemical Co., Philadelphia, Pa., reagent grade CP, was used without further purification to form 5% (V/V) solutions with xylene. The ruthenium carrier was prepared by dissolving 10 grams of C. P. ruthenium trichloride, A. D. MacKay, Inc., New York, N.Y., in 6TV HC1 and diluting to 500 ml with 6TV HC1. The ruthenium concentration was about 10 mg/ml.Tracers. Technetium-99 was obtained from Oak Ridge National Laboratory as an aqueous solution of ammonium pertechnetate. The concentration was determined by four-pi (1) E.
The results of the environmental monitoring program conducted at Site A/Plot M in the Palos Park Forest Preserve area for CY 1986 are presented. The monitoring program is the ongoing remedial action that resulted from the original radiological characterization of the site. The program consists of sample collection and analysis of air, surface and subsurface water, and bottom sediment to determine the migration pathway of water from the burial ground (Plot M) to hand-operated picnic wells, establish if buried radionuclides other than hydrogen-3 have migrated, and generally characterize the radiological environment of the area. The program was expanded late this year to study the migration of non-radiological hazardous waste constituents that may have been buried with the radioactive waste. This was done by analyzing borehole water samples for selected heavy metals and organic compounds. Earlier studies had determined that hydrogen-3 (as tritiated water) migrated from the burial ground and was present in minute concentrations in two nearby hand-pumped picnic wells. Hydrogen-3 in the Red Gate Woods picnic well continued to show the same pattern of elevated levels in the winter and low concentrations in the summer, out the magnitude of the winter peak was significantly less than in earlier years. Tritiated water continues to be detected in a number of wells, boreholes, and surface streams. For many years it was the only radionuclide found to have migrated. Recent measurements indicate the presence of strontium-90 in borehole water next to Plot M. However, the results of the program established that the radioactivity remaining at Site A/Plot M does not endanger the health or safety of the public visiting the site or those living in the vicinity. 1.0 Introduction This report presents and discusses the monitoring data obtained during calendar year 1986. The program is the ongoing remedial action that resulted from the radiological characterization of the former site of Argonne National Laboratory and its predecessor, the University of Chicago's Metallurgies.! Laboratory, which was part of the World War II Manhattan Engineer District Project, in the Palos Park Forest Preserve southwest of Chicago, IL. The Laboratory used two locations in the Forest Preserve: Site A, a 19-acre area that contained experimental laboratory and nuclear reactor facilities; and Plot M, a 150 ft x 140 ft area used for the burial of radioactive waste. These locations are shown in Figures 1.1 and 1.2. To assist in understanding this report, reference should be made to the previous comprehensive reports on this subject, ' which provide greater detail and illustrations on sampling locations and descriptive material and give the results through 1981, and to the annual reports for 1982, 1983, 1984, and 1985. ' Earlier data will not be repeated in this progress report, but reference will be made to some of the results. Operations at Site A began in 1943 and ceased in 1954. Among the research programs carried out at Site A were reactor physics studies, ...
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