Measurement of low-level radioactivity in environmental samples by gamma-ray spectrometry
A low-level, high-purity Ge detection system was set up at about 15 m above the sea level in a normal counting room where the exposure rate was about 60 nSv/h. A background reduction was achieved by material selection, cryostat configuration and a single lead shielding. The integrated count rate within the energy interval 70-3000 keV was (0.498 +/- 0.001)/s. The background in this energy range was reduced by a factor of about 100. An efficiency calibration of the detector in the energy range 50-2000 keV and according to the Marinelli beaker configuration type IEC-450, filled up with different matrices and suitable radionuclides, was performed. Field sampling of Phragmites communis and Juncus communis and gamma-ray measurements, performed on dry matrices after treatment of the fresh material, indicated low-level contents of the nuclides 134Cs, 137Cs, 60Co, 232Th, 226Ra, 7Be and 40K distributed in the plants. It is concluded that both selected plants are suitable bioindicators for measuring the distribution of certain anthropogenic and natural radionuclides in the environment.
Bibliographic Reference: Paper presented: ICRM Symposium on Low-Level Measuring Techniques and Alpha Particle Spectrometry, Monaco (MC), June 4-7, 1991
Availability: Available from (1) as Paper EN 36208 ORA
Record Number: 199110838 / Last updated on: 1994-12-02
Original language: en
Available languages: en