ABSTRACT
Within the framework of the European Metrological Research Program (EMRP) IND04 MetroMetal 'Ionizing radiation metrology for the metallurgical industry', joint research carried out by 14 metrological institutions from countries within the European Union and the company ENVINET, questions concerning the determination of radioactivity in samples relevant to the metallurgical industry were resolved. The results of project tasks, namely questionnaire, composite standards development and samples from metallurgical industry measurement, are presented here.
Subject(s)
Biomedical Research , Metallurgy , Occupational Exposure/analysis , Radiation Monitoring/instrumentation , Radiation Monitoring/standards , Research Design , European Union , Humans , Industry , Radiation Protection , Surveys and QuestionnairesABSTRACT
The determination of gaseous forms of radionuclides in ventilation stacks utilising grab samples was performed as a part of independent monitoring of nuclear power plants in the Czech Republic. The activities of radionuclides (e.g. (41)Ar, (133)Xe, (135)Xe, (85m)Kr, (87)Kr, and (131m)Xe) were determined by semiconductor gamma-ray spectrometry in samples collected into pressure vessels. Radiochemical preparation of samples for determination of (14)CO(2), combustible (14)C forms, and (85)Kr was performed after the radioactive decay of radionuclides with short half-life.
Subject(s)
Air Pollutants, Radioactive/analysis , Nuclear Power Plants , Radioisotopes/analysis , Argon/analysis , Carbon Dioxide , Carbon Radioisotopes/analysis , Czech Republic , Gases/analysis , Krypton/analysis , Spectrometry, Gamma , Xenon Radioisotopes/analysisABSTRACT
Forty-four soil samples were taken around the nuclear research centre Rez, near Prague. The mean activity concentrations of 238Pu, 239,240Pu, 241Am, 90Sr and 137Cs in uncultivated soil were 0.010, 0.26, 0.12, 2.7 and 23 Bq.kg(-1), respectively. Contents of radionuclides in cultivated soil were lower and in forest soil higher than in uncultivated soil. The mean activity ratios of 238Pu/239,240Pu, 241Am/239,240Pu, 90Sr/239,240Pu and 239,240Pu/137Cs in uncultivated soil were 0.041, 0.47, 10.9 and 0.013, respectively. The mean activity ratios in cultivated and forest soils were close to the values given above. It follows from the results that the source of 239,240Pu, 90Sr and 137Cs in the studied area is deposition from atmospheric nuclear tests, in the case of 137Cs also deposition from Chernobyl accident. The contribution of the research centre effluents was not proved for these radionuclides. Increased activity ratio of 241Am/239,240Pu indicates the presence of 241Am in the soils studied emanating from sources other than nuclear tests. Uniform distribution of the 241Am/239,240Pu activity ratio around the nuclear research centre and the absence of an area with evidently higher activity ratio, including at sites lying in the main wind direction, suggest that the additional activity of 241Am does not originate from the nuclear research centre. The additional source might be the deposition following the Chernobyl accident.
