Radioactive concrete sources for calibration of uranium exploration and environmental field instruments constructed at IRD/CNEN, Brazil
- 1. Instituto de Radioprotecao e Dosimetria, Rio de Janeiro (Brazil)
- 2. Risoe National Lab., Roskilde (Denmark)
Description
A radiometric calibration system constructed at the Instituto de Radioprotecao e Dosimetria (IRD) of the Brazilian Nuclear Energy Commission (CNEN) to be used by geophysicists interested in uranium exploration and scientists working with natural radioactivity and environment is described. The system consists of 8 radioactive concrete sources. The sources are of cylindrical shape with 3m diameter and 0,5m thickness weighting approximately 7.5 tonnes. Uranium, thorium and potassium ores were added to the concrete under conditions to achieve perfect homogenization. One hundred four samples were collected and analysed by eight laboratories. In addition, in-situ radiometric grade determination were performed with calibrated instruments. U, Th and K reference values were then assigned to each source. The system also has a 4m diameter water pond for cosmic-ray and instrument noise corrections. (Author)
Availability note (English)
MF available from INIS under the Report Number.Abstract (Portuguese)
Descreve-se um sistema de calibracao radiometrico, construido no IRD/CNEN para ser usado por geofisicos interessados na exploracao do uranio e pesquisadores que trabalham com radioatividade natural e meio ambiente. O sistema consiste em 8 fontes de concreto radioativo. Essas fontes sao de forma cilindrica com 3m de diametro e 0.5m de espessura pesando aproximadamente 7.5 toneladas. O concreto foi adicionado com minerios de uranio, torio e potassio homogeneamente. Foram analisadas 104 amostras por 8 laboratorios. Determinou-se o grau radiometrico in-situ com instrumentos calibrados. Os valores referencia do U,Th e K foram entao atribuidos a cada fonte. O sistema possui tambem um tanque de agua de 4m de diametro para correcoes de ruidos de raios-cosmicos e instrumentos. (M.C.K.)Files
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Additional details
Publishing Information
- Imprint Pagination
- 74 p.
- Report number
- INIS-BR--556
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 17089883
- Subject category
- S46: INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY;
- Descriptors DEI
- BRAZILIAN CNEN; CALIBRATION STANDARDS; CONCRETES; LAKES; POTASSIUM; RADIATION DETECTORS; RADIATION SOURCES; SAMPLING; SPECIFICATIONS; THORIUM; URANIUM
- Descriptors DEC
- ACTINIDES; ALKALI METALS; BRAZILIAN ORGANIZATIONS; BUILDING MATERIALS; ELEMENTS; MATERIALS; MEASURING INSTRUMENTS; METALS; NATIONAL ORGANIZATIONS; SURFACE WATERS