Measurement of effective radium in rocks and soils | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

Twitter

Aller au compte twitter

Research Departments

Physics of natural sites

  Measurement of effective radium in rocks and soils

Measurement of effective radium-226 concentration in solid materials

Several methods have been practised since 2007 to measure the radon emanation potential of solid materials. This emanation power is now referred to as effective radium-226 concentration, ECRa, product of radium-226 activity concentration CRa and of the emanation coefficient E, probability that a radium-226 atom emits a radon-222 atom in the pore space. Effective radium concentration is expressed in Bq/kg.

 

Instruments

Scintillating flasks and CALENTM photomultiplier counters. DOSIRAD or ALGADE films. AlphaGUARDTM, BarasolsTM, and CANARYTM recorders.

 

Experimental protocols

The measurement of ECRa is based on accumulation experiments: the material to be measured is enclosed in an airtight container and the increase of radon-222 concentration in the air volume of the container is measured as a function of time. For this purpose, continuous measurements using recorders such as AlphaguardTM, BarasolsTM and CANARYTM, or intermittent measurements using scintillating flasks are done. Alternatively, integrating devices such as films can be used. All these various methods are practiced in our laboratory. To treat large quantities of samples, one method, referred to as our standard method, has been developed using scintillating flasks. Based on more than 13,000 accumulation experiments, several thousands of samples have been measured before April 2017: more than 1500 rocks, more than 1300 topsoils, and more than 500 sediments. After 2015, two high-sensitivity methods (LAF and SLC) were developed, which cannot measure that many samples, but which allow measuring samples of a few grams and sometimes as small as one gram (biological samples, meteorites, single crystals, etc...).

 

Experimental uncertainties

Typical uncertainties for the various methods (Flasks, Films, Accumulation in flask) and high-sensitivity methods (LAF, SLC) are given in the following graph.

Applications

Examples of applications have been demonstrated in various fields: geological mapping, sedimentology, characterisation of hydrothermal systems, environmental problems (polluted sites) or transfer of radionuclides to the biosphere (see documents referenced below). Several other novel investigations are under way.

 

Contact

Measurements can be carried out on demand. With the standard method, large quantities of samples can be handled without difficulty routinely (100 samples, 100 g per sample). When quantities are small (1 to 10 grams), it is necessary to use the high-sensitivity methods which require more care and efforts. To get a price offer, please get in touch with one team member (perrier@ipgp.fr or girault@ipgp.fr), stating the goals and conditions.

 

Manufacturer of the instruments

www.algade.fr

www.dosirad.fr

 

Documents

General introduction on the measurement of radium-226 concentration (standard method):

Perrier, F., F. Girault, H. Bouquerel, Effective radium-226 concentration in rocks, soils, plants, and bones, In Gillmore, G.K., Perrier, F.E., Crockett, R.G.M. (eds) Radon, Health and Natural Hazards. Geological Society, London, Special Publications, 451, SPA451.8, 2016.

Girault, F., F. Perrier, Measuring effective radium concentration with large numbers of samples Part II – General properties and representativity, Journal of Environmental Radioactivity, 113, 189-202, 2012.

Girault, F., F. Perrier, Measuring effective radium concentration with large numbers of samples Part I – Experimental method and uncertainties, Journal of Environmental Radioactivity, 113, 177-188, 2012.

Perrier, F., F. Girault, Measuring effective radium concentration with less than 5 g of rock or soil, Journal of Environmental Radioactivity, 113, 45-56, 2012.

Girault, F., F. Perrier, Heterogeneous temperature sensitivity of effective radium concentration from various rock and soil samples, Natural Hazards and Earth System Sciences, 11, 1619-1626, 2011.

Relationship to magnetic susceptibility and application to polluted sites:

Girault, F., F. Perrier, C. Poitou, A. Isambert, H. Théveniaut, V. Laperche, B. Clozel-Leloup, F. Douay, Effective radium concentration in topsoils contaminated by lead and zinc smelters, Science of the Total Environment, 566-567, 865-876, 2016.

Girault, F., C. Poitou, F. Perrier, B.P. Koirala, M. Bhattarai, Soil characterization using patterns of magnetic susceptibility versus effective radium concentration, Natural Hazards and Earth System Sciences, 11, 2285-2293, 2011.

Application to the characterisation of soils and sediments:

Perrier, F., F. Girault, H. Bouquerel, L. Bollinger, Effective radium concentration in agricultural versus forest topsoils, Journal of Environmental Radioactivity, 160, 123-134, 2016.

Girault, F., A.P. Gajurel, F. Perrier, B.N. Upreti, P. Richon, Radon emanation of heterogeneous basin deposits in Kathmandu Valley, Nepal, Journal of Asian Earth Sciences, 40, 595-610, 2011.

 

Geophysical and geological applications in the Himalayas:

Girault, F., F. Perrier, The Syabru-Bensi hydrothermal system in central Nepal: 2. Modeling and significance of the radon signature, Journal of Geophysical Research Solid Earth, 119, 4056-4089, 2014.

Girault, F., F. Perrier, R. Crockett, M. Bhattarai, B.P. Koirala, C. France-Lanord, P. Agrinier, M. Ader, F. Fluteau, C. Gréau, M. Moreira, The Syabru-Bensi hydrothermal system in central Nepal: 1. Characterization of carbon dioxide and radon fluxes, Journal of Geophysical Research Solid Earth, 119, 4017-4055, 2014.

Girault, F., F. Perrier, A.P. Gajurel, B.P. Koirala, M. Bhattarai, L. Bollinger, M. Fort, C. France-Lanord, Effective radium concentration across the Main Central Thrust in the Nepal Himalayas, Geochimica et Cosmochimica Acta, 98, 203-227, 2012.

High-sensitivity methods and application to extra-terrestrial samples:

Girault, F., F. Perrier, M. Moreira, B. Zanda, P. Rochette, Y. Teitler, Effective radium-226 concentration in meteorites, Geochimica et Cosmochimica Acta, 208, 198-219, 2017.