238Pu and 239+240Pu inventory and distribution through the lower Rhone valley terrestrial environment (Southern France)
Résumé
Because of atmospheric global fallout due to thermonuclear tests performed between 1945 and 1980 and to the American SNAP 9A satellite explosion in 1964, plutonium's long-lived alpha emitter isotopes (238Pu, 239Pu and 240Pu) can be found everywhere in the environment. In the soils of the lower Rhone valley, over a surface area of approximately 11,000 km2, existing results allow estimation of the total inventory resulting from this origin of 551 GBq as regards these radionuclides. The Marcoule Nuclear Reprocessing Plant (NRP) has been releasing 238Pu and 239+240Pu into the environment for over 40 years in the region and is as such a second likely source for Pu input. This article gives a global review of plutonium distribution in this particular region. It is shown that releases from Marcoule, although accounting for less than 2% of the total Pu inputs into the terrestrial environment, are responsible for localised and measurable Pu enrichments close to the facility (+2.8 GBq), and in the Rhone delta where sediments from the river settled during the past floods (+0.1 GBq). Irrigating with water from the Rhone River also allowed the transfer of approximately 3.8 GBq of 238Pu and 239+240Pu to the soils for the whole 1960-1998 period. These inputs, distributed over wide irrigated surface areas, do not induce significant increases of soil Pu-activity levels. In a second section, this study confirms that most of the plutonium existing in the terrestrial environment is accumulated in the soil. Less than 0.1% of the activities exist currently in the plant compartments, and the flows exported by agricultural productions are very low, although we are interested here in a French region where agriculture prevails. © 2005 Elsevier B.V. All rights reserved.
Mots clés
Isotopes
Rivers
Sediments
Soils
Marcoule
Rhone river
Terrestrial environments
Plutonium
plutonium 238
plutonium 239
plutonium 240
plutonium
fallout
nuclear weapons testing
plutonium isotope
pollution
radioactive waste
agriculture
article
environmental monitoring
flooding
irrigation (agriculture)
plant
pollution monitoring
pollution transport
priority journal
radioactivity
river
sediment
soil
soil pollution
water pollution
air pollutant
crop
France
radiation accident
soil pollutant
telecommunication
Eastern Hemisphere
Eurasia
Europe
Western Europe
World
Accidents
Radiation
Air Pollutants
Radioactive
Crops
Agricultural
Environmental Monitoring
Radioactive Fallout
Satellite Communications
Soil Pollutants