Reload Index (ZRiChK UMCS)

 

 

STUDIES OF MIGRATION MECHANISM OF RADIOACTIVE ISOTOPES IN NATURAL ENVIRONMENT,

STUDY ON VERTICAL MIGRATION OF PLUTONIUM IN SOIL PROFILES OF THE WIEPRZ RIVER VALLEY

 

STANISŁAW CHIBOWSKI, ANDRZEJ KOMOSA,

JOLANTA ORZEŁ

DEPARTMENT OF RADIOCHEMISTRY AND COLLOID CHEMISTRY

 

 

The Wieprz river with its drainage basin of more than ten thousand square kilometers occupies central part of Lublin region. Uplands cover nearly 60% of this area; the rest are lowland plain. Geologically all this terrain is formed of chalk type bedrock with quaternary sediments as loess and sand on the surface. Lowlands are characterized with relatively shallow level of ground water and easier penetration of rainwater into the rock base. The change of composition and properties of soil down the river influences the radionuclide transport from soils to river sediment and downwards the soil profile as well.

Plutonium present in soil is the result of nuclear weapon testing and, in small extent, of Chernobyl accident. Introduced to upper atmospheric layer plutonium fell down the Earth surface. Observation of its migration in the environment can give an information about a transport of other trace elements.

Down the whole Wieprz River four points were selected, where the soil profile was exposed (near the riverbank) down to 40 cm (with 5-cm layers). Collected soil samples were air-dried, ground, sieved and subjected to determination of alpha emitting plutonium isotopes. The proper radiochemical procedure of separation of these nuclides was applied. The procedure consists of leaching with hydrochloric acid, coprecipitation with ferric hydroxide, next with calcium oxalate, anion exchange separation, electroplating of isolated nuclides and alpha spectrometric measurement [1].

Basing on the results of measurement of plutonium concentration in particular layer a vertical migration rate of plutonium was calculated. A compartment model was applied and the global fallout as the main plutonium source was assumed [2]. Calculated average vertical migration rate of plutonium ranges from 0.5 to 1.1 cm/year and reveals large variability between particular layer.

 

References:

[1] A. Komosa, Polish J. Environm. Studies 8 (199) 155.

[2] J. Zygmunt, Thesis, Lublin 2000.

 

Grant KBN 3T09C 03415