The Fifth Conference64 Nuclear Science and Its Application”, 14-17 October 2008
EPR OF SEMIPALATINSK TEST SITE REGION SOILS AND MINERALS
S. PIYOYAROV. T. SEREDAVMA, A. RUKHIN, V. GABDRAKİPOV
Institute of Nuclear physics of the National Nuclear Center of Republic Kazakhstan
Radiation effects consequences on environment and population o f the regions where the nuclear weapon tests were provided or any radiation accidents took place are caused by influence of all radiating factors but mostly local long living radionuclide pollutions. Former Semipalatinsk
nuclear test site (STS) and storage of radioactive wastes o f the uranium mining enterprise for ex at
Actau -Koshkar-Ata in Kazakhstan, Basin ofTecha River in Russia, Chernobyl in Ukraine as well other unfavorable from ecological point of view places have similar problems.
Complex radiation influence could lead to accumulation in environmental objects of considerable concenfrations of radiating defects of free radical (PR) type. This ecological aspect, as contrary to radionuclide pollutions, remains, however, practically ^investigated, despite of it is quite actual, particularly for the Semipalatinsk test site in Kazakhstan.
For revealing of possible radiating influence of explosions there was provided study o f more representative and practically important objects — soils and minerals from the STS region.
EPR signals of complicated shape of line at g-factor~2,00 were observed in spectra o f studied
soils and minerals, which consist mainly o f alumosilicates, silicates and oxides. Difference o f relaxation parameters found out for paramagnetic centers o f various type had caused superposition o f the signals from corresponding spin -system s, which have been separated using variety o f
registration parameters. There was registered EPR-signal from E’j-centers, which are known for
S i0 2*nH20 and quartz minerals, together with accompanied signal — presumably, from peroxide
radicals, both signals can have been created by technogenic irradiation.
Probably, radiogenic signals found in STS soils could be used for retrospective EPR-
dosimetry o f polygon as they are stable at the conditions o f mineral nature substances existing at STS and their radiating origin was proved by means o f additional artificial irradiation. EPR signals were recorded in various mineral and size fractions o f soils, that indicates on different “sensors” o f irradiation, the analogous centers one can observe in minerals which are spread over the STS
region.
The quantum-chemical model was suggested for describing o f radiation-induced centers o f FR type accumulation taking into account combination o f the processes o f formation and decay o f
defects on the possible mechanisms.
The problem o f ecologie situation study at the regions o f nuclear tests and accidents in such
aspect is quite important and actual not only for Semipalatinsk region.
Section III Radiation Ecology
