IN-VITRO DETERMINATION OF HT OXIDATION ACTIVITY AND TRITIUM CONCENTRATION IN SOIL AND VEGETATION DURING THE CHRONIC HT RELEASE EXPERIMENT AT CHALK-RIVER
Y. Ichimasa et al., IN-VITRO DETERMINATION OF HT OXIDATION ACTIVITY AND TRITIUM CONCENTRATION IN SOIL AND VEGETATION DURING THE CHRONIC HT RELEASE EXPERIMENT AT CHALK-RIVER, Fusion technology, 28(3), 1995, pp. 877-882
The oxidation activity of molecular tritium (HT) in soils and vegetati
on collected in experimental plots during the 1994 chronic HT release
experiment at Chalk River was determined in in vitro laboratory experi
ments after the release. HT oxidation activity was highest in surface
soils in the natural plot, about 3-4 times that in soils in the cultiv
ated plots. HT oxidation activity in weeds and Komatsuna leaves was ab
out 2 and 0.4 % of that in the cultivated soil, respectively The numbe
r of HT-oxidizing bacteria isolated from soils was highest in the surf
ace soil (0-5 cm) in the natural plot. The viable cell numbers in surf
ace soils in the cultivated and natural plots were almost the same. Th
e total occurrence rates of HT-oxidizing bacteria in the surface soils
were 22 % in the natural plot, and 7.5 % in the cultivated plot. The
occurrence rates of HT-oxidizing airborne bacteria during the release
on two culture media were 4.2 and 1.9 %.