Milk radioactivity after single intake of technogenic radionuclides in the bodies of domestic animals

The concentration of 131I in the milk of cows taken contaminated forage on 2 May 1986 and fed after that with practically clean dry forage is determined. The maximal 131I-concentration (114 Bq/l) in the milk has been registered in the fist day, then the concentration is decreasing to 6 Bq/l on the eight day. The correlation between the radioactivity of the milk and initially absorbed one is determined; the changing of this correlation has an exponential course and is described with the expression x(t) = 1.4x2-t/1.8, where 't' is the time after single intake of 131I (in days). Hence the period of half-purification of the 131I-contaminated cow milk is 1.8 days. The received regularity allows to forecast the degree of radioactive contamination of the milk after a single internal contamination with enough accuracy. 1 tab