Estimation of absorbed dose to evacuees at pripyat-city using ESR measurements of sugar and exposure rate calculations.

The external absorbed doses in Pripyat-city resulting from the Chernobyl nuclear power plant accident have been evaluated from eight ordinary granulated sugar samples using the electron spin resonance method. The indoor and outdoor external doses to the people evacuated from Pripyat-city at about 36 h after the Chernobyl accident have been estimated using both data from the eight household sugar samples present in Pripyat-city prior to and during the accident and information on the type of buildings and survey-meter measurements of the exposure rates there. The absorbed dose to the evacuated people, as estimated from the exposure rates calculated in combination with the sugar dosimetry data, agree approximately with the reported average effective dose equivalent to such people, which was derived from both calculations and exposure-rate surveys. If each person in Pripyat-city could remember exactly the proportion of time spent indoors before being evacuated after the accident, the absorbed dose could roughly be estimated from the relationship between the documented external dose outdoors during the period between the accident and evacuation and the length of the period spent indoors by each individual prior to evacuation. It is suggested that as little as 1 g of sugar would be one of the most useful emergency dosimeters for people inside their dwellings, at least for absorbed doses greater than about 0.02 Gy.