Radioenvironmental survey of the megalopolis lignite field basin

The Megalopolis lignite field basin in southern Greece, with Megalopolis-A and B lignite-firedpower plants in operation (total 900 MW), has been repeatedly investigated during the past 25years by the Nuclear Engineering Section of the National Technical University of Athens (NESNTUA).The present work aims at an integrated radioenvironmental approach leading to the doseassessment to the public and to the plants staff. This approach includes systematic sampling oflignite and barren at the local lignite mines feeding the power plants and sampling of lignite, flyashand bottom ash at the power plants for the determination of the activity of the naturalradionuclides 226Ra, 232Th, 40K, 234Th and 210Pb. Furthermore, the following measurements andsamplings were conducted in 25 selected sites within 10km around the power plants: soil samplingfor the determination of the above radionuclides, radon concentration and exhalation ratemeasurements, soil gas radon concentration measurements, dose measurements and calculations,determination of air-particulate matter concentration etc. The results obtained allowed for themapping of the parameters studied which lead to useful conclusions. Dosimetric calculations forthe population living around the power plants and the plants staff were also performed, based onthe suggestions of [UNSCEAR, 1982].