engleski

Natural radionuclides in slag/ash pile from coal-fired power plant Plomin

The investigated coal slag and ash pile contains about million tons of different waste material deposited in vicinity of Plomin coal fired power plant. The levels of natural radioactivity in the slag and ash pile depend on different kinds of coal used for the plant operating. Activities of 40K, 232Th, 226Ra and 238U in materials deposited on slag/ash pile as well as in used coal were occasionally measured during past more than two and half decades of Plomin coal-fired plant operation. The radionuclides content in deposited bottom and filter ash material are related with radionuclide activities and mineral matter fraction in coals used. Up to the beginning of nineties, the majority of coal used was anthracite from Istrian local mines. In that period, deposited waste material was characterized with relatively high 226Ra and 238U activities while potassium and thorium content was very low (40K activity was 2-9% of total activity, 232Th 1-3%). When Istrian coal has been completely substituted with imported coal, uranium series radionuclide concentrations in deposited waste materials decreased significantly. Meanwhile, potassium and thorium activities in slag and ash pile material increased. It seems that slag and ash pile pile material generated in the last several years of Plomin coal fired power plant operation could be generally used in cement industry without any special restriction.

coal; slag and ash; radioactivity; CFPP

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