Radiological and instrumental neutron activation analysis determined characteristics of size-fractionated fly ash

Radiological risks assessment of building materials ingredients: Palm oil clinker and fuel ash

“…39,68,69 By contrast, the activity concentration of 40 K in POFA is somewhat lower than the POC, it may be due to the differences in particle size of raw POC and POFA. 38 Moreover, the 40 K activity concentration in POC is greater than the world average value of 500 Bq kg À1 , as compiled in the UNSCEAR-1993 report. 39,68,69 Previous study found that the radium and thorium content in decorative materials, i.e.…”

“…The differences in the activity concentration between the POC and POFA samples are due to the radioactive mineral content, origin of materials, the geographical, geochemical and geological variations of soil composition from where the uptake of radionuclides by palm oil plants occurs. 38,67 The difference in activity concentrations of 226 Ra and 232 Th among the palm oil mill wastes are insignificant. One possible reason might be that both of wastes originated from the same sources.…”

“…POC and POFA like inorganic oxides. 38 A number of chemical and physical changes such as the removal of organic ingredients and moisture present in nuts, fibre, shell of palm oil would occur at the time of the combustion process in the boiler, which would lead to enrichment/redistribution of these inorganic oxides 22 and radionuclides in POC and POFA.…”

Environmental radioactivity measurements and applications – Difficulties, current status and future trends

“…210 Pb) will allow for smaller samples, that will (i) reduce sampling effort (ii) allow for the detailed study of radionuclide vertical distributions, which may have further applications (iii) allow for the detailed study of the radionuclide size fractionation in various materials, including NORM. Since specific activity of some radionuclides but also volatile heavy metals and metalloids is higher in the less abundant finer fractions of materials such as soil and NORM (Peppas et al, 2010), the study of this size distribution, together with the study of the quite often significantly disrupted radioactive equilibrium in NORM will allow for a better risk assessment due to emission of NORM in the environment.…”

Μοντέλα Διακίνησης Και Εναπόθεσης Στερεών Σωματιδίων Ιπτάμενης Τέφρας Στο Περιβάλλον Και Συνακόλουθες Ραδιολογικές Επιπτώσεις Στην Λεκάνη Της Μεγαλόπολης

“…Στον ελληνικό χώρο έχουν πραγµατοποιηθεί στο παρελθόν µελέτες ανίχνευσης ιόντων K + σε δείγµατα ϐρόχινου νερού [149], [130], [162]. Με δεδοµένο ότι τα ιόντα K + ϐρίσκονται στην ϕύση σε σταθερή αναλογία µε το 40 K µπορούµε να υπολογίσουµε την συγκέντρω-ση R(Bqgr −1 ) του τελευταίου µε ϐάση την ακόλουθη εξίσωση [146]: ΄Οµως για να αποφανθούµε για τις συγκεντρώσεις των εν λόγω δειγµάτων δεν µπο-ϱούµε να στηριχτούµε µόνο σε αυτές τις µετρήσεις καθώς τα δείγµατα αυτά δεν είναι οµογενή αλλά έχουν αρκετή ποσότητα ιζήµατος, που ϐρίσκεται στην ϐάση των δοχείων.…”