Radiological characteristics and investigation of the radioactive equilibrium in the ashes produced in lignite-fired power plants

Karangelos, DJ; Petropoulos, NP; Anagnostakis, MJ; Hinis, EP; Simopoulos, SE

dc.contributor.author	Karangelos, DJ	en
dc.contributor.author	Petropoulos, NP	en
dc.contributor.author	Anagnostakis, MJ	en
dc.contributor.author	Hinis, EP	en
dc.contributor.author	Simopoulos, SE	en
dc.date.accessioned	2014-03-01T01:21:17Z
dc.date.available	2014-03-01T01:21:17Z
dc.date.issued	2004	en
dc.identifier.issn	0265-931X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16181
dc.subject	fly-ash	en
dc.subject	natural radioactivity	en
dc.subject	radioactive equilibrium	en
dc.subject	radon exhalation	en
dc.subject.classification	Environmental Sciences	en
dc.subject.other	NATURAL RADIONUCLIDES	en
dc.subject.other	FLY-ASH	en
dc.subject.other	BEHAVIOR	en
dc.subject.other	GREECE	en
dc.title	Radiological characteristics and investigation of the radioactive equilibrium in the ashes produced in lignite-fired power plants	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.jenvrad.2004.03.009	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.jenvrad.2004.03.009	en
heal.language	English	en
heal.publicationDate	2004	en
heal.abstract	Coal- and lignite-fired power plants produce significant amounts of ashes, which are quite often being used as additives in cement and other building materials. In many cases, coal and lignite present high concentrations of naturally occurring radionuclides, such as U-238, Ra-226, Pb-210, Th-232 and K-40. During the combustion process, the produced ashes are enriched in the above radionuclides. The different enrichment of the various radionuclides within a radioactive series, such as that of 238 U, results in the disturbance of radioactive secular equilibrium. An extensive research project for the determination of the natural radioactivity of lignite and ashes from Greek lignite-fired power plants is in progress in the Nuclear Engineering Department of the National Technical University of Athens (NED-NTUA) since 1983. This paper presents detailed results for the natural radioactivity, the secular radioactive equilibrium disturbance and the radon exhalation rate of the fly-ash collected at the different stages along the emission control system of a lignite-fired power plant as well as of the bottom-ash. From the results obtained so far, it may be concluded that Ra-226 radioactivity of fly-ash in some cases exceeds 1 kBq kg(-1), which is much higher than the mean Ra-226 radioactivity of surface soils in Greece (25 Bq kg(-1)). Furthermore, the radioactivity of Pb-210 in fly-ash may reach 4 kBq kg(-1). These results are interpreted in relation to the physical properties of the investigated nuclides, the temperature in the flue-gas pathway, as well as the fly-ash grain size distribution. It is concluded that towards the coldest parts of the emission control system of the power plant, the radioactivity of some natural nuclides is gradually enhanced, secular radioactive equilibrium is significantly disturbed and the radon exhalation rate tends to increase. (C) 2004 Elsevier Ltd. All rights reserved.	en
heal.publisher	ELSEVIER SCI LTD	en
heal.journalName	JOURNAL OF ENVIRONMENTAL RADIOACTIVITY	en
dc.identifier.doi	10.1016/j.jenvrad.2004.03.009	en
dc.identifier.isi	ISI:000224374800002	en
dc.identifier.volume	77	en
dc.identifier.issue	3	en
dc.identifier.spage	233	en
dc.identifier.epage	246	en