三朝温泉水配管内の温泉沈殿物について（第3報）（付三朝分院飲泉水分析）

鳥取県三朝温泉岡大源泉の配湯管内の温泉沈殿物について既に報告されているが，今回採取した黒色の温泉沈殿物について発光分析法による定性分析を行ったところ，強放射性鉱物である北投石の主成分のBaが高濃度に検出されたので，岡大源泉（飲泉）水および沈殿物中の主要成分および放射能について調査した。温泉水のpHは6.97，Rn-222濃度は190.9Bq./kgで，Mn，Fe，Baの濃度は夫々0.011，0.018，0.021（mg/kg）であり，泉質は弱放射能-ナトリウム-塩化物泉に該当した。沈殿物中の主要成分はMn，Fe，Baで，その濃度は夫々363.5，148.0，69.6mg/gであり，このBa濃度は三朝温泉の温泉沈殿物中最高の濃度であった。しかしRa-226濃度は，既報程 度の3.30×10(-8)Ci/kgであった。

The hot spring waters of Okadaisen and the sinter deposit in the distributing pipe which was used for about 20 years were investigated. The analysis of the spring waters and the sediment were mainly carried out by Spectraspan emission spectrophotometer. Radium-226 in the sinter deposit and radon-222 in the spring waters were measured by vibrating reed electrometer and liquid scintillation counter, respectively. As the results of the analysis, this spring waters were classified into weakly radioactive sodium-chloride waters. It also contained 3.73mg/kg of F and 190.9 Bq./kg of radon-222. The major components of this deposit were characterized with regard to high concentration of Mn (363.5mg/g), Fe (148.0mg/g), and Ba (69.6mg/g). Ra-226 concentration of the sinter deposits of Misasa hot springs in previous reports were 6.24×10(-12)～5.74×10(-8) (Ci/g), but its concentration in this report was 3.30×10(-8) Ci/g. It seems that a linear correlation is recognized between radium-226 and (Fe+Mn) concentrations in the sinter dedosits of Misasa hot springs.