Study on radon and radium content in hot spa of higher than 60 0C degrees

Radon and radium content in thermal water of higher than 60 degree C were simultaneously determined by extracting radon into LS toluene solution and counting activity by applying the integral counting method with a LS counter. The activity ratios of radon to radium were found ranging from 0.06 to 0.83 with an average value of 0.23 except only one sample. Radon and radium were also determined for thermal water and accompanying gas at two thermal areas. The latter was divided into uncondensable part and condensed part by cooling. Remarkably large amount of radon and radium were found in them. The activity ratios were also calculated, which were larger than unity. From these results it may be said that even thermal water contains definitely larger amount of radon compared with that in radioactive equilibrium, if inclusive of accompanying gas. The authors conclude from this activity ratio of larger than one that even thermal water of higher than 60 degree C is formed by mixing of ''Rn ground water'' in a certain ratio with original thermal water. Thoron contents were also obtained by analysis of radon decay curve. (author)