238,235U, 232Th과 40K의 베타선 및 감마선에 의한 토양의 흡수선량 환산 인자

Abstract

Dose rate conversion factor was calculated to estimate the absorbed effective annual doses for soilsfor the beta-rays and gama-rays, which were emitted from 238,235U, 232Th, and 40K isotopes. The most recentdata of the emitted energies per decay, half-lifes, and branching ratios, which were obtained from NationalNuclear Data Center, were used. When this factor and the effective annual doses for the beta-rays and the238U, 232Th and 40K areestimated to have good agreements but a large difference is shown in this for 235U. Through the calculationsof effective annual doses by using these factor and the measurements of gama-ray spectra for soils, whichwere extracted from prehistoric remains.(Mansuri) on Osong, Chungchengbuk-do, The annual effective doses. Corresponding authorPhone : +82-(0)42-868-3665 Fax : +82-(0)42-868-3393E-mail : gdkim@rock25t.kigam.re.kr238,235U, 232Th. 40K. ... . .... .. ... .... .. .. 461Vol. 20, No. 6, 2007were obtained to be 3.8~5.9 mGy/yr. Also, when these doses including decay elements upper Rn were comparedwith those on all isotopes, the diferences within 9~30 % were obtained. The analysis method of the annualeffective doses for the beta-rays and the gama-rays of the natural isotopes of soils was established by thisdose rate conversion factor.