210Po is a naturally occurring radionuclide of 238U decay series with a half-life of 138.4 days. 210Po is decay products of 222Rn, which escapes into the atmosphere and present in all environments with aerosol particles. Also, 210Po has high radiotoxicity and emits a high alpha energy of 5.305 MeV, and it decays to finally become a stable isotope, 206Pb. Therefore, 210Po entering the body by continuously ingestion or inhalation is likely to cause severe damage to the bone marrow, kidney and spleen and other sites in the body. Accordingly, the World Health Organization (WHO) recommends that screening level of gross alpha for drinking water not exceed 0.5 Bq·L−1. Alpha spectrometry has been mainly used for analysis of 210Po, and for the accurate measurement of alpha particle with short range, it is essential to prepare suitable source for alpha detection. The 210Po alpha source is made by a spontaneous deposition method in which polonium is adsorbed thin and flat onto a metal disc, such as silver, nickel and copper. There are various pretreatment methods to separate and concentrate polonium from water samples prior to spontaneous deposition, including Fe(OH)3 or MnO2 co-precipitation and evaporation. However, in the case of co-precipitation, sample contamination or loss of polonium may occur through the experimental processes, and evaporation lead to not only time-consuming process but also may cause loss of polonium due to the low boiling point of polonium. Therefore, in order to compensate for these problems, an efficient polonium analysis method that directly collects polonium from the original sample without a pretreatment is required. In this study, 210Po in bottled drinking water sold in Korea was analyzed using alpha spectrometry. A high purity silver disc (99.99%) was inserted into a newly designed polonium deposition kit to quickly and conveniently collect polonium from a water sample. The polonium alpha detecting source was made effectively only by the spontaneous deposition method without a complicated pretreatment. The source was measured using a PIPS detector, and the radioactivity concentration of 210Po was calculated using 209Po as a yield tracer.
알파분광법에 의한 의 정량방법을 검토하였다. 황산염 매질에서 전류세기, 전착시간 및 유기물 첨가제 둥의 변화에 따른 의 전착조건을 찾은 결과 A에서 유기첨가제 없이 시간 동안 전착하는 것이 효율적이었다. 을 4.16 Bq에서 0.0264 Bq(1ng) 까지 전착한 결과 농도가 낮을수록 전착율 및 재현성이 낮아졌으며 1 ng 까지 측정이 가능하였다. 사용후 핵연료 합성용액에서 을 분리한 후 알파분광법으로 측정하여 정량한 결과 (n=4)의 회수율을 나타내었다. 사용후 핵연료 시료용액 중 을 정량하였으며 계산 값과 비교한 결과 10% 이내에서 서로 일치하였다.