Experimental optimization of physicochemical factors for spontaneous deposition of Po using newly designed deposition kit.

A simple spontaneous deposition kit for Po determination using alpha spectrometry was newly designed, and polonium deposition characteristics under various physicochemical conditions were evaluated using it. The high-purity silver disc (99.99%) showed high deposition efficiencies of over 85.

Rapid sequential determination of Rn and Ra in drinking water by liquid scintillation counting.

Since daily drinking water is one of the major source for the ingestion of radiotoxic Rn and Ra, the demand for a simple method to determine these two radionuclides has significantly increased. In the present study, a rapid, simple sequential analysis method for determining Rn and Ra in drinking water using a liquid scintillation counter was developed. The method employs solvent extraction and correction equations for the effect of native Rn for Ra analysis.

Preparation and evaluation of new reference materials for naturally occurring radioactive materials (NORM): Zirconium silicate, bauxite, and phosphogypsum.

New reference materials (RMs), zirconium silicate, bauxite and phosphogypsum, were produced and characterized according to an ISO guide. The homogeneity of the three RMs was evaluated using X-ray fluorescence (XRF), and characterizations of the three candidate materials were performed through a collaborative study with nine expert radioanalytical laboratories. The assigned radionuclides are Th, Th, U, U, and U for zirconium silicate; Th, Th, U, and U for bauxite; and Ra, Th, U, and U for phosphogypsum.

Large seasonal variations in fine aerosol precipitation rates revealed using cosmogenic Be as a tracer.

To determine the seasonal variations in the removal efficiency of fine aerosols (PM2.5) in the Northeast Asia, we analyzed Be data collected for the surface air and precipitation over 20 years in Korea. The Be activity concentrations in the surface air were relatively higher in spring owing to tropopause folding but lower in summer owing to efficient removal by precipitation.

Characteristics of artificial radionuclides in sedimentary soil cores from a volcanic crater lake.

The distributions of Cs, Np, and Pu activity concentrations in sedimentary soil cores of the volcanic crater-lake have been studied. The Pu/Pu atom ratios measured by MC-ICP-MS and mutual activity ratios were examined. These results were used to evaluate the sedimentation characteristics of the crater-lake (Baengnokdam of Mt.

Dispersion and removal characteristics of tritium originated from nuclear power plants in the atmosphere.

The activities of tritium in water-vapor (n = 649) and precipitation (n = 2404) samples were measured from 1998 to 2015 around the Wolsong nuclear power plant (NPP) site where four pressurized heavy water reactors and two pressurized water reactors operated. The activity concentrations of tritium in the water-vapor and precipitation samples were in the ranges of 2.2-2200 Bq/L and 0.

7Be in ground level air in Daejeon, Korea.

(7)Be concentrations in the ground level air in Daejeon, Korea were determined during the period of January 1998 to December 2009 by gamma-ray spectrometric analysis of particulate samples collected on filter paper with a high-volume air sampler. The monthly concentrations of (7)Be in the ground level air were in the range of 1.3-7.

Distribution of tritium in water vapour and precipitation around Wolsung nuclear power plant.

The distribution of tritium in water vapour and precipitation with discharge of tritiated water vapour and meteorological factors was studied around the Wolsung nuclear power plant (NPP) site during the period 2004-2008. The tritium concentrations in atmospheric water vapour and precipitation had a temporal variation with relatively high values in the early summer. Spatial distribution of tritium concentrations was affected by various factors such as distance from the NPP site, wind direction, tritium discharge into the atmosphere and atmospheric dispersion factor.