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The cumulative depositions of 137Cs, 9~ and fallout Pu in the volcanic ash soil of Korea were determined. The average accumulated depositions of 137Cs, 9~ and fallout Pu in the volcanic soil were much higher than those in other forest sites of Korea. From depth profiles, it was found that 137Cs, 9~ and 239.24~ in the volcanic soil are more mobile than those in other forest sites of Korea, and that the downward movement of 9~ is faster than 137Cs and 239'24~ A significant correlation was found between the concentration of 137Cs and those of 9~ and 239'24~ The activity ratios of 238pu/239'24~ and 241pu/239,24~ in soils are close to those observed in the cumulative deposit from the global fallout of nuclear weapon testings.

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Abstract. The radiation shielding calculations were performed for the beam experiment hall of the Proton Engineering Frontier Project (PEFP) in Korea using MCNPX code with nuclear data libraries of the ENDF-B/VII, JEFF3.1, LA150, JENDL-HE, and physics models, Bertini and Isabel built in MCNPX code. The neutron energy spectra from 6 targets (20 MeV/ 1.5 mA-Si, Cu, target, 20 MeV/ 50 uA-Si, 20 MeV/ 4.8 mA-C target, 100 MeV/ 300 uA-Si, W target, 100 MeV/ 10 uA-Si, 100 MeV/ 1.6 mA-C target) were calculated and used as radiation source terms. With these results, the concrete thickness satisfying shielding regulations in Korea was calculated for the target rooms and the building of the Beam Experiment Hall. Bertini, Isabel, JENDL/HE and LA150 nuclear data were applied to the evaluation of the proton induced neutrons. ENDF/B-VII, JEFF3.1, and JENDL/HE nuclear data were applied to the evaluation of the concrete shield.