Effect on radioactivity concentration estimation of radon progenies with NaI(Tl) pulse height distribution from considering geometric structure around detector and infiltration of radionuclides.
The surface radioactivity concentrations of the radon progenies, (214)Pb and (214)Bi, were estimated from NaI(Tl) pulse height distributions during rain. The improvement in estimation errors caused by considering geometric structures around measuring points and infiltration of radionuclides was discussed. The surface radioactivity concentrations were determined by comparing the count rates at the full-energy peak ranges between observation and calculation with the electron-photon transport code EGS5. It was shown that the concentrations can be underestimated by about 30 % unless the obstacles around the detector or infiltration of radionuclides are considered in gamma ray transfer calculations at measuring points, where there are many tall obstacles, or the ground is covered with unpaved areas.
Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan hirouchi.jun@h.mbox.nagoya-u.ac.jp.
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J
Hirouchi
Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
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Y
Terasaka
Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
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S
Hirao
Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
J
J
Moriizumi
Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
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H
Yamazawa
D000396:Air Pollutants, Radioactive / Q000032:analysis*; D000465:Algorithms; D011829:Radiation Dosage; D017687:Radon Daughters / Q000032:analysis*; D011891:Rain / Q000737:chemistry*; D015203:Reproducibility of Results; D012588:Scintillation Counting / Q000295:instrumentation* / Q000379:methods*; D012680:Sensitivity and Specificity; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D000396:Air Pollutants, Radioactive; D017687:Radon Daughters; D014875:Water Pollutants, Radioactive