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Title: Measurements of thoron progeny concentration using apotential alpha-energy monitor in Japan

Journal Article · · Health Physics
 [1];  [2]
  1. Chubu Electric Power Company, Inc., Nagoya (Japan)
  2. Nagoya Univ. (Japan)

It is reported that thoron concentration in Japanese dwellings may be higher than in other dwellings. Therefore, in order to assess the risk for indoor thoron progeny, the portable potential alpha-energy monitor has been developed. The monitor detects alpha-particles from the {sup 212}Po collected on the filter using a piece of cellulose nitrate film. The detection efficiency of the alpha-particles has been estimated by Monte Carlo calculation. From the results of measurements, the mean indoor thoron progeny concentration in the dwellings was 1.5 Bq m{sup -3} (EC{sub Tn}), and ranged from 0.04 to 8.2 Bq m{sup -3}. The effects of three typical interior walls (soil-based plaster, concrete, and modern materials) on the thoron progeny supply were considered. The mean annual effective dose equivalent was 0.45 mSv. 13 refs., 5 figs., 1 tab.

Sponsoring Organization:
USDOE
OSTI ID:
369951
Journal Information:
Health Physics, Vol. 68, Issue 6; Other Information: PBD: Jun 1995
Country of Publication:
United States
Language:
English