Nielsen S P, Gryning S E, Karlberg O, Lyck E, Thykier-Nielsen S
Risø National Laboratory, Roskilde, Denmark.
Health Phys. 1990 Mar;58(3):283-9. doi: 10.1097/00004032-199003000-00006.
Double tracer experiments were made in May 1981 at the Ringhals nuclear power plant in Sweden to investigate atmospheric-dispersion and dose models. Sulphurhexafluoride (SF6) and radioactive noble gases were released simultaneously from a 110-m stack and detected downwind at distances of 3-4 km. The experiments were made under near-neutral conditions. One-hour measurements at ground level yielded cross-wind profiles of SF6 concentrations and gamma radiation from the plume. In-situ gamma spectrometric measurements demonstrated a significant surplus of gamma rays from the noble gas daughters (88Rb and 138Cs) compared with those from the noble gases. This surplus was interpreted as due to dry deposition from the plume, and deposition velocities were estimated at 0.02-0.10 m s-1. These values are very high when compared with values recommended for calculating consequences of nuclear accidents. The high values are believed to be due to the very small size of the daughter particles.
1981年5月，在瑞典的灵哈尔斯核电站进行了双示踪剂实验，以研究大气扩散和剂量模型。六氟化硫（SF6）和放射性惰性气体从110米高的烟囱中同时释放，并在3 - 4公里外的下风向进行检测。实验在近中性条件下进行。在地面进行的一小时测量得出了六氟化硫浓度的侧风剖面图以及羽流中的伽马辐射。现场伽马能谱测量表明，与惰性气体相比，惰性气体子体（88Rb和138Cs）产生的伽马射线有显著盈余。这种盈余被解释为是由于羽流的干沉降造成的，沉积速度估计为0.02 - 0.10米/秒。与用于计算核事故后果所推荐的值相比，这些值非常高。据信，高值是由于子体颗粒非常小所致。
