WASH-OFF EFFECTS IN URBAN AREAS
WASH-OFF EFFECTS IN URBAN AREAS
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DOI：
10.1093/oxfordjournals.rpd.a081051
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发表时间：
1991-01-01
影响因子：
1
通讯作者：
STEGER, F
中科院分区：
文献类型：
--
作者：
MUECK, K;STEGER, F
在切尔诺贝利核泄漏四年后，研究了由于稳定表面的径流和冲刷效应，放射性尘埃在奥地利三个城市的城市地区分布的放射性减少以及由此导致的人口剂量减少，以预测人口的长期外部暴露。在切尔诺贝利事故后，在干沉降物和湿沉降物的比例不同的城市进行了测量，以确定就湿沉降物和干沉降物而言，放射性核素的清除是否存在任何差异。利用高分辨率原位伽马能谱测量了稳定地表上Cs-137和Cs-134的伽马通量，并与未扰动的草地表面进行了比较。与散落后的原始沉积相比，稳定表面上的平面活性平均降低了10+/-5倍。沥青的折减系数最高(11.4)，混凝土的折减系数较小(8.1)，石板和鹅卵石的折减系数仅为4.5左右，砾石几乎没有减少(1.1)。这种还原与干或湿沉积的变化很小。
The reduction of the activity distributed in urban areas in three Austrian cities after a radioactive fall-out, by run-off and wash-off effects from stabilised surfaces and the resulting dose reduction to the population were investigated four years after the Chernobyl fall-out to predict the long-term external exposure of the population. The measurements were performed in cities with different fractions of dry and wet deposition after the Chernobyl accident in order to determine whether any differences in radionuclide removal with regard to wet and dry fall-out was observable. High resolution in situ gamma spectroscopy was employed to measure the gamma flux from Cs-137 and Cs-134 at points over stabilised surfaces, which was then compared with undisturbed grass surfaces. The average reduction of the plane activity on stabilised surfaces amounted to a factor of 10 +/- 5 compared to the original deposition after the fall-out. Asphalt showed the highest reduction factor (11.4), concrete less (8.1), stone slabs and cobblestone only about 4.5 and gravel virtually no reduction (1.1). Only very little variation of this reduction with dry or wet deposition was observed.