Measurement of resuspended aerosol in the Chernobyl area - Part II. Size distribution of radioactive particles
Measurement of resuspended aerosol in the Chernobyl area - Part II. Size distribution of radioactive particles
复制标题
DOI：
10.1007/s004110050082
复制
发表时间：
1998-02-01
影响因子：
1.7
通讯作者：
Tschiersch, J
中科院分区：
文献类型：
--
作者：
Garger, EK;Kashpur, V;Tschiersch, J
使用多个级联撞击器在切尔诺贝利 30 公里禁区的两个地点进行了颗粒放射性核素的尺寸分布测量。根据吸入剂量评估中对数正态活动大小分布的一般假设，对 1986 年 9 月至 1993 年 6 月期间获得的结果进行了讨论。在 Zapolie（距离切尔诺贝利反应堆 14 公里的地点），91% 的测量分布都观察到双峰分布。在大多数情况下，中值约为 4 μm，范围为 20-30 μm。根据土壤粒度数据，这一发现可以通过叠加两个过程来解释：局部再悬浮和来自高度污染地区的放射性气溶胶的平流输送。自事故发生以来，平均空气浓度显示可吸入颗粒物的比例逐年增加。 1983 年，可吸入部分约为总浓度的 48%。在位于高度污染地区的普里皮亚季，Cs-137 的粒径分布以单峰型为主，中值直径在 5-10 μm 范围内。对于三种核素 Cs-137、Ce-144 和 Ru-106，观察到非常相似的分布类型。显然，放射性气溶胶是由燃料产生的。在距离 17 公里的森林火灾中，大部分放射性与中值直径在 0.28-0.50 微米范围内的亚微米颗粒有关。
Size distribution measurements of particulate radionuclides were performed at two sites in the Chernobyl 30-km exclusion zone using several cascade impactors. The results obtained in the period September 1986 till June 1993 were discussed with regard to the general assumption of a log-normal activity size distribution in inhalation dose assessment. At Zapolie (a site 14 km from the Chernobyl reactor) a bimodal distribution was observed in 91% of all measured distributions. In most cases the medians were about 4 mu m and in the range 20-30 mu m. According to soil granulometric data this finding was explained by superimposing two processes: local resuspension and advective transport of radioactive aerosol from highly contaminated territories. The mean air concentration showed an increasing proportion of inhalable particles over the years since the accident. In 1983 the inhalable fraction was about 48% of the total concentration. At Pripyat, a site situated within a highly contaminated area, unimodal types of size distributions were predominant with the median diameters in the range 5-10 mu m for Cs-137. For the three nuclides Cs-137, Ce-144 and Ru-106, very similar types of distribution were observed. Apparently, the radioactive aerosol was of fuel origin. During a forest fire at a distance of 17 km, the majority of the radioactivity was associated with submicrometer particles with median diameters in the range 0.28-0.50 mu m.