Radiation and Nuclear Safety Authority - STUK, Helsinki, Finland.
J Environ Radioact. 2011 Aug;102(8):780-7. doi: 10.1016/j.jenvrad.2011.04.011. Epub 2011 May 14.
Liming of lakes is considered one possible remedial action to reduce the accumulation of radionuclides into fish in the case of a radiological accident. These responses were tested in field conditions in a small acidified lake that was divided into two parts: one limed with CaCO(3) and the other half left as an unlimed control. The transfer of (90)Sr from water into fish decreased on average by 50% during the first year after liming. However, at the same time the (90)Sr concentration in water increased, reaching a maximum within 6 months after liming. Approximately 50% more (90)Sr was detected in water in the limed part of the lake than on control side during the first year. (90)Sr was most probably released from the sediment as the Ca concentration and pH of the water increased. As a result of these two processes, which counterbalanced each other (increased release of (90)Sr into water from sediment and decreased transfer of (90)Sr from water into fish), the (90)Sr concentration in fish did not notably differ between the limed and control sides of the lake. Liming may only be suitable as a remedial action if carried out immediately after a radiological accident, before significant amounts of radionuclides have been deposited in lake sediments. In the case of (137)Cs, the effect of liming was less pronounced. (137)Cs activity concentration in water increased in the first year by 20% and uptake by fish decreased by 20%.
湖泊的石灰化被认为是减少放射性事故中放射性核素在鱼类中积累的一种可行的补救措施。这些反应在一个小型酸化湖泊的野外条件下进行了测试，该湖泊被分为两部分：一部分用 CaCO3 进行石灰化，另一半作为未石灰化的对照。石灰化后第一年，（90）Sr 从水中向鱼类的转移平均减少了 50%。然而，与此同时，水中的（90）Sr 浓度增加，在石灰化后 6 个月内达到最大值。在第一年，湖中石灰化部分的水中（90）Sr 浓度比对照侧高约 50%。（90）Sr 很可能是由于 Ca 浓度和水的 pH 值增加而从沉积物中释放出来的。由于这两个过程相互抵消（从沉积物中向水中释放更多的（90）Sr 和从水中向鱼类转移（90）Sr 的减少），湖中石灰化和对照侧的鱼类（90）Sr 浓度没有明显差异。如果在放射性事故发生后立即进行石灰化，并且在湖底沉积物中没有大量沉积放射性核素，那么石灰化可能只是一种补救措施。对于（137）Cs，石灰化的效果不那么明显。水中（137）Cs 活性浓度在第一年增加了 20%，鱼类的摄取量减少了 20%。
