建立了用NaI(T1)晶体探测器直接测量大体积水中的弱γ放射性活度在线测量系统,并对该方法的可行性进行了一系列的实验验证。实验结果表明:被测量水体积越大,在同样条件的水中探测效率越高,增大监测水池的容积在一定范围内也是有利的。对于φ100×100 mm的NaI(T1)晶体探测器,实验表 A direct on-line measurement system for the measurement of weak γ activity in large volume of water using a NaI (T1) crystal detector was established. A series of experiments were carried out to verify the feasibility of this method. The experimental results show that the larger the volume of water to be measured is, the higher the efficiency of detection in water under the same conditions is. It is also beneficial to increase the volume of the monitoring pool within a certain range. For φ100 × 100 mm NaI (T1) crystal detector, the experimental table