阻塞计和冷阱是钠中杂质在线监测及控制的重要设备。在快堆一次辅助系统中,因一次钠本身被活化及其载带有裂变产物、腐蚀产物,在冷阱、阻塞计等一次辅助设备中形成较强的放射源。一旦发生设备泄漏,一次钠形成的钠蒸汽即成为气体放射源,弥散 Blocking meter and cold trap is an important equipment for on-line monitoring and control of impurities in sodium. In an auxiliary system of a fast reactor, a primary radioactive source is formed in a secondary device such as a cold trap, a choke meter and the like due to the primary sodium itself being activated and containing fission products and corrosion products. In the event of equipment leaks, the sodium vapor formed by a sodium becomes a gaseous radioactive source and diffuses