Abstract: The sodium water interaction test facility for small leaks of water intosodium is basically established. Acoustic leak detection system is developed. It issuccessful in sodium boiling detection. Incoloy 800 tubes with small leak (φ0.19,φ0.13 ) is prepared. Rupture disc pressure relief system is successfully deve-loped. It is stable, reliable, sensitive, and convenient for regulating and maintena-nce. It also has rapid response.