Abstract:
The HANARO CNS adopts the liquid hydrogen as a moderator. The liquid hydrogen contained in the moderator cell evaporates due to gamma heating. The hydrogen vaporizes up to the condenser, where it is re-liquefied then it returns down to the moderator cell. This thermo-siphon loop can only be established under the very low temperature environment, which requires a method for a thermal insulation. Therefore, the processing system of the CNS basically consists of a Hydrogen System, a Vacuum System, a Gas Blanketing System, a Helium Refrigeration System, and a Control System. The overall design concept of the CNS is to ensure that the reactor safety systems and the on-site personnel and equipment are not adversely affected by the hydrogen-oxygen reaction from the CNS. The safety design criteria of the CNS is a defence-in-depth approach that provides several means to avoid any accidental contact between the hydrogen in the system and the air. Therefore, the principles of a conservatism, simplicity, redundancy, fail-safe design, and passive safety features are included to design it with an enhanced safety and efficiency. This paper presents the design characteristics of the HANARO Cold Neutron Source and the architectural design related to the reactor building.