Study On O-ring For Personnel Airlocks In Nuclear Plant

Personnel airlocks and equipment hatches are important parts of the nuclear power plant containment. As the last safety barriers, they ensure sealing during various normal and accident conditions. The sealing function is achieved by a dual-channel O-ring seal. Reliability of the O-ring is of great importance for maintaining sealing function during accident conditions, and is determined by the service life, hardness and compression ratio of its material.The purpose of this work is to combine with experimental verification, develop O-rings for personnel airlocks in AP1000 nuclear power plant, and to optimize their hardness and compression ratio.Several new O-ring materials were developed and various tests have been conducted to evaluate aging effects in high temperature, radioactive and LOCA environments. A performance test bench was developed for reliability tests before and after aging tests. The aging mechanism is clarified and the relationship is established between material hardness and compression height of O-ring and sealing performances. Experimental results show that after various aging tests, novel O-rings still maintain sealing function. Results also show that sealing function of novel O-rings can be achieved by compression of 1.6mm, and thus the compressing force is greatly reduced in comparing with existing seals.The O-rings are developed according to their reliability and cost to satisfy the requirements of personnel airlocks and equipment hatches in generation III nuclear power plant. The test data obtained in the process provide supports for the design and application of the sealing material in nuclear power plants.