Study On Disposal Radioactive Noble Gas Using Absorption Of Active Carbon In Third Qinshan Nuclear Power Company (TQNPC)

During its normal operation, nuclear power plants will produce some radioactive noble gases (Krypton and Xenon). To minimize the release amount of radioactive gases to the environment, they need to be disposed before releasing to the atmosphere.Due to its special structure, active carbon has the ability to absorb the noble gases to its surface and retain them to decay.There are many studies and tests on the technology of treating the noble gas by active carbon. Some developed countries in nuclear technology have already used this technology in their nuclear power plants.TQNPC is the only company in China using this technology. It was originally provided by the Canadian company, Atomic Energy of Canada Limited (AECL). Even though these parameters in the system of active carbon absorption were given, there was no detail on the principles of the parameters controlled, the effects of the parameters varying. Moreover, the some of these parameters in the system could be optimized.China Institute of Radioactive Protection and Shanghai Nuclear Engineering Research and Design Institute performed the studies on absorption of noble gas by active carbon, and published the parameters in their research reports.Based on the system of TQNPC and the data from the above institutes, this paper introduced the system configuration, setting, control and the impact of these parameters (including temperature, pressure,gas velocity and relative humidity) to their corresponding systems.Some suggestions were given to improve the efficiency of off-gas system in the paper, because there were some unreasonable designs in the system. If they are implemented, the absorption efficiency will be expected to increase by over 200%. Once the operation is successful, the experiences can be extended to other nuclear power plants in China.