The shielding cavity loaded with electronic equipment inside has a high Q value and is in overmode at relatively high frequency as a reverberation chamber (RC), but it does not have stirrers or paddles. However, the electromagnetic environment in the cavity is similar to that in the reverberation chamber working in frequency stirring mode or source stirring mode because of the certain bandwidth of the electronic equipment and the movement of the portable electronic equipment. Therefore, the electric field in the cavity can be predicted based on the theory of reverberation chamber. In order to predict the electric field in a given shielding cavity after loading additional electronic equipment, the determination method of the Q value of the cavity and the absorption cross section (ACS) of the electronic equipment, the influence of the ACS on the Q value of the cavity, and the relationship between the Q value and electric field are analyzed. Firstly, the ACS and radiated emission power of the loading electronic equipment are measured in the RC. Then, the Q value of the cavity with the electronic equipment loaded inside is calculated by the known Q value of the cavity without the electronic equipment and the ACS of the electronic equipment. Finally, the electric field in the cavity loaded with electronic equipment is estimated by using the calculated Q value of the loaded cavity and the measured radiated emission power of the electronic equipment. The experimental results verify the effectiveness of the prediction method.

This paper aims to research the necessity and specific methods to improve the time service of clock system of nuclear power plant. By researching and analyzing the current condition of the whole-plant clock system time service scheme, it propose an improvement scheme of time service system in the aspect of redundancy back-up, system networking, maintenance convenience, and power supply optimization. The research of this paper explores an efficient method to improve time service of clock system and increase reliability. It can provide guidance to the modification of in-service nuclear power plant clock system and the design of new nuclear power plant clock system.

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For arbitrary electrically large cavities, the ideal reverberant frequency is of critical to predict the response of the reference antenna or the electronics inside. To determine the ideal reverberant frequency, this work has carried out a comparison study on the scattering parameter S 11 and S 21 based methods for the general case in reverberation chamber (RC). For the two methods, both of them share the same theoretical basis according to the ergodicity principle, i.e., the ideal field distribution and the commonly used correlation analysis. While for arbitrary electrically large cavities, the S 11 samples rely on the mechanical stirrer (which is not easy to be equipped like that of a classic RC), S 21 samples are more easily recorded by frequency stirring technique. And the corresponding experimental results show that the S 21 based method can provide a more conservative estimate of the ideal reverberant frequency.

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