Jiang Shengyao

Cognitive model research of nuclear power plant operators

Abstract Human cognitive reliability (HCR) model is a very useful quantitative model to the reliability research of nuclear power plant (NPP) operators based on simulators. The event non-response probability versus normalized time curve of HCR can be evaluated by statistical distributions such as three-parameter Weibull distribution and lognormal distribution. The paper analyses the HCR model and the characteristics of Chinese NPP operators. Firstly, two-parameter Weibull distribution is used to evaluate the fitting curve of HCR. Then the reliability of NPP operators and the verification of HCR model are studied. The research shows not only the quantitative results of Chinese NPP operators but also a new method to verify HCR model, and can be referred to the real NPP operation, and hence, is of importance to safe operation of NPP.

Effect of pebble size and bed dimension on the distribution of voidages in pebble bed reactor

The HTR-10 built at Tsinghua University is an advanced pebble bed reactor because of its inherent safety and economic efficiency. It is fundamental to explore the voidage of the pebble bed. The existing experimental bed is limited in depth and contains mono-size pebbles. The effects of pebble size and bed dimension of voidage distribution are still not well known. In this work, the discrete element method is used to simulate the static packing of pebbles of three sizes in 2D and 3D pebble beds under the same load. The effects of bed dimension and pebble size on voidage distribution are analyzed. The results are useful for better understanding of the voidage distribution of pebble bed reactor and the effects of bed dimension and particle size as well as the wall effects.

A numerical study of helium-heated inorganic membrane reformer coupling to HTGR

Based on one-dimensional quasi-homogeneous model, a steady-state model and its computer program were developed for helium-heated inorganic membrane reformer coupling to high temperature gas-cooled reactor (HTGR). The results show that the average heat flux of inorganic membrane reformer is 25% higher than that of the conventional one. A compact reformer can be designed, which is significant in making the system safer and more economical. A methane conversion rate of 95% can be achieved by inorganic membrane reformer with a little increase in pressure loss. With thinner membrane and higher sweep ratio, methane conversion rate increases with high reforming pressure, which will change the unfavorable condition of high pressure of HTGR methane reforming hydrogen production system into a favorable one.