Nonuniform Oxidation on the Surface of Fuel Element in HTR

الملخص EN

The graphite oxidation of fuel element has obtained high attention in air ingress accident analysis of high temperature gas-cooled reactor (HTR).

The shape function, defined as the relationship between the maximum and the average of the oxidation, is an important factor to estimate the consequence of the accident.

There are no detailed studies on the shape function currently except two experiments several decades ago.

With the development of computer technology, CFD method is used in the numerical experiment about graphite oxidation in pebble bed of HTR in this paper.

Structured packed beds are used in the calculation instead of random packed beds.

The result shows the nonuniform distribution of oxidation on the sphere surface and the shape function in the condition of air ingress accident.

Furthermore, the sensitive factors of shape function, such as temperature and Re number, are discussed in detail and the relationship between the shape function and sensitive factors is explained.

According to the results in this paper, the shape function ranges from 1.05 to 4.7 under the condition of temperature varying from 600°C to 1200°C and Re varying from 16 to 1600.