China's first plant for the vitrification of radioactive waste has been officially put into operation in the city of Guangyuan, Sichuan Province, according to the China Atomic Energy Authority (CNEA).
Xinhua reported on 14 September that a test run had begun on 27 August and the first tank of solidified glass was produced from liquid radioactive waste. The project headquarters stated that the facilities of the plant have met relevant operating conditions and deemed it fit to start formal operation from 11 September. The project was approved by CNEA in 2004. It was designed jointly by China and Germany.
"The disposal of radioactive waste is the last step in the safe use of nuclear energy. The most technically difficult process is disposal is of high-level radioactive waste,", CNEA chief engineer Liu Yongde told reporters. He said process takes place at 1100 degrees Celsius or more. At high temperature, the radioactive waste liquid and the glass raw material are mixed and melted, and the glass body is formed after cooling. It involves a glass curing formula with high containment rate and good stability, so that the glass product can contain radioactive materials for more than a thousand years, he noted. This requires a furnace that can withstand high temperatures above 1150 degrees and which has an annual corrosion rate of less than 15 mm.
It is an automated process which uses remotely operated equipment. China National Nuclear Corporation Sichuan Environmental Protection Co Ltd was responsible for the construction. After the facility is put into operation, it is expected that hundreds of cubic metres of high-level liquid waste can be safely processed each year. The vitrified product will be buried in a repository hundreds of metres deep underground.