A large tunnelling machine has begun drilling the sloped spiral ramp of the Beishan Underground Research Laboratory near Jiuquan City in China's Gansu province. The laboratory - in the Gobi Desert - will comprise the spiral ramp, three vertical shafts and horizontal disposal galleries.

The Beishan No.1 tunnelling machine (Image: CNNC)

The world's first "large-slope spiral tunnel hard rock tunnel boring machine" - known as Beishan No.1 - began drilling the laboratory's underground ramp on 18 November, China National Nuclear Corporation (CNNC) announced.

The Beishan No 1 machine is about 100 metres in length and has a diameter of just over seven metres. It can achieve a horizontal turning radius of 200 metres and a vertical curve radius of 380 metres.

"This marks the beginning of the construction stage of the first spiral ramp in the world that adopts the continuous small-turn, large-slope full-face hard rock tunnel boring machine construction method, providing technology for the high-quality construction of an internationally advanced and world-class underground laboratory," CNNC said.

The Beishan Underground Research Laboratory - which will be situated in granite up to 560 metres below ground level - will be used to test the suitability of the area for the long-term storage of the high-level radioactive waste.

A ground-breaking ceremony was held at the Beishan site in June 2021.

The laboratory was one of 100 major scientific construction projects listed in China's 13th Five-Year Plan, covering 2016-2020. In 2019, the project was approved by the China Atomic Energy Authority, with CNNC's Beijing Institute of Geology of the Nuclear Industry designated as the leader of the project.

The laboratory's surface facilities will cover 247 hectares, with 2.39 hectares of gross floor space. The underground complex will have a total structural volume of 514,200 square cubic metres, along with 13.4 kilometres of tunnels.

The laboratory is estimated to cost over CNY2.72 billion (USD377 million) and take seven years to build. It is designed to operate for 50 years, and if its research proves successful and the site is suitable, an underground repository for high-level waste will be built near the laboratory by 2050.

Researched and written by World Nuclear News