Site Evaluation Study at Beishan, NW China-a Potential Site for China High Level Radioactive Waste Repository

摘要

The final safe disposal of high level radioactive waste has been a challenging task forrnthe sustainable development of nuclear industry in China. It is estimated from thernChinese nuclear power plan that the accumulated spent fuel will be 1,000 tons by 2010,rnwhile 2,000 tons by 2015. The spent fuel in China will be reprocessed first, followed byrnvitrification and final geological disposal. The repository will be a shaft--tunnel model,rnlocated in saturated zone in granite. The Beishan area, Gansu province, is thernpreselected area for China's high level radioactive waste repository. The geologicalrncharacteristics of the Beishan area shows that the crust in the area is stable, and it has arngreat potential for the construction of a high level radioactive waste repository. In thernarea, 8 granite blocks have been selected as potential sites for the future URL and HLWrnrepository, while the Jiujing block, the Xiangyangshan block and the Yemaquan blockrnhave been chosen as the 3 most potential sites. Detailed work has been concentrated onrnthem. The Jiujing Section is one of the potential blocks to host a site-specificrnunderground research laboratory and a HLW repository in the Beishan Area. Based onrnthe previous results, 2 bore holes, which are the first in Beishan, were planned in thernperiod of 1999--2001. BS01 is a vertical hole with a depth of 703.08 meters, drilled tornevaluate the potential Bantan Granite Unit, while BS02 an inclined one with a depth ofrn500 meters, focused to evaluate the characteristics of the key NE-striking Shiyuejingrnfaul. The drilling for BS01 started on July 8, 2000 and completed on October 20, 2000.rnBore hole television, bore hole geophysical survey (gamma, resistivity, temperature,rnpressure, U, Th and K content, full waveform sonic, bore hole televiewer), pumpingrntests, injection tests and sample-taking and geostress measurement have been conducted.rnIn the coming 5-year period (2001-2005), other 2 blocks, the Xiangyangshan Block andrnthe Yemaquan Block, will also be investigated, including surface geological mapping,rngeophysical survey and at least 3 bore holes. In about 2005, a candidate site for ourrnsite-specific underground research laboratory will be proposed, and further work willrnbe conducted continuously.