甘肃北山旧井地段高放废物处置库深度初步探讨

PRELIMINARY DISCUSSION ON DEPTH FOR HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY IN JIUJING BLOCK,BEISHAN AREA,GANSU PROVINCE

在对高放废物地下深地质处置库深度确定基本要求的概述基础上,结合甘肃北山旧井地段的地质特征、水文地质特征、岩石力学特征、地应力场特征等方面的情况,分析初始地应力场和二次开挖地应力,对开挖稳定性和发生岩爆的可能性进行计算和预测。研究结果表明,研究区岩体较完整,深度大于400m时地下水补给匮乏且为还原环境,岩石单轴抗压强度较高,总体质量较好;深度小于700m地应力为一般应力场,二次开挖稳定性分析和岩爆分析结果表明在此范围内岩爆发生的可能性不大,依据处置库深度确定的基本要求,初步认为旧井地段处置库的设计深度和地下工程布局应在400～700m范围内进行。

It is very important to confirm the depth and area for high-level radioactive waste(HLW) repository, especially in the HLW concept model and engineering design. The general requirements for determining the depth of the HLW disposal repository are discussed. The geological characteristic,hydrogeological characteristic, rock mechanics characteristic and geostresses characteristic are analyzed in Jiujing block,Beishan area,Gansu Province. Simultaneously,the initial geostresses and the geostresses after excavation are analyzed,and the probability of tunnel stability and rockburst are also calculated and predicted. The conclusion shows that the rock mass is intact;the underground water is short of supply and has a reduce environment 400 m below ground surface;the rock has a high uniaxial strength and the rock mass has good quality. The geostress is a general geostress field range from zero to 700 m below ground surface;and the tunnel stability and rockburst analysis display that the rockburst can not happen in the area from 400 m to 700 m below ground surface. According to the general requirements for the depth of repository,the designed depth of HLW disposal repository should be located in 400-700 m below ground surface.