【摘要】 1993年采用α谱仪和大面积屏栅电离定对柴达木盆地盐湖水、地下水、河水以及地表和两个钻孔沉积物中的U，Pu和Am进行了测定。结果表明，各类水样中239Pu（含240Pu，下同）的平均含量高出表层海水约1000倍，其239Pu／238U的活度比在0．001－0．530之间；两钻孔沉积物中239Pu的平均值分别为49±0．8mBq／g和2．4±0．5mBq／g，239Pu／238U的活度比为0．141和0．088，由此探讨了U，Pu和Am的分布特征、239Pu／238U比值的变化规律以及沉积物和水中Pu的来源。更多还原

【Abstract】 In 1993, U, Pu, Am contents were determined by alpha spectrometry and a large-area Screen-grid chamber, for fresh waters (river, well, hot spring and underground waters), salt lake brines and sediments from Qaidam Basin, northwest China. The average contents of transuranium and their variations (represented by the data in parentheses) are as follows: 1) 238U: 2028(5.8-5 380) mBq / L in brines, 420(74-806) mBq/ L in fresh waters, 50(4.3-171) mBq/ g in the sediments of Gasikule Salt Lake (SGSL) and 29(0.13-71) mBq/ g in the sediments of Kunteyi Salt Lake (SKSL);2) 239PU. 7.4(3.1-16.7) mBq / L in brines, 7.9 (2.1-19.7) mBq/ L in fresh waters, 4.9(2.0-18.0)mBq / g in SGSL and 2.4(0.012-5.8)mBq / g in SKSL, 3) 239Pu / 238U average active ratios: 0.085(0.001-0.53) in brines, 0.031(0.004-0.091) in fresh waters, 0.141(0.040-0.91) in SGSL and 0.088(0.022-0.26) in SKSL; 4) 238PU. 0.35(0.20-0.50)mBq/ g in travetine,0.28(0.10-0.78)mBq/ gin SGSK and 0.13(0.05-0.68)mBq/ g in SKSL; and 5) 241Am: 2.26(0.27-4.5)mBq/ L in brines. Pu in the various waters and salt lake’s top layer sediments (within 22m from the bed)originates mainly from nuclear tests and accidents, on the contrary, Pu in salt lake’s bottom layer sediment (22m below the bed) is mainiy from nature nuclear reaction. U in the vdrious waters and sediments is derived from chemical weathering of rocks and minetals around Qaidam Basin.更多还原