Almond S, Clancy S A, Davies R J, Worrall F
Centre for Research into Earth Energy Systems (CeREES), Department of Earth Sciences, Science Labs, Durham University, Durham, DH1 3LE, UK.
Environ Sci Pollut Res Int. 2014 Nov;21(21):12316-24. doi: 10.1007/s11356-014-3118-y. Epub 2014 Jun 18.
This study considers the flux of radioactivity in flowback fluid from shale gas development in three areas: the Carboniferous, Bowland Shale, UK; the Silurian Shale, Poland; and the Carboniferous Barnett Shale, USA. The radioactive flux from these basins was estimated, given estimates of the number of wells developed or to be developed, the flowback volume per well and the concentration of K (potassium) and Ra (radium) in the flowback water. For comparative purposes, the range of concentration was itself considered within four scenarios for the concentration range of radioactive measured in each shale gas basin, the groundwater of the each shale gas basin, global groundwater and local surface water. The study found that (i) for the Barnett Shale and the Silurian Shale, Poland, the 1 % exceedance flux in flowback water was between seven and eight times that would be expected from local groundwater. However, for the Bowland Shale, UK, the 1 % exceedance flux (the flux that would only be expected to be exceeded 1 % of the time, i.e. a reasonable worst case scenario) in flowback water was 500 times that expected from local groundwater. (ii) In no scenario was the 1 % exceedance exposure greater than 1 mSv-the allowable annual exposure allowed for in the UK. (iii) The radioactive flux of per energy produced was lower for shale gas than for conventional oil and gas production, nuclear power production and electricity generated through burning coal.
英国石炭纪的鲍兰德页岩；波兰志留纪页岩；以及美国石炭纪的巴尼特页岩。根据已开发或即将开发的井数、每口井的返排液量以及返排水中钾（K）和镭（Ra）的浓度估算值，对这些盆地的放射性通量进行了估算。为作比较，在每个页岩气盆地测量的放射性浓度范围、每个页岩气盆地的地下水、全球地下水和当地地表水这四种情况下，考虑了浓度范围本身。研究发现：（i）对于美国巴尼特页岩和波兰志留纪页岩，返排水中1%超标通量是当地地下水预期通量的7至8倍。然而，对于英国鲍兰德页岩，返排水中1%超标通量（即仅预期在1%的时间内会超过的通量，即合理的最坏情况情景）是当地地下水预期通量的500倍。（ii）在任何情况下，1%超标暴露均不大于1毫希沃特——这是英国允许的年暴露量。（iii）页岩气每产生单位能量的放射性通量低于常规油气生产、核电生产以及燃煤发电。
