I ran into this interesting article from Australia:
Polluted water leaking into Kakadu from uranium minehttp://www.theage.com.au/national/polluted-water-leaking-into-kakadu-from-uranium-mine-20090312-8whw.html
THE Ranger uranium mine inside the World Heritage-listed Kakadu National Park is leaking 100,000 litres of contaminated water into the ground beneath the park every day, a Government appointed scientist has revealed....
Environmentalists and the Greens say the company should be forced to halt plans to expand the mine until it explains how it intends to recover the water and meet its obligations to rehabilitate the world heritage-listed area, 250 kilometres south-east of Darwin. "The Ranger mine has a long history of cutting corners with worker and environmental safety standards and this latest leak means permanent pollution in Kakadu," said the Australian Conservation Foundation's nuclear campaigner, Dave Sweeney.
"Federal authorities should require ERA to end their expansion plans, phase out current mining, get serious about cleaning up the mountain of mess it has already caused and get out of Kakadu."
Some things immediately stood out as being odd:
- We are told the amounts of water released (100,000 litres!), but not the concentration of contaminants in it
- We are not told what the contaminants are
- We are not told what concrete ecological effects these pollution has had or is expected to have on the surrounding marsh
Which is odd, because if I were writing about an environmental catastrophe, I'd squeeze out every gory detail for its maximum shock value. But here, no details! So I dug in. My starting point was found via wikipedia: it is a summary of Ranger mine contamination by a critical audience,
Environmental Incidents at Ranger – update August 2002http://www.aph.gov.au/Senate/committee/ecita_ctte/completed_inquiries/2002-04/uranium/report/e06.pdf
Compiled by Friends of the Earth, Australian Conservation Foundation and the Sustainable Energy & Anti-Uranium Service Inc.
(The host is Australian parliament - I guess this was submitted as evidence by the groups.)
Figure 3: Map of Ranger mine water monitors
[Australia Department of the Environment and Water Resources]
The gist of it seems to be two things: soluble uranium salts, and acidity from sulfuric acid. (N.B. this is from 2002, not recent, but it's a starting point.)
On uranium ions: the worst grievances they bring up - the highest concentrations (if I haven't missed one) - are
April - It was discovered that further runoff from the Low Grade Ore stockpile - which was supposed to have been redirected - had uranium at 13,785 μg/L and was entering the headwaters of Corridor Creek.
General - The uranium contamination of RP1 during the 1998/99 Wet Season is the closest ERA has yet come to exceeding their operating requirements. Although the total mass of uranium discharged is below (high) legal limits, the low flows in Magela Creek during the early discharges from RP1 almost led to ERA increasing the U concentration in the Magela greater than the 3.8 μg/L allowed. The U and SO4 levels in the Magela at the Kakadu National Park border are higher than background.
Straightaway there's an obviously important distinction: between the concentration of runoff at at the point of leak, and in the natural water body after massive dilution. For the former, the highest value they mention is 14 ppm - and there you see the "contaminant" in question is already extremely dilute, 0.0014% U salts in water. For the latter, the meaningful number, the highest peak value they report - which they admit is WITHIN safe levels (defined by Australia as 6 parts per billion - US drinking water levels are 30 ppb by the way) - is 3.8 ppb, in a nearby creek.
This bugs me. The Age warned us that hundreds of cubic meters of quote "contaminated water" are leaking out, without the caveat that said contamination is already extremely dilute. And some are far lower - one of the grievances is a leak containing just 70 ppb U at its point of origin, which is pushing the limits of ridiculousness.
Now, here I'll abandon the activists and let the numbers speak for themselves. I found the web page for Australia's environmental department, and it turns out not only do they monitor water all around the Ranger mine, they publish all their data online, in accessible, graphical form.http://www.environment.gov.au/ssd/monitoring/map.html
Figure 3 is their map of the monitoring sites around Ranger.
They have three chemistry-monitoring sites around Ranger. Here is the Magela Creek one mentioned:
I can't say it better than they do - "Please note that the limit is far above the range shown on the charts, but the scale on the right hand axis shows how the measured concentrations compare to the limit." Aha!
That The Age article, published March 13, 2009? You can see where those leaks happened - the tallest peak around Mar. 01. Creek levels reached around 370 parts per trillion (!!!), 1/20th of regulatory limits and 1/100th of US drinking water limits (see below for source).
I don't think I should dwell on how incredibly trivial this contamination is, or how dishonest The Age appears to have been in not quantifying its extent.
On 18 February, uranium was approximately 6 per cent of the limit and measured 0.37 µg/L at the downstream site compared to 0.028 µg/L at the upstream site. This concentration is similar to uranium concentrations measured by the creekside field toxicity monitoring program on two occasions in 2002/2003 and once in the 2006/2007 wet season. On each of these occasions, field toxicity monitoring (including the in situ test conducted 16 – 20 February, 2009) has shown no biological effects.http://www.environment.gov.au/ssd/monitoring/explanatory-chem.html#season0809
For comparison; I found this DoE page, referencing a natural U concentration for a river in Ohio. It is 1 ppb. That is, this unremarkable river has natural uranium levels three times the highest levels achieved in that newsworthy mine leak.http://www.lm.doe.gov/land/sites/oh/fernald_orig/Cleanup/WaterBypass.htm
The background uranium level in the Great Miami River upstream of the Fernald site is 1 ppb. Background level refers to concentrations of substances found naturally in the environment. Based on historic data, Fernald’s discharge has the potential to increase the uranium level in the river by approximately 4 to 5 ppb, depending on the river’s level.
In November 2000, EPA established the final federal drinking water standard of 30 ppb, a level that was determined to be protective of human health and the environment. With EPA’s approval, DOE adopted the 30 ppb uranium drinking water standard as the performance-based discharge limit and the aquifer cleanup level in December 2001.
The natural levels in the Magela creek (e.g. the "upstream" data) seem to average around 0.02 ppb, much lower than in Ohio (local geology?)
Some other interesting benchmarks are the natural uranium concentrations in - seawater, 3.2 ppb; the earth's crust, 2-4 ppm; and topsoil, 0.7-11 ppm.
Likewise, the pH doesn't seem to be any different than upstream levels - no massive acidification in the creeks (fig. 5).
Anyway, I think this is another example of hypersensitivity to nuclear things. As far as I can interpret, the environmental and health effects of this Ranger contamination are negligible. Yet tiny, harmless leaks are strung about as an ecological disaster, while every other sort of mining - coal, copper metal, and yes wind turbines (lanthanides for permanent magnets) and solar panels (waste sludge of silicon tetrachloride) are complacently ignored.
And how much coal mining does Ranger displace? At 4,500 tonnes uranium per year (5,500 tons U3O8), it is responsible for a tenth of the world's uranium production. At 3% enrichment, this would yield 1,000 tons of low-enriched uranium; and with 40 MWd(thermal)/kg burnup and 33% efficient steam turbines, the electricity dependent on Ranger I estimate as 300 billion kWh/year, or $30 billion/year in value at US rates. And the coal displaced is ~100 million tons per year, 2% of the world's coal mining.
Actually there is a trick with which you can improve nuclear reactor's fuel efficiency by 10,000%; this would somewhat lower the amount of mining needed.