[cdn-nucl-l] Re: Falling rocks and floods: uranium miner's concerns

[Muckerheide <muckerheide@attbi.com>]

Thanks Jerry, but I'm still curious about my question? Was there an
"environmental impact" prevented, at what cost, by putting processing
underground?  

(And I'd be infinitely more interested in the answer to the more rational
question if a miner asked a "senior radiation biologist" what concerns he
had about exposure to radiation. Would the answer have been as intelligible?
(Would more than 2 "sr rad bios" produce a credible answer? :-)

Thanks, Jim

on 5/18/03 3:20 PM, Jerry Cuttler at jerrycuttler@rogers.com wrote:

> Jim,
> 
> The uranium concentration in the McArthur River ore is extraordinary (> 20% vs
> 0.1% in most uranium mines)!  So I would expect the gamma radiation level and
> the rate of radon emission to be much higher than for most mines.
> 
> One of our senior radiation biologists asked a miner recently what concerns he
> had about exposures to radiation in uranium mines.  He said that he was much
> more concerned about big rocks falling down on him.  I expect that he is now
> concerned about flash floods too.
> 
> Special safety measures are in place to avoid injuries to workers.
> 
> Jerry
> ----- Original Message -----
> From: Muckerheide
> To: Jerry Cuttler ; cdn-nucl-l@informer2.cis.McMaster.CA
> Cc: mbrexchange@list.ans.org
> Sent: Saturday, May 17, 2003 2:35 PM
> Subject: Re: [cdn-nucl-l] Water flows into McArthur River uranium mine
> 
> 
> Is this (underground processing) another case where "heroic" and costly (and
> double standard) measures are taken to reduce "environmental impacts" in
> nuclear applications that then also come back to fail and add grotesque
> costs and reinforce misperceptions of false "dangers" of radiation and
> nuclear technologies to the public?
> 
> Also how does the "environmental impact saved" compare to coal mining that
> successfully prevents constraints on removing whole mountains and dumping
> them in valleys?  (Or normal operation of a typical large coal-fired power
> plant?)
> 
> Regards, Jim
> 
> on 5/17/03 12:10 PM, Jerry Cuttler at jerrycuttler@rogers.com wrote:
> 
>> Recently this problem has been brought under control and uranium mining may
>> resume within several months.
>> Jerry
>> ---------------------------------------------------------
>> 
>> Water flows into McArthur River
>> Nuclear Engineering International  -  17 May 2003
>> 
>> Production has been suspended at Cameco's McArthur River in Canada, the
>> world's largest high-grade uranium mine, because of flooding in the mine.
>> 
>> McArthur River was carved out of basement rock surrounded by porous
>> Athabasca sandstone. Water constantly flows in and is pumped out of the
>> mine, but a sophisticated refrigeration system is used to freeze the
>> surrounding ground and keep producing areas dry.
>> 
>> In an area where the freezing system was not yet installed, grouting
>> reinforcing concrete retaining walls were being carried out, and rounding
>> ground. Cracks were seen in the retaining walls, and the mine was evacuated.
>> Water began to gush into the tunnel on 6 April.
>> 
>> The mine's pumps have been running around the clock, and additional pumps
>> have been brought in. Provincial and federal regulators have been at the
>> site, monitoring the flow of water into the mine and surface treatment
>> facilities. Water pumped from the mine contains chemicals such as radium,
>> and must be treated before it is placed into settling ponds.
>> 
>> Cameco president Gerald Grandey said the situation was "critical" and the
>> shutdown would last at least a couple of months. In a later update, he said
>> the company had underestimated the amount of water going into the mine and
>> that this year's production would be "well below" its annual capacity. He
>> also said that increased pumping capacity was staying ahead of
>> greater-than-expected water flow, but a concrete barrier was taking longer
>> to build than expected. Grandey said the mine could be closed for as long as
>> six months, with Cameco losing up to $5 million in profit for every month
>> McArthur River is out of production.
>> 
>> Although flooding can be a problem for any underground mine, it is
>> particularly worrisome at McArthur River, because of production and
>> processing taking place primarily underground.
>> 
>> The main shaft plunges 685m, and Cameco is currently mining uranium-bearing
>> rock between the 530m and 640m levels. Underground processing was seen as a
>> way to minimise the mine's environmental impact. A grinding mill at the
>> lowest level of the mine has already been flooded. In its latest update,
>> Cameco said the critical area of the mine, 640m below the surface, contains
>> processing equipment and large pumps that would be lost if pumping capacity
>> does not keep up with the water coming in.
>> 
>> A concrete barrier has been poured, and is expected to take several weeks to
>> cure. In the meantime, the company will continue its efforts to ensure that
>> it stays ahead of the water, and protects the deeper, critical part of the
>> mine.
>> 
>> Mine personnel have improved the method of measuring water inflow and
>> determined that the flow rate is higher than previously estimated. However,
>> they have successfully added more pumping capacity. Water treatment
>> capacity, on the surface, has also been substantially increased and is
>> currently capable of matching the pumping capacity.
>> 
>> © Copyright Wilmington Group plc
>> 
>> 
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