[ RadSafe ] Robots scour sea for atomic wasteSubmarines search for radioactive material dumped off the Scottish coast in the 1980s

[Steven Dapra]

May 27

         Thank you, Professor Cohen for explaining this.

Steven Dapra


At 06:05 PM 5/27/08 -0400, Bernard L. Cohen wrote:
>    According to my paper on "Hazards from Plutonium Toxicity" (Health 
> Physics 32:359-379;1977) LD-50 for ingesting reactor plutonium in soluble 
> form is 0.7 grams, and in insoluble form is 2.0 grams. If the material is 
> not dissolved in the ocean water, it is presumably insoluble. So 
> presumably, a "speck" is something more than 2.0 grams. Pure Pu-239 is 
> seven times less dangerous than reactor plutonium (because of the Pu-238 
> in the latter) so a "speck" of Pu-239 would weigh about 14 grams, about 
> one cubic centimeter in volume..
>    LD-50 for ingestion of some other commonly available materials are: 
> selenium oxide (used extensively in electronic devices) -0.3 grams, 
> mercury dichloride (formerly widely used for soaking fingers or toes to 
> draw out infections) - 0.8 grams, and caffeine (which all of us 
> frequently ingest) - 14 grams.
>    Basically, plutonium is dangerous only if inhaled as a very fine dust..
>
>
>Steven Dapra wrote:
>>May 25
>>
>>         This article was written by the "science editor."  I didn't know 
>> "one speck" of plutonium was "capable" of killing me if I swallowed 
>> it.  Goodness.  Life is full of surprises, isn't it?  Is a speck one of 
>> the International Units?  How many specks are there in a gram, or is it 
>> vice versa?
>>
>>Steven Dapra
>>
>>
>>
>>At 09:54 AM 5/25/08 +0100, Fred Dawson wrote:
>>>Guardian Reports:-
>>>
>>>Robot submarines are to be used to sweep particles of plutonium and other
>>>radioactive materials from the seabed near one of Britain's biggest nuclear
>>>plants in one of the most delicate clean-up operations ever in this country.
>>>
>>>Each submersible will be fitted with a Geiger counter and will crisscross
>>>the sea floor to pinpoint every deadly speck close to Dounreay on Scotland's
>>>north coast before lifting each particle and returning it to land for safe
>>>storage.
>>>
>>>Two kilometres of beach outside the Dounreay nuclear plant have been closed
>>>since 1983, and fishing banned, when it was found old fuel rod fragments
>>>were being accidentally pumped into the sea. The cause was traced and
>>>corrected but particles - including plutonium specks, each capable of
>>>killing a person if swallowed - are still being washed on to this bleakly
>>>beautiful stretch of sand and cliff on mainland Britain's northern edge.
>>>
>>>Full report
>>>
>>>http://www.guardian.co.uk/environment/2008/may/25/pollution.conservation
>>>
>>>fwp_dawson at hotmail.com
>
>--
>Bernard L. Cohen
>Physics Dept., University of Pittsburgh
>Pittsburgh, PA 15260
>Tel: (412)624-9245  Fax: (412)624-9163
>e-mail: blc at pitt.edu  web site: http://www.phyast.pitt.edu/~blc