RE: Re[2]: Side of a volcano

[rkathren@tricity.wsu.edu (Ron L. Kathren)]

PLEASE NOTE:  ACTUAL MEASUREMENTS OF THE CONCENTRATION OF RADIOACTIVITY IN
THE MOUNT SAINT HELENS ASH WERE PUBLISHED IN SCIENCE IN THE PAPER BY SOLDAT
ET AL AND IN EARLIER WORK IN SCIENCE BY FRUCHTER ET AL.  THE MEASURED K-40
CONCENTRATIONS IN FRESH MOUNT SAINT HELEN'S ASH WERE 7.73 PICOCURIES PER
GRAM; THE MEASURED RADIUM-226 CONCENTRATION WAS 0.376 PICOCURIE PER GRAM.
THESE LEVELS WERE APPROXIMATELY THOSE OF THE SAME NUCLIDES IN THE SOIL IN
THE VICINITY OF MOUNT SAINT HELENS.  AGAIN I REFER RADSAFERS TO THE
PREVIOUSLY PUVBLISHED ARTICLES ON MOUNT SAINT HELENS, SPECIFICALLY SCIENCE
209:1116 (1980) AND 213:434 (1981).
RON KATHREN

 At 03:59 AM 8/6/98 -0500, Simon "M." Jerome wrote:
>Good morning.
>
>Surely the point is that the emission of material from Mount St Helens 
>was distributed throughout the 4 km³ of ash and as such, the 
>radioactivity was not concentrated at any one point. Given that, the 
>figures could be read as;
>
>K-40	555 kBq/m³
>Ra-226	27.8 kBq/m³
>
>This compares with the crustal average (data from the CRC Handbook of 
>Chemistry & Physics, 75th edition) of;
>
>K-40	~600 kBq/m³
>Ra-226	~30 kBq/m³
>
>Not a great difference.
>
>At a Nuclear site is that although the discharge levels may well be 
>lower, but the local concentration is somewhat higher.
>
>It would, of course, be interesting to know if the Radon-222 and it's 
>daughters rained out with the ash or escaped to the atmosphere. Either 
>way, there is an additional 52 TBq (oh, alright...1400 Curies) each of 
>Pb-210, Bi-210 and Po-210 around somewhere. 
>
>
>Simon Jerome
>National Physical Laboratory
>UK
>
>Email	simon.jerome@npl.co.uk
>Internet	http://www.npl.co.uk/
>
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