Release of I-131 Patients

["Andrew Welsh" <WELSHA@kbpnfs01.eskom.co.za>]

Hi everyone

I'm a radiochemist at a nuclear power plant in South Africa, and am 
involved in our environmental monitoring programme.

This topic of releasing I-131 patients interests me as last year on 
two occasions we detected significant levels of I-131 in the sludge 
from the sewage treatment plant a few kilometres away.  As it was 
very unlikely, for various reasons, to have originated from our 
nuclear plant, we investigated other potential sources of I-131.  
With the help of the government Dep. of Health, two patients were 
traced, who live in the nearby village, who had received I-131 about 
a week and a half before each of the incidents.  The levels in the 
sludge were about 1500 Bq/kg!  In both cases, the succeeding samples 
had reduced I-131 activity corresponding very well to I-131's 
half-life.

As I am not a radiologist, I would like to know a bit more about what 
sort of doses patients typically receive, and how soon they are 
released from hospital.  (The information we have indicated that they 
received approximately 220MBq.)

Regards

Andrew Welsh
Koeberg Nuclear Power Station
Cape Town
South Africa