[ RadSafe ] Fukushima beta radiation burns

[Cary Renquist]

Just saw this:
*******************
NEI Nuclear Notes: The Japanese Workers <http://neinuclearnotes.blogspot.com/2011/03/japanese-workers.html>

The International Atomic Energy Agency (IAEA) said the three were contract workers laying cables in the turbine hall. Two of them were found to have radioactivity on their feet and legs. JAIF said they were exposed to more than 170 millisieverts (mSv).

The workers were washed in an attempt to remove radioactivity, but since there was a possibility of beta-ray burning of the skin, the two were taken to the Fukushima University Hospital for examination and then transferred to Japan's National Institute of Radiological Sciences for further examination. They are expected to be monitored for around four days.

It is thought that the workers ignored their dosimeters' alarms believing them to be false and continued working with their feet in contaminated water.

According to JAIF, the level of radioactive fission products in the water was about 3.9 million bequerels per cubic centimeter or 10,000 times higher than the reactor water used in the course of normal operations.
****************

They are holding them for several days to make sure that there aren't any skin dose issues from the observed contamination.

So, ~100 uCi/ml in the water...  (non-specified nuclides)
With a quick varskin-3 calc, 100 uCi (3.7 MBq) of I-131 over a 10 cm^2, 0.1 cm deep cylinder gives ~12 rad/h (0.12 Gy/h) skin dose.
(that would be 1 ml of water spread to a depth of 0.1 cm)

---
Cary Renquist
cary.renquist at ezag.com


-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Larry Addis
Sent: Friday, 25 March 2011 12:25
To: 'The International Radiation Protection (Health Physics) Mailing List'
Subject: Re: [ RadSafe ] Fukushima beta radiation burns

I was curious as to how the dose to the skin was diagnosed as "beta burns".
Do we think multiple dosimetry, as in extremity dosimetry was being used. 

I frequently required eleven individual dosimeters for jobs that met the
expected exposure parameters. But if that were the case here, and known or
unknown levels were suspect in water, high boots or waders would have been
required at a minimum. 

I've put workers in knee deep water before, but had them adequately attired
for the job.

I look forward to eventually getting good information from this event
overall so we can come to a better understanding of it.

LA 

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Cary Renquist
Sent: Friday, March 25, 2011 1:28 PM
To: The International Radiation Protection (Health Physics) MailingList
Subject: Re: [ RadSafe ] Fukushima beta radiation burns


Doesn't it take a while for even erythema to appear?
I know that Boric Acid isn't exactly the nastiest chemical out there, but
could it have caused skin irritation if it was in the water?
Or perhaps, the media is wrong?  I know, impossible!

---
Cary Renquist
cary.renquist at ezag.com

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Strickert, Rick
Sent: Thursday, 24 March 2011 13:51
To: The International Radiation Protection (Health Physics) Mailing List
Subject: [ RadSafe ] Fukushima beta radiation burns

Below are a couple of links on reports that three workers at the Fukushima
No. 3 reactor got beta-radiation burns on their feet when they were laying
electrical cables while standing in radioactively-contaminated water.  One
report stated: "TEPCO said radioactive water may have seeped through the
workers' radiation protective gear, causing radioactive materials in the
water to stick to their skin."  

The workers also received radiation doses of 17 to 18 rem while working from
10 AM to 12:10 PM (suggesting a 1.2 - 1.3 rem/h average dose rate).  It's
not clear whether the workers were standing in water the entire 14 hours.

Can one estimate (or WAG) the solution concentrations of beta-emitters
(Ci/L) that would have to be in the water for the workers to get radiation
burns from the water that seeped through the workers' radiation protective
gear (e.g. Tyvex booties over work shoes?)?  

http://e.nikkei.com/e/fr/tnks/Nni20110324D24JF855.htm 
http://calgary.ctv.ca/servlet/an/local/CTVNews/20110324/japan-radiation-tapw
ater-110324/20110324/?hub=CalgaryHome 


Rick Strickert
Austin, TX
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