Re: NRC Event Report

["Glenn marshall" <gmarshall@duratekinc.com>]

I was hoping the licensee would respond to Bill's question.  Perhaps they don't subscribe and therefore didn't see the question, or maybe they're still investigating and don't want to put out any more information right now than is absolutely necessary (I can relate).  



They found 800 dpm/100 cm^2 (within DOT and 1.86 limits) over an area of about 10 x 12 inches.  So there were maybe 6000 dpm of tritium present on the floor.  Tritium gas doesn't usually settle out as surface contamination so we can assume it was vapor.  I'm NOT advocating the use of a particulate filter to remove tritium; efficiency is assumed to be zero and is in reality probably pretty close to that.  Using a filtered vacuum cleaner on high levels of tritium can ruin your day.



But let's assume the worst case, that they used an old Hoover with a hole in the bag.  Inhalation ALI is 80 mCi.  That 6000 dpm, if it all went airborne and was all inhaled, works out to about 3 E-8 ALI.  



While no harm was done, I'd be interested in knowing the thought process.



Glenn



>>> William V Lipton <liptonw@DTEENERGY.COM> 01/30/03 10:06AM >>>



I have one question regarding the licensee response.  They suspect that

the contamination is tritium, and found contaminated carpeting in the

delivery vehicle.  Why did they decon by vacuuming?  No details are

provided, but I assume that they used a commercial vacuum cleaner.  This

would have very efficiently transformed surface contamination into

airborne contamination, since the vacuum cleaner filter would not retain

the tritiated vapor.  The only thing I can think of is that it was

vacuumed through a bubbler or drying agent (e.g. silica gel).  This

would work IFF the tritium is present as water vapor.



Would the licensee be willing to provide more details on this?



| "IPL had the delivery truck return to IPL, & they found a small area

of      |

| contamination, about 12 X 10 inches, on the carpet, where the package

was    |

| located, of about 800 dpm/wipe. After vacuuming, they got nothing.

About 11  |

| other wipes in the truck were negative. They checked the driver's

gloves-    |

| there's no removable contamination. All wipes @ IPL's Shipping Dept

were     |

| negative. 

| "Note: Assuming that the contamination is H-3, the dose consequences

of      |

| 100,000 dpm/wipe are approximately equivalent to the dose consequences

of    |

| 2.5 dpm/wipe of

Cs-137."                                                     |

+------------------------------------------------------------------------------+





************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/ 





************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/