Outside CA's and suspension

[Weasel]

I'm hoping someone can help me out with this.  I work at Hanford, part of the transuranic waste retrieval that was buried on site.  We started out in a trench with relatively perfect 55 gallon drums, and burial boxes.  Basically we dig up these old trenches, survey the drums, check the integrity, then transport them a short distance to our process area...all outside.  The problem is, the older the drums, the worse the integrity is getting on these things (obviously)  We recently ran into some contamination and posted a few modules CA.  It was then discussed and debated throughout the radcon world as to how we are going to handle these things, given our conditions (weather)  It was decided that when performing work in these CA's, radcon would post an exclusion area 30 feet away from the CA boundary and run airsampling in a 360 degree circumference.  Some number puncher came up with this 30 foot exclusion distance, given wind speeds that don't exceed 11 mph.  I don't believe this is sufficient.  The other day absorbent was being dumped into a burial box that was being loaded with bagged up drums, which had accumulated moisture inside the bags.  In the event they leaked for any reason, the absorbent would isolate the problem, bear in mind these boxes are then sealed, and later re-opened inside a greenhouse.  While these guys were dumping this "kitty litter" into the box it created a talcum powdery dust.  As I watched, this dust passed completely beyond our exclusion area, and up to 30-40 ft past it.  The problem I have, is that I don't believe contamination is less likely to do the same thing.  I was wondering if anyone works in a similar environment, and if you do, is there an equation to plug in suspension factors with any given wind speed.   Example: Something that tells me, in 5 mph Pu239 will travel "X" ft over terrain......It would help me immensely, and would be greatly appreciated with any input on this.

Thanks!   

[Rennhack]

The owner of "HASP", a guy named Cliff... used to do those calculations.  He said the calc was in the NRC regs some where.

You cold try to track him down.  HASP is based out of Oak Ridge.

[SloGlo]

your suspension factors are going to be dictated by the media involved. 

[Weasel]

Rennhack,

     It would be greately appreciated if you could look up this Cliff and relay his telelphone number to me.  I would appreciate it immensely.  There's been quite a few things going on lately, and quite a few rumors of layoffs, so my head has been in the clouds.  Again it would be appreciated if you could supply me with this information.  weaselmstr@charter.net

[Weasel]

I've searched long and hard to no avail.  Short of reading the NRC regs front to back, i'm not sure what to do.  I haven't tried to search for that individual you spoke of previously, not really sure how to contact him.  Does anyone have experience with this sort of situation, simply put outside ara's and ca's with wind gusts up to 25mph regularly.  Any insight?

The Weeze

[atomicarcheologist]

Have you checked in the Health PHysics and Radiological Handbook for this type of equation?  If you can't locate it there, I would do searches iin Industrial Hygiene reference material.  I would be more concerned with the physical form of the material than the isotope.  Metallic shavings will not go airborne in 25 MPH,  water will evaporate more quickly as long as temperature is stable, i.e. the evaporation rate is greater in a 25 MPH breeze at 45 degrees Farenheit than in a 2 MPH one.  However, at 95 degrees, the evaporative rate is much greater.  Dry material in small micron sizes maybe an airborne problem, however since you are adding absorbent material, this would not appear to be a concern.

[Beta_effect]

This might help:

http://www.hpa.org.uk/radiation/publications/w_series_reports/2002/nrpb_w1.pdf

Also if you can get a hold of RASCAL (NRC atmospheric dispersion model), the field measurement to dose model will allow you to calculate dose for any nuclide/resuspension factor as long as you know the surface contamination level. The simplest method would just to run some additional air samplers at various distances downwind (including beyond the exclusion zone) to see if a problem exists. Soil sampling beyond the exclusion zone might be interesting also. Why calculate something you can measure? Well, I guess we know why management might not go for that ($)...hope this helps!

[Drakus]

Why not use another material to cause the material ,that you are using, to clump, stick together in a drum shape or become more water like?

[Weasel]

Not sure what you mean Drakus, and as far as what you said Beta, you are completely correct....$$.  All of this alpha contamination, with a few exceptions, is fire waste.  Very flighty stuff, there's really no way of measuring this stuff without running about 100 airsamplers every time we retrieve (due to the wind direction constantly shifting) I was just looking for something like an equation that I could take to my bosses and say......SEE!!

The Weeze   

[atomicarcheologist]

That's what I thought you wanted and that's why I referenced you to IH material.  Check out this url and let me know if this will work for you.

http://www.rimbach.com/scripts/Article/PEN/Number.idc?Number=81

[Weasel]

That's really close to what I'm looking for Atomic, just not sure if I can sell it.  I'll no doubt print it out and show it off to the uppers, but I think their response will be that the equation is for already known contaminates in air, and that's the problem, we don't due to the wind shiftage. There's really no way to get a represenative sample.  But it is definately worth a try, Thanks!

The Weeze

[atomicarcheologist]

Let me know if you need assistance with the math.  What amount are you using as your trigger for alarm?

[alphadude]

there are so many variables in this situation that no model would be "canned" off the shelf.  the only answer to it is to sample it and what you have is what you get.  If you see a visible plume report it to your supervisor and get it documented. use the system to work for you.  the respirable fraction of 3-7 micron would have to be measured to make sense of this.

while all these answers are considerate, they seem to muddy the water.

[Weasel]

The entire situation is muddy, but I still appreciate the help.  As I had guessed the math didn't fly, considering it was a chemical equation.  Still working on it though.

[wlrun3@aol.com]

bevelacqua...basic health physics...page 356 ...particulate dispersion...pasquill atmosperic stability categories...

[atomicarcheologist]

The entire situation is muddy, but I still appreciate the help.  As I had guessed the math didn't fly, considering it was a chemical equation.  Still working on it though.

I thought Pu239 was a chemical, albeit isotopic. 

[alphadude]

the chemical would be the oxide of Pu- its elemental watson!