NukeWorker Forum
Reference, Questions and Help => Nuke Q&A => Lessons Learned => Topic started by: Gordon Freeman on Feb 11, 2005, 05:59
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Hi,
I am looking for a suitable coating/paint/sealant/film/fixatives for loose alpha contamination as part of a decommissioning project. The items are to be size reduced after the fixative has been applied. The fixatives primary purpose is the temporary fixing of the alpha contamination during cutting. The outline of the fixative's requirements are listed below. The identified constraints of application are as follows (in no specific order):
- It won't be exposed to natural light.
The coating will generally be applied in an environment where operators will wear protective suits so they won't be overly dextrous. Equipment such as a spray/fogger or brush would be ideal (compressed air application can be used in this application if necessary).
Due to the environment, operators need to try and keep quantities of the coating used to a minimum.
There is no specific cured coating thickness required as long as all the dust trapped by the coating remains trapped during and after cutting.
The coating is not really intended for long term use (days to weeks is envisaged but longer would be beneficial)
The coated surfaces will be dry when the coating is applied.
The application temperature is at room temperature with very little variation of this temperature.
Application would be made in a 2 hours time period and should include the ability to apply an overcoat in this time period if necessary.
Substrates to which the coating is to be applied to are mild and stainless steel, aluminium, Perspex and painted substrates (the paint types are unknown).
The items the coating is applied to (pipework, tanks, etc.) are to be cut up by cutting through the coating materials; cold cutting methods will be used to make the cuts i.e. nibblers, crimp & shear, band saw, etc. The coating needs to needs to 'withstand' the act of cutting and any vibrations associated with cutting i.e. remain in contact with the substrate throughout the cut and not peel away.
Exposure to sparks should be at a minimum. No significant increase in heat is expected.
Not expected to be exposed to acids, alkalis, sparks/flame, organics, (except perhaps a little lubricant to aid cutting but this will be minimised), or water.
The coating can be water or solvent based
No colour constraint but identification of coverage will be necessary, possibly a opaque colour so that the item beneath can just be made out and yet coverage can be identified would be the ideal.
It would be beneficial (but not essential) if the coating remained tacky to be able to trap any loose material that lands on the surface (as long as tackiness does not interfere with cutting efficiency).
Primarily the duration the coating has to be in place is only for the duration of the cutting but a coating that gives a long-term containment would be advantageous.
Provide removal of loose particulate matter from the items applied to if it is decided to strip the coating.
Anyone had good experience of use of any proprietary products (e.g's include ALARA 1146 or Spraylat strippable coatings) that they would recommend reviewing.
Any help is much appreciated.
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I have an idea that might work for you. I did a stretch in the Environmental abatement field. We were consultants on a tremendous amount of asbestos abatement jobs. The asbestos abatement companies used a spray on encapsulant that was thin white and paint-like. It was more like a white wash. It could be applied with your run of the mill airless paint sprayer. I recall that it locked down any remaining asbestos fibers. We would use a leaf blower in the room after the abatment was done and the encapsulant applied. We would then collect air samples. If the encapsulant was applied evenly all over the air samples always came back clean. Try contacting the local asbestos abatement contraactor/supplier in your area maybe they can help.
Hope the info helps
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one thing to remember in doing an analysis for coatings to be applied is that no matter what coating you use the coservative approach is to utilize engineering controls during the cutting operations post coating evolution. in other words; no matter how you coat the material, the cutting will have a deleterious effect on the coating and it's ability to contain the material coated. coating a material does not necessarily delete the necessity to have engineering controls in effect during the destructive phase of material handling, as per alara concerns.
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Thanks for the pointers, much appreciated.
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I have worked with some folks who have various coatings that can be applied either hard or tacky depending on your needs. I have used them for glovebox abatement as well as building demo. IM me and I'll give you a contact name.
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I've used a 3M spray glue on ra226 alpha contaminated surface~20kdpm/100cm2 that I had to size to fit into b-25 boxes.I sprayed ~2 feet above the surface as not to cause the accellerant to cause a significant problem.I was in a FFNP/p-100 hepa filter respirator on also.The B/Z airsample came back <.1DAC.Depending on how you are cutting you always have to contain the shavings as radwaste.The glue stayed tacky and this worked fine for me.
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This should work for ya! http://www.bartlettinc.com/sp.cfm?pageid=1760
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I've used a 3M spray glue on ra226 alpha contaminated surface~20kdpm/100cm2 that I had to size to fit into b-25 boxes.I sprayed ~2 feet above the surface as not to cause the accellerant to cause a significant problem.I was in a FFNP/p-100 hepa filter respirator on also.The B/Z airsample came back <.1DAC.Depending on how you are cutting you always have to contain the shavings as radwaste.The glue stayed tacky and this worked fine for me.
Hi,
Are you able to let me know which 3M spray glue you used as a fixative?
3M Spray Mount Artist's Adhesive 6065
3M Adhesive Remover Citrus Base 6040-6042
3M ReMount Repositionable Adhesive 6091
3M Photo Mount Spray Adhesive 6094
3M Vac-U-Mount Spray Adhesive 6096
3M Super 77 Multipurpose Spray Adhesive
Many thanks
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Gordon,
I made a similar post weeks ago. I have been doing extensive research on this since then. I can find no data on effectiveness. There are 2 popular products: Bartlett barrier paint (PBS) and Instacote by Master-Lee.
For a real basic fixative try: http://www.fogging.com
Send me an email at work and I'll email you the price comparison spreadsheet that I did: ray.mcginnis@boeing.com
Here is the link to my Nukeworker post on this subject:
http://www.nukeworker.com/forum/index.php?topic=5766.msg34275;topicseen
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not sure what your exact needs are but if your looking for a fixitive that will eliminate or reduce the amount of airborne during cutting operations on gloveboxes or piping or related items you might look at a company called encapsulation technologies ( www.fogging.com ) they use a system to encapsulate items such as those mentioned above and also have been used in D&D operations during clean up and decontamination of various hotcells ect ect. hope this helps ya
James