RE: Plasma Torch Cutting

["Larry Boing" <lboing@ANL.GOV>]

We have done some work with plasma arc cutting in our decommissioning here.

You need to really plan ahead and do some aggressive monitoring to stay on

top of the situation.  Just like anything in D&D characterization is

critical.  When working in any underwater environment you can have

conductivity issues with using the plasma arc systems.  In pool settings,

you also need to have a good means of collecting the small bee-bees formed

when cutting.  Yankee Rowe and several other NPP did a lot of plasma cutting

and might serve as good points of contact.  Some of the plasma cutting

problems in the past have lead some NPP to go more with abrasive jet cutting

for RPV internals cutting as I understand it.



Larry 



Lawrence E. Boing

Argonne National Laboratory

Nuclear Engrg Division, Decommissioning Program

9700 South Cass Avenue, Bldg 362

Argonne, IL   60439    

 

Phone 630.252.6729

Fax     630.252.5287

lboing@anl.gov

 

www.td.anl.gov/D&D/

www.orau.gov/ddsc/

 



-----Original Message-----

From: owner-radsafe@list.vanderbilt.edu

[mailto:owner-radsafe@list.vanderbilt.edu] On Behalf Of NIXON, Grant

(Kanata)

Sent: Wednesday, August 13, 2003 3:45 PM

To: 'Dave Biela'; radsafe@list.vanderbilt.edu

Subject: RE: Plasma Torch Cutting





Dear Dave,



(1) Chemistry: You are non-specific on the type of contamination on the

surface. But this item is important in order to understand the possible

chemical reactions that can take place.



As an example, C-14 contamination in an oxygen-rich environment (air) (+

heat) would prove a much different sort of radiological hazard (e.g., via CO

and CO2 formation) than would, say, Cs-137 contamination.



(2) The physics describing the release of contaminants or other particles

adhered to surfaces due to heating is a fairly well-known subject (adhesion

w.r.t. volatiles). This is a surface physics item that ought to be familiar

to semiconductor and optics people.



(3) The most significant and typical contributions may be due to the action

of air currents on loose particulate contamination.



The radiological protection issues can be better addressed by the experts

once you obtain and provide more information, particularly item (1).



Best regards,



Grant





-----Original Message-----

From: Dave Biela [mailto:Dave.Biela@wvnsco.com]

Sent: Wednesday, August 13, 2003 3:51 PM

To: radsafe@list.vanderbilt.edu

Subject: Plasma Torch Cutting





We are doing some work using a plasma cutter on contaminated stainless

steel and would like to discuss lessons learned with others who have

used this method.



One of the main questions is:  What were your ratios of airborne

contamination concentrations in the work area to contamination levels on

the cut surfaces?



If your interested in a discussion, contact me directly at

dave.biela@wvnsco.com  or

716-942-4423



Thanks

Dave Biela

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