Re: Concrete Demolition

[mail15077@pop.net]

Dear Kurt;

I would suggest the following measures:

1)  Buy herculite or gryfolen (or some other heavy plastic) and build a 
containment tent around the areas you want to jackhammer up.  Make sure that 
the tent is fairly well sealed (it doesn't necessarily have to be airtight).

2)  Use HEPA filtered exhausts to pull a negative-pressure on the tent.  We 
usually size to get about 10 volumes of air-change per hour.  You basically 
want there to be negative pressure on the tent so that any dust or debris is 
pulled into the HEPA filter.

3)  Additionally, keep a HEPA vacuum hose near the point of attack on the 
concrete.  This will pull more debris into a filtered airstream.

4)  Sometimes it helps to lightly spray the surface with DI water.  Keeps the 
dust down.

5)  Ensure that you take a BZA inside the tent, and that you monitor the 
exhaust streams of your HEPA exhausts.  Depending upon your situation, the 
exhausts of the HEPAs may require NESHAPS evaluation (primarily if they are 
exhausting directly to the outside, or if they are exhausting into an area that 
is not otherwise ventilated).  Check with your environmental folks on this 
point.

6)  Make sure your workers are respiratory qualified and that you are running 
periodic bioassays.

This is a quick overview, but it generally covers the basics.

Jim Barnes, CHP
RSO
Rocketdyne Division; Rockwell Aerospace
========================================
> Does anybody in radsafe have experience controlling airborne contamination
> generated by an electric jack hammer?  We're planning to use a "Bosch
> electric breaker hammer" to decontaminate about 15 sq. ft. of Cs-137 and
> Sr-90 contaminated concrete inside a building.  Based on core sample results
> we're going to remove the top  1" from a 12" thick slab.  Of course we'll be
> using respitory protection, but we don't want spread contamination to the
> adjacent lesser contaminated areas so we want some engineered control for
> the dust. I really don't have time to experiment on clean concrete with
> various size HEPA vacs.  Any practical advice is appreciated.  Thanks in
> advance.
> 
> 
> **********************************************
>   Kurt R. Geber
>   Lockheed Martin Energy Research Corp.
>   Oak Ridge National Laboratory
>   P.O. Box 2008
>   Oak Ridge, TN  37831-6160
> 
>   Internet:   kg1@ornl.gov
>   Phone:      423-574-0929
>   Fax:        423-241-2779
>   
> 
>