Re: Steam Generator Replacement Calculations

[Gv1@aol.com]

A couple of quick thoughts...

These S/G's are probably coming out of a hole cut in the side of containment. 
 This will be the effluent pathway.

When the S/G's are being lifted, the only semi-accessible source term would 
be dropping the S/G on the covering over the reactor cavity.  Possibly assume 
some uCi/cm^2 or use historical data and multiply by the entire surface area 
of the cavity.  You could assume the entire amount becomes airborne and 
leaves containment through the opening.  You'd obviously assume the roll-up 
door covering the hole in containment and the ventilation drawing a vacuum on 
containment fails also.

As far as realistic release rates in ft^/min you could call a couple of 
plants and talk to their effluent people about the rates they measured for 
their containment openings.  Try Byron, Braidwood, and Farley for some recent 
replacement data.

I never saw the 50.59 documentation for this scenario, but after watching the 
replacement outage at Braidwood, I'd say this is the most likely scenario.  
It really is neet to see how they move a 400 ton object around...

Glen Vickers
Braidwood Nuclear Station
glen.vickers@exeloncorp.com