Re: SFP Locking Mechanisms

[Gv1@aol.com]

I haven't really seen anything more than a picture, since our fuel pool is so 
new and clean, but I have seen a picture of an example where a high rad 
object was tied off to the fuel pool railing.  A metal box would lock to the 
rail and cover the point on the railing where the item was tied off.  
Trefoils and HRA wording would be on the box so that it would be conspicuous 
to anyone that might approach.  The box would prevent access to the rope for 
about 1 foot in every direction.  This arrangement seems to meet the 
regulatory intent for a locked high radiation area such that a red flashing 
would not be needed.  

In the example I've seen, a person could still circumvent the controls if 
they really made a concious decision to.  While this might meet the intent 
for locked high radiation areas, I'm sure additional discussions would ensue 
if it were to be used for a very high radiation area with respect to the 
"undetected circumvention" clause in the reg guide and whether the "lockable 
enclosure" provided the same level of rigor as a locked door.  I believe the 
reg guide does recognize that there are some difficulties that might be 
encountered in trying to control every conceivable type of area.

Glen Vickers
Nuclear Power HP
glen.vickers@ucm.com
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