Re: Dispersal of Spent Fuel -Reply -Reply

[Todd Jackson <TJJ@nrc.gov>]

In partial response to John Sadler,

I believe spent fuel pool racks are designed to avoid the possiblity of criticality under most
conditions, including cold water.  In fact the water serves as shielding and for decay heat
removal.  I would think criticality would only be a concern if bundles were somehow configured
outside of the racks, kind of piled together (rather a major and intentional undertaking) or
through some other very abnormal occurrence.  Not being a NucE experienced in rack
design, I'm not certain criticality could not occur but it would seem a strange design basis to
allow it to be possible.

Was't the original post for this thread more related to an explosive device blowing up a bundle
or something?  Very different scenario from what is encountered during power plant
operations.

Todd Jackson 
tjj@nrc.gov
Personal opinions only, not NRC etc....