Permanent Shielding -Reply

[Lonny Eckert <LLE@nrc.gov>]

Cliff,

I have never seen "permanent" shielding in a
drywell anywhere and I doubt that your
engineering staff would permit such an
installation on other than a very limited basis.  It
might impact the ability of your containment
spray system to carry out its intended function. 
Don't forget fire protection if for some reason
you wish to use wooden planking rather than
metal planking.  Of course, it must be
seismically qualified if it is a permanent
installation.

Oyster Creek has installed permanent
scaffolding in their drywell.  This has permitted
them to quickly install their shielding in the
beginning of their outages.  FYI:  they have
placed an average of about 80K-100K pounds
of lead blankets in their small drywell the past
several outages.  Oyster Creek has some
unique considerations in that they have but one
hatch into their drywell while I imagine that you
have three.  This forces them to prestage the
shielding packages and to schedule their
shielding crews.  I think they would be your best
bet as a contact in Region I and are within
driving distance from LGS.  Good luck.


Lonny Eckert
NRC Region I
LLE@NRC.GOV