Re: Lead Caskets

["jjcohen" <jjcohen@PRODIGY.NET>]

Ted,

    I think this "rule of thumb" applies to gamma radiation in the >Mev range. For plutonium (the case in question, assuming Pu-239)) , the major concern would likely be alpha emission for which any thickness of lead, earth, or cardboard would be completely effective. There is also a weak gamma emission (~80Kev), for which I would guess the shielding thickness of Pb equivalent to 2 meters of dirt would likely be something less than 1 micron. How much less is the question, or more generally--- what would a lead lined casket  accomplish in the case of Pu contamination that the earth cover would not?    Jerry

  ----- Original Message ----- 

  From: Ted Rockwell 

  To: jjcohen ; radsafe@list.vanderbilt.edu 

  Sent: Saturday, September 18, 2004 12:23 PM

  Subject: RE: Lead Caskets





  Jerry:



  The old rule of thumb (rough) was: a foot of concrete = an inch of lead = two inches of iron.  Most earthen walls would be less dense than concrete--maybe as much as half as dense.  And this is for the most penetrating energy, which is about 2 MeV.  For higher or lower energies, lead is MUCH more effective than the lower Z elements.



  So, if you say 2 m of earth = 4 ft of concrete = 4 inches of lead.  To the extent that lower energies are present, the lead would be more effective.



  Ted Rockwell

    -----Original Message-----

    From: owner-radsafe@list.vanderbilt.edu [mailto:owner-radsafe@list.vanderbilt.edu]On Behalf Of jjcohen

    Sent: Friday, September 17, 2004 3:44 PM

    To: radsafe@list.vanderbilt.edu

    Subject: Lead Caskets





    Just out of curiosity-- what thickness of lead shielding would be equivalent to ~ 2 meters of earth cover for attenuating radiation emissions from plutonium contamination in a corpse???