German spent fuel

["Roy A. Parker" <70472.711@compuserve.com>]

Eric,
 
I can  not provide  any insight  into the  German  spent  fuel  shipping
problems, but  I think  there is  a need  to clarify some misconceptions
concerning permissible  surface contamination  limits on  transportation
packages.
 
The IAEA  and other  various international regulations do state that the
maximum non-fixed  contamination beta,  gamma  and  low  toxicity  alpha
emitters  on  the  external  surfaces  of  a  package  must  not  exceed
4 Bq/sq cm averaged  over 300 sq cm.   The corresponding U.S. regulation
49 CFR 173.443 Table 11  states that the maximum non-fixed contamination
beta, gamma  and low toxicity alpha emitters on the external surfaces of
a package  must not exceed 0.4 Bq/sq cm over 300 sq cm.  It appears that
the U.S.  regulations are  a factor  of 10  lower than the international
standards.  In fact, they are not; and they mean the same thing.
 
The international  standards assumes that one will apply the appropriate
efficiency correction  factors for  energy, geometry and removability of
the  surface  contamination  when  counting  wipe  samples.    The  U.S.
regulation assumes  that  one  will  apply  the  appropriate  efficiency
correction for  energy and  geometry; but assumes a removable efficiency
of  10 percent.     The  U.S.  regulation  further  goes  on  to  state,
49 CFR 173.443(a)(2),  that   if  the   removable  efficiency   can   be
established, then  the non-fixed  contamination limit  on the surface of
the package  may be a factor of 10 higher than Table 11, which makes the
regulation equivalent to the IAEA international standard.
 
The U.S. regulation goes on further to provide in 49 CFR 173.443(b) that
for exclusive  use transport  the removable (non-fixed) contamination on
any surface  of the package during transport may not exceed 10 times the
levels in Table 11 with the proviso that the contamination levels at the
beginning of  transport did  not exceed  the Table  11 values.  The IAEA
Regulations for the Safe Transport of Radioactive Material do not appear
to contain a similar provision.
 
Roy A. Parker, Ph.D.
E-Mail: 70472.711@compuserve.com
Tel: 504-924-1473
Fax: 504-924-4269