table 2 appendix b

["Les Slaback, Health Physics" <SLABACK@micf.nist.gov>]

Question regarding dose basis for 10CFR20 Appendix B Table 2:
20.1302(b) and the preface to App. B very clearly state that the values
in Table 2 are based on 50 mrem.

But the notes relating to the calculational factor used to derive the Table 2
value from the Table 1 value are very clearly based on 100 mrem.  In the case
of submersion nuclides this factor include the factor of 50 (5000/100) and
4.38 (to account for different exposure times).

In the case of inhaled nuclides the factor also includes the difference in
inhalation rates and an age group adjustment (a factor of 2 for this).

But in both instances the basis for the adjustment is 100 mrem, despite the
declared basis of 50 mrem.

Separately, NRC talks about Table 2 being based on 50 mrem, except that it is
100 mrem for submersion nuclides.  The only basis I can see for this is that
they basically ignore the factor of 2 for age adjustment and apply it to
making the dose basis 50 mrem instead of 100 mrem.

The fundamental question is:  what is the basis for treating the Table 2 values
differently for submersion nuclides compared to others in terms of the
projected public dose?

SLABACK@MICF.NIST.GOV
   ...a little risk, like a bit of spice, adds flavor to life