RADSAFE digest 1554 -Reply

[Colleen Casey <CCC@nrc.gov>]

TO:  Richard Wu and other interested parties

FROM:  Colleen C. Casey, ccc@nrc.gov, Nuclear Materials Licensing Reviewer

RE:  I-131 Bioassay Procedure Requirement

FYI-
The issue concerning bioassay requirements for encapsulated iodine-131 was resolved
many years ago.  Please see the "Statements of Consideration (SOC)" published in
the middle of Regulatory Guide 10.8, Rev. 2, August 1987.  The SOC included
responses to comments made during the last complete revision of 10 CFR Part 35 and
were published in the final rule dated October 16, 1986.

On page S-20, third column, in the middle, a commenter stated,"It is not necessary to
measure the thyroid burden of personnel who administer encapsulated iodine-131."

The NRC's response follows: "The NRC disagrees.  It has been observed
("Contamination from Therapeutic I-131 Capsules," by D.R. Shearer, et al., Health
Physics v49 p81, July 1985) that individuals who handle encapsulated iodine-131 may
be exposed to levels of surface contamination for which thyroid monitoring is
indicated.  No change has been made."

The reference to "No change has been made" means that the regulation was not
changed from the draft version when the final rule was published, as a result of the
comment.

Single copies of Regulatory Guide 10.8, Rev. 2 may be obtained, free, from any
regional NRC office.