Re: Non-power reactor waste questions

["Wesley M. Dunn" <WDUNN@brc1.tdh.texas.gov>]

Speaking as the Regulator (in Texas, at least), I think I might be
able to give a reasonable answer:

For hospitals:

An estimated 80% of all use is Tc-99m (6 hour half-life).  The
longest half-life typically used is I-131 (8 days).  Most hospitals
in Texas with decay programs get by quite well with a 10 day cap.
However, the use of Sr-89 (57 days) is starting to cause problems for
multiple reasons (e.g., strong beta emitter and long half-life).

For Universities:

This is a slightly different matter.  P-32 (14 days) and S-35 (87
days) are the major research 'topes for tracer studies.  I-125
(60 days) use has dropped significantly in the past 15 years, but is
stil a sizable fraction.

In Texas, we authorize Decay In Storage commensurate to the
licensee's waste program.  If you can deal with 3 year storage for S-
35, we grant it.  If you can't, we don't.

Wes


> Date: Mon, 9 Jan 95 19:11:55 -0600
> From: SMITHCH01@delphi.com
> Subject: Non-power reactor waste questions
>
> These questions are directed toward universtiy and hospital RSO's.
> 1. What is the maximum half life for isotopes managed by decay in storage
> allowed by your licensing agency?
> 2. Excluding H3 and C14, what half life for isotopes managed by decay in
> storage would encompass a majority of wastes generated at your facility?
>