Re: Dedicated therapy room

["David Whitfill" <DWhitfil@kdhe.state.ks.us>]

This is consistent with NRC Regulatory Guide 8.23 (Radiation Safety Surveys
at Medical Institutions, Rev 1, 1/81) Table 2 values for Recommended Action
Levels for Removable Surface Contamination in Medical Institutions (page
8):

Unrestricted areas- beta or x-ray emitters = 220 dpm/100cm^2
Restricted areas- beta or x-ray emitters 2200 dpm/100cm^2

If low risk beta or x-ray emitters (such as C-14, H-3, S-35 or Tc-99m) the
values are multiplied by ten.
For fixed contamination levels, the Table 2 values are multiplied by five
(page 3).

Comments about the thread thus far:

The guide is dated, but to say it is not scientifically based seems
premature given the 34 references that are listed. It probably should be
reevaluated and brought up to date. Surface contamination control is an
ALARA issue, and if you can show by survey and subsequent dose projections
(or actual bioassay results) that the CEDE to your staff is a negligible
component of the TEDE, then you should consider negotiating a license
amendment with the NRC or Agreement State and propose new limits. I would
suggest that if your argument is strong, it may be worth an article
(perhaps for HPS's Operational Radiation Safety magazine?).




"Jacobus, John (OD)" <JJacobus@exchange.nih.gov>@romulus.ehs.uiuc.edu on
01/14/2000 07:27:32 AM

Please respond to radsafe@romulus.ehs.uiuc.edu

Sent by:  radsafe@romulus.ehs.uiuc.edu


To:   Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
cc:

Subject:  Dedicated therapy room


Rather than getting involved with the esoteric argument on the scientific
validity of decontamination limits, I offer the following information.  Our
institute has an amendment to our NRC license that permitted us to
decontaminate
to 2000 dpm/100 cm^2 between I-131 therapy patients.  If the room was to be
released to a non-therapy patient, contamination would have to be less than
200
dpm/100 cm^2.  This significantly reduces the time needed to prepare for
the
next patient.

-- John

John Jacobus, MS
Health Physicist
National Institutes of Health
Radiation Safety Branch, Building 21
21 Wilson Drive, MSC 6780
Bethesda, MD  20892-6780
Phone: 301-496-5774      Fax: 301-496-3544
jjacobus@exchange.nih.gov (W)
jenday@ix.netcom.com (H)
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