Re: ALARA or Not?

[Lester.Slaback@nist.gov]

>     The other staff members feel that if it costs $30 per respirator 
>     (including replacing cartridges, washing, ultimate replacement, etc.) 
>     that the cost of CEDE avoided should be considered in determining 
>     whether respiratory protection is required; even if there is NO 
>     significant external exposure concern.  These individuals believe 
>     that, for example, based on an assumed $1000 per man rem, respiratory 
>     protection is only warranted if it keeps someone from receiving 30 
>     millirem (both groups agree that the overall TEDE must be kept ALARA 
>     in cases with significant external exposure).  

*** Not only should the cost of the respirators be included but also an
appropriate fraction of the total costs of the respiratory protection
program, which is likely to be far greater.

>     Section 20.1702
>     
>     When it is not practicable to apply process or other engineering 
>     controls to control the concentrations of radioactive material in air 
>     to values below those that define an airborne radioactivity area, the 
>     licensee shall, consistent with maintaining the total effective dose 
>     equivalent ALARA, increase monitoring and limit intakes by one or more 
>     of the following means
>     
>     (a) Control of access;
>     
>     (b) Limitation of exposure times;
>     
>     (c) Use of respiratory protection equipment; or
>     
>     (d) Other controls.
>     
>     Does this imply that it is not ALARA to allow an individual to work in 
>     an area where the airborne concentration exceeds 1 DAC or the weekly 
>     exposure would exceed 12 DAC-hours per week (the definition of an 
>     airborne area)?

*** This rule seems very clear, particularly in the overall context of the
Part 20 revision where internal and external exposures are to be treated
equally. Resp. equip. is only one of 4 choices here, and (d) in fact opens
the issue to any method you can think of.  I do not read this as a mandate
to use respirators.

If a similar section existed for external exposure (with (c) changed to
something appropriate like shielding) would you read it as mandating the
(c) option?  The pre-1994 practices that mandated resp. protection were
supposed to have been discarded under the the revised  rules.

I would also make another observation: Even for persons who have been
medically  qualified the respiratory stress of using a respirator (or the
ergonomic stress of a supplied air system) would seem to be excessive
compared to the incremental risk of mrem level internal exposures.
-- 
the above are the personal musing of the author,
and do not represent any past, current, or future
position of NIST, the U.S. Government, or anyone else
who might think that they are in a position of authority.
NBSR Health Physics
NIST
Gaithersburg, MD 20899
301 975-5810
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Lester.Slaback@nist.gov
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