Re: Emergency Doses Allowed

[David W Lee <lee_david_w@lanl.gov>]

Skip:

	Thank-you for your rapid reply.  But now that you have clarified that the
dose limits/guidelines for emergency exposure conditions in 10 CFR 835.1302
are TEDE doses, not merely whole-body external doses, what do you propose
be done to address Joyce's original point?  Since the amount of a
long-lived alpha emitter required to impart a CEDE of 25 or 50 rem is
minuscule and such an amount can on rare occasion be intaken in a Pu
nuclear facility as part of routine operations, not "emergency exposure
conditions," is it not then appropriate to consider revising the limits of
10 CFR 835.1302 upward in a manner that would somehow permit or recommend a
CEDE for Plutonium that is appropriate for an "emergency exposure
condition" rather than the present set of dose limit numbers, which since
they are as you say CEDE limits as well as external DE limits, appear to be
truly inappropriate in the case of long-lived alpha emitters?

	It appears that when DOE originally wrote 10 CFR 835 that DOE compiled the
10 CFR 835.1302 table of "Guidelines for Control of Emergency Exposures" as
if the dose limits listed were assumed to be strictly external DE limits.
It appears as if they did NOT consider placing numerical dose limits into
this table that accommodated the reality that you state that the dose
limits listed are actually TEDE limits, not simply external DE limits.  If
the numerical limits listed are actually TEDE limits, then this means that
a person could sustain all of his/her emergency dose via either CEDE or
external DE.  If the individual sustained all of the allowable TEDE by
strictly CEDE, then in the case of plutonium, the CEDE dose limit/guideline
value specified in the table should be much, much higher in recognition of
the fact that under emergency exposure conditions potentially involving the
inhalation of Pu, the intake of Pu would be much greater than just a the
few atoms it otherwise presently takes to impart a Pu-239 CEDE of 25 or 50
rem.  

	So under such TEDE/CEDE circumstances, in the case of plutonium, what do
you think would be a realistic CEDE value involving the intake of Pu under
"emergency exposure conditions"?

Best regards  David


At 03:16 PM 6/4/1998 -0500, you wrote:
>
>
>
>Based on some of the replies I have seen to this question regarding
>DOE requirements, I would offer some facts from 10 CFR 835.  The
>requirements for Planned Special Exposures are contained in Subpart C,
>835.204, while the requirements and/or guidelines are contained in
>Subpart N, 835.1302.  these are separate and distinct requirements and
>exposure in the one case is not intended to be counted in the other.
>
>As to questions of how either Planned Special Exposure or Emergency
>exposure affect future occupational dose, 835.204(f) states that the
>dose from planned special exposures is not to be considered in
>controlling future occupational dose of the individual under 835.202,
>but is to be included in records and reports required under this part.
>Subpart N-Accidents and Emergencies states that any employee who has
>exceeded occupational exposure limits specified in 835.202 and 835.205
>(skin dose) may be permitted to return to work in radiological areas
>during the current year provided that all of the following conditions
>are met: approvals from the contractor organization and the DOE field
>organization, counseling of the individual by Radiation Protection and
>medical personnel on the consequences of receiving additional
>exposure, and the employee agrees to return to radiological work.
>Subpart N likewise requires that all emergency exposures be recorded
>and reported.
>
>On the questions regarding whether you should use external exposure,
>CEDE or TEDE when determining exposure for planned special exposures
>and emergencies, all exposure within DOE is required to be reported in
>accordance with 835.203 which says that the TEDE during the year shall
>be determined by summing the effective dose equivalent from external
>exposures and the committed effective dose equivalent from intakes
>during the year.  Since both 835.204 and 835.1302 require recording
>and reporting of the individuals dose (to be entered into the
>individuals exposure records) and DOE uses TEDE to determine
>individual dose, the limits associated with these two sections of 10
>CFR 835 should be TEDE doses.
>
>Joyce Davis has a point since it won't take much of a plutonium uptake
>to exceed 25 rem TEDE.
>
>These are my thoughts on this question.
>
>Thanks for listening,
>
>Skip
>Alois.Singer @hq.doe.gov
>
>

DAVID W. LEE
Los Alamos National Laboratory
PO Box 1663, MS K483
Los Alamos, NM  87545
PH:  (505) 667-8085
FAX: (505) 667-9726
lee_david_w@lanl.gov