United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 390: During 1993, there may be radiation workers

transiting between licensees that have, and have not,

implemented the revised Part 20. (a) In the case of a

worker whose dose was monitored earlier in the year at a

licensee that has implemented the revised Part 20 and is

now in processing at a licensee that has not implemented

the revised Part 20: (1) Should "whole body dose" be taken

as the "total effective dose equivalent" (TEDE) or as the

"deep dose equivalent" (DDE) recorded by the previous

licensee? (2) If the individual has received dose in

excess of an "old" Part 20 limit for the current quarter,

but less than the respective revised Part 20 limit for the

year (e.g., shallow dose equivalent to an extremity of 20

rems for both the current quarter and year to date), is the

individual unavailable for any further exposure in that

dose category for the remainder of the quarter? (3) If the

individual has received dose in excess of the "implied

annual limit" of the "old" Part 20, but less than the

respective annual limit in the revised Part 20 (e.g.,

shallow dose equivalent to the skin of 35 rems in the

current quarter and year to date), is the individual

unavailable for further exposure in that dose category for

the remainder of the year? (4) If the individual has

received a planned special exposure (PSE) at the previous

workplace in the current quarter, how should the PSE dose

be accounted for as prior occupational dose by the present

licensee under the "old" Part 20? Should the PSE dose be

subtracted from the available current quarter dose for that

dose category?



(b) In the case of a worker whose dose was monitored

earlier in the year at a licensee that has not implemented

the revised Part 20 and is now inprocessing at a licensee

that has implemented the revised Part 20: if the

individual has received recorded internal dose (in terms of

rem) or internal exposure (in terms of MPC-hrs) or internal

uptake (in terms of organ burden), how should this data be

considered with regard to revised Part 20 requirements

(i.e., TEDE, CEDE, or CDE)?



Answer: (a) (1) DDE. (2) Yes, the individual is

"unavailable for any further exposure in that dose category

for the remainder of the quarter" because the individual

has already exceeded the applicable dose limit for the

quarter. (3) The individual is unavailable for further

exposure in that dose category for the remainder of the

quarter (because the individual has exceeded the applicable

dose limit for the quarter), but is available for further

exposure in that dose category for the remainder of the

year after the end of the quarter. (4) The PSE dose should

be accounted for as occupational dose received during the

quarter and should be subtracted from the available current

quarter dose for the dose category.



b) CEDE. (Reference: 10 CFR 20.2104).









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