United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 420: This question refers to the answer to

Question 55 in §20.2104. (a) Despite the quoted reference,

§20.2104 only refers to occupational radiation dose (why

radiation when the defined term is occupational dose?),

which is defined in terms of "dose." (b) The definition of

dose does not include eye, shallow, or extremity doses.

What is the regulatory basis for including eye, shallow,

and extremity doses within the scope of §20.2104 where it

is so explicitly not included? A simple discussion in the

Statement of Considerations does not seem to be an adequate

basis for rewriting a regulation. (c) Are the dose

histories of these three organs (eye, skin, extremity) so

high as to necessitate the paperwork to track these for new

employees? I suspect that for the vast majority of

workers, these are negligible compared to TEDE.

Answer:

a) "Dose" and "radiation dose" are synonymous (see "Dose or

radiation dose" in §20.1003); therefore, "occupational

dose" and "occupation radiation dose" are synonymous.

(b) Contrary to the statement in the question, "dose or

radiation dose" is broadly defined in Part 20 as "a generic

term that means absorbed dose, dose equivalent, effective

dose equivalent, committed dose equivalent, committed

effective dose equivalent, or total effective dose

equivalent, as defined in other paragraphs of . . . [10 CFR

20.1003]." The "eye dose equivalent" and the "shallow dose

equivalent" (the quantity used in the limits for the skin

and for the extremities) are both "dose equivalent"

quantities and, therefore, are "doses" as defined in Part

20. The occupational dose limits include limits for the

eye, shallow, and extremity doses and the "occupational

dose" in 10 CFR 20.2104 (a) (1) includes the eye, shallow,

and extremity doses. The recommendation in the Statement

of Considerations (which is not an explicit requirement in

the regulation) that, in establishing administrative

controls, the licensee should reduce the values for limits

other than the TEDE by one quarter of their annual limit

for each unreported quarter provides a method, acceptable

to the NRC staff, for licensees to demonstrate compliance

with those limits when records of those doses are missing

for a portion of the year.

(c) A licensee is required to determine a particular

occupational dose received by a new employee earlier in the

current year only if the licensee makes the prospective

determination that individual monitoring will be required,

pursuant to 10 CFR 20.1502, for the prospective

occupational dose. If the licensee determines that

individual monitoring for eye or shallow or extremity dose

are not required for a particular individual (because, at

the licensee's facility, those doses are not likely to

exceed 10 percent of the limits for those doses), the

licensee is not required to determine the prior eye or

shallow or extremity doses. (References: 10 CFR 20.2104,

10 CFR 20.1003).

Page Last Reviewed/Updated Thursday, March 29, 2012