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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).