| (A) use that information to calculate the committed
effective dose equivalent, and, if used, the licensee shall document
that information in the individual's record;
(B) upon prior approval of the agency, adjust the DAC
or ALI values to reflect the actual physical and chemical characteristics
of airborne radioactive material, for example, aerosol size distribution
or density; and
(C) separately assess the contribution of fractional
intakes of Class D, W, or Y compounds of a given radionuclide to the
committed effective dose equivalent. See subsection (ggg)(2) of this
section.
(4) If the licensee chooses to assess intakes of Class
Y material using the measurements given in paragraph (1)(A) or (B)
of this subsection, the licensee may delay the recording and reporting
of the assessments for periods up to seven months, unless otherwise
required by subsections (xx) or (yy) of this section. This delay permits
the licensee to make additional measurements basic to the assessments.
(5) If the identity and concentration of each radionuclide
in a mixture are known, the fraction of the DAC applicable to the
mixture for use in calculating DAC-hours shall be either:
(A) the sum of the ratios of the concentration to the
appropriate DAC value, that is, D, W, or Y, from subsection (ggg)(2)
of this section for each radionuclide in the mixture; or
(B) the ratio of the total concentration for all radionuclides
in the mixture to the most restrictive DAC value for any radionuclide
in the mixture.
(6) If the identity of each radionuclide in a mixture
is known, but the concentration of one or more of the radionuclides
in the mixture is not known, the DAC for the mixture shall be the
most restrictive DAC of any radionuclide in the mixture.
(7) When a mixture of radionuclides in air exists,
a licensee may disregard certain radionuclides in the mixture if:
(A) the licensee uses the total activity of the mixture
in demonstrating compliance with the dose limits in subsection (f)
of this section and in complying with the monitoring requirements
in subsection (q)(3) of this section;
(B) the concentration of any radionuclide disregarded
is less than 10% of its DAC; and
(C) the sum of these percentages for all of the radionuclides
disregarded in the mixture does not exceed 30%.
(8) When determining the committed effective dose equivalent,
the following information may be considered.
(A) In order to calculate the committed effective dose
equivalent, the licensee may assume that the inhalation of 1 ALI,
or an exposure of 2,000 DAC-hours, results in a committed effective
dose equivalent of 5 rems (0.05 Sv) for radionuclides that have their
ALIs or DACs based on the committed effective dose equivalent.
(B) For an ALI and the associated DAC determined by
the nonstochastic organ dose limit of 50 rems (0.5 Sv), the intake
of radionuclides that would result in a committed effective dose equivalent
of 5 rems (0.05 Sv), that is, the stochastic ALI, is listed in parentheses
in Table I of subsection (ggg)(2) of this section. The licensee may,
as a simplifying assumption, use the stochastic ALI to determine committed
effective dose equivalent. However, if the licensee uses the stochastic
ALI, the licensee shall also demonstrate that the limit in subsection
(f)(1)(A)(ii) of this section is met.
(j) Determination of occupational dose for the current
year.
(1) For each individual who is likely to receive, in
a year, an occupational dose requiring monitoring in accordance with
subsection (q) of this section, the licensee shall determine the occupational
radiation dose received during the current year.
(2) In complying with the requirements of paragraph
(1) of this subsection, a licensee may:
(A) accept, as a record of the occupational dose that
the individual received during the current year, RC Form 202-2 from
prior or other current employers, or other clear and legible record,
of all information required on that form and indicating any periods
of time for which data are not available; or
(B) accept, as a record of the occupational dose that
the individual received during the current year, a written signed
statement from the individual, or from the individual's prior or other
current employer(s) for work involving radiation exposure, that discloses
the nature and the amount of any occupational dose that the individual
received during the current year; or
(C) obtain reports of the individual's dose equivalent
from prior or other current employer(s) for work involving radiation
exposure, or the individual's current employer, if the individual
is not employed by the licensee, by telephone, facsimile, letter,
or other electronic media transmission. The licensee shall request
a written verification of the dose data if the authenticity of the
transmitted report cannot be established.
(3) The licensee shall record the exposure data for
the current year, as required by paragraph (1) of this subsection,
on RC Form 202-3, or other clear and legible record, of all the information
required on that form.
(4) If the licensee is unable to obtain a complete
record of an individual's current occupational dose while employed
by any other licensee, the licensee shall assume in establishing administrative
controls in accordance with subsection (f)(7) of this section for
the current year, that the allowable dose limit for the individual
is reduced by 1.25 rems (12.5 mSv) for each quarter; or 416 mrem (4.16
mSv) for each month for which records were unavailable and the individual
was engaged in activities that could have resulted in occupational
radiation exposure.
(5) If an individual has incomplete (e.g., a lost or
damaged personnel monitoring device) current occupational dose data
for the current year and that individual is employed solely by the
licensee during the current year, the licensee shall:
(A) assume that the allowable dose limit for the individual
is reduced by 1.25 rems (12.5 mSv) for each quarter;
(B) assume that the allowable dose limit for the individual
is reduced by 416 mrem (4.16 mSv) for each month; or
(C) assess an occupational dose for the individual
during the period of missing data using surveys, radiation measurements,
or other comparable data for the purpose of demonstrating compliance
with the occupational dose limits.
(6) Administrative controls established in accordance
with paragraph (4) of this subsection shall be documented and maintained
for inspection by the agency. Occupational dose assessments made in
accordance with paragraph (5) of this subsection and records of data
used to make the assessment shall be maintained for inspection by
the agency. The licensee shall retain the records in accordance with
subsection (rr) of this section.
(k) Planned special exposures. A licensee may authorize
an adult worker to receive doses in addition to and accounted for
separately from the doses received under the limits specified in subsection
(f) of this section provided that each of the following conditions
is satisfied.
(1) The licensee authorizes a planned special exposure
only in an exceptional situation when alternatives that might avoid
the doses estimated to result from the planned special exposure are
unavailable or impractical.
(2) The licensee and employer, if the employer is not
the licensee, specifically authorizes the planned special exposure,
in writing, before the exposure occurs.
(3) Before a planned special exposure, the licensee
ensures that each individual involved is:
(A) informed of the purpose of the planned operation;
(B) informed of the estimated doses and associated
potential risks and specific radiation levels or other conditions
that might be involved in performing the task; and
(C) instructed in the measures to be taken to keep
the dose ALARA considering other risks that may be present.
(4) Prior to permitting an individual to participate
in a planned special exposure, the licensee shall determine:
(A) the internal and external doses from all previous
planned special exposures;
(B) all doses in excess of the limits, including doses
received during accidents and emergencies, received during the lifetime
of the individual; and
(C) all lifetime cumulative occupational radiation
doses.
(5) In complying with the requirements of paragraph
(4)(C) of this subsection, a licensee may:
(A) accept, as the record of lifetime cumulative radiation
dose, an up-to-date RC Form 202-2 or equivalent, signed by the individual
and countersigned by an appropriate official of the most recent employer
for work involving radiation exposure, or the individual's current
employer, if the individual is not employed by the licensee; and
Cont'd... |
