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HW-80991
The AEC Manual Chapters!” and the recommendations of the
National Committee on Radiation Frotection and Measurement (NCRP), (3)
the International Commission on Radiological Protection (ICRP), (4) the
Federal Radiation Council (FRC), (5) and the results of Hanford research
programs form the basis of radiation protection practices at Hanford.
The
recommendations of these organizations in the form of permissible rates
of intake of specific nuclides and guides for radiation exposure constitute
criteria against which radiation exposures estimated from measurements
of the Hanford environmental surveillance program are compared.
The
results of this comparison indicate the effectiveness of Hanford waste control and radiation protection practices and point out any conditions requiring
attention.
This report estimates the annual exposure received by the individuals
who are expected to receive the greatest amount of radiation from environmental sources, and the exposure received by people who are moretypical
residents of this region.
These exposures are compared with the recom-
mendations of the NCRP and FRC.
The NCRP recommendations, in the
form of maximum permissible exposures for individuals that are not employed in radiation work are 1500 mrems per year to the Gl tract, 500 mrems
per year to the total body, and 3000 mrems tothe thyroid.
The limits for
bone-seekers are calculated with reference to biological effects observed
from deposition of radium and are most readily applied in the form of maxi-
mum permissible rates of intake (MPRI).* Similar evaluations for previous
years have also been reported. ‘1: 5: 7) The Radiation Protection Guides
established by the FRC for individuals are 1500 mrems per year to the thyroid,
1500 mrems per year to the bone, and 500 mrems to the whole body.
The Radiation Protection Guides for the "average of a suitable sampleof an
exposed population group’ are one-third of those for individuals.
* The MPRIis taken as the maximum permissible concentration in water for
a given radionuclide, as recommended -ty the NCRP for persons in the
neighborhood of controlled areas, multiplied by the rate of water intake
as defined for the standard man. This amounts to one-tenth of the MPC's
for continuous exposure of occupational workers multiplied by 2200 cc
per day, or by 800 liters per year in the case of annual estimates.