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HW-80991
Consumption of oysters containing these concentrations of zn®° and p?2 at
a sustained rate of one meal per week (1/2 1b) would lead to an annual exposure of about 9 mrems to the GI tract,
6 mrems to the total body, and less
than 0.5% of the MPRI for bone.
E.
Radionuclides in the Atmosphere
At Hanford, gaseous waste is released to the atmosphere through
200 ft high stacks after removal of some 99% of the radioactive materials
present.
These radioactive materials are primarily associated with
process vessel off-gases from the chemical separations facilities.
normal operating conditions,
Under
the ventilation air from laboratory and reac-
tor buildings contains comparatively minor amounts of radioactive
materials.
yi31 is the radionuclide of principal interest in the separations facil-
ities process off-gases.
Measurements for this nuclide are tabulated in
Appendix B, Table 2, and average release rates are shown in Figure 11.
During 1963 the annual average emission rate of I 131 from the separations
plant stacks was 0.38 curie per day.
Monitoring for other specific radio-
isotopes was discontinued in 1963 because previous measurements have
shown insignificant emission rates.
Gross beta measurements are now
made continuously to detect any change in emission rates of these other radionuclides.
The results for the past 2? years are summarized in Table VIII.
The fission product recovery facilities operating at Hanford contributed
negligible amounts of radionuclides to the environs during 1963.
The aver-
age emission rate of gr9° from such facilities was less than 0.0018 curie
per day.
Measurements of air-borne i? 31 were made routinely at several
locations within the Hanford reservation and at several locations adjacent
to the plant.
Results of these measurements for 1963 are presented in
Appendix B, Table 2, and results for the past few years are summarized in
Table IX.