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HW -80991
The Hanford Ferry monitoring station is about 7 miles downstream
from the closest production reactor and about 6 miles upstream from the
point where the project boundary crosses the Columbia River.
Studies of
effluent distribution at the Hanford Ferry indicate nonuniformity which
causes sample results to show higher concentrations of most radionuclides
than the average of the cross section at this location.
Measurements ona
traverse across the river at Richland indicated a fairly uniform distribution
of the longer-liver radioisotopes throughout the river at this point.
At
Pasco, the distribution of radioisotopes in the river is slightly nonuniform
because of the entry of the Yakima River some 10 miles upstream.
Vancouver, about 260 miles from the reactors, is the farthest down-
stream location where river water is routinely sampled for’Hanford's surveillance program.
Further downstream the intrusion of sea water into the
Columbia River complicates quantitative measurement of the radionuclides.
Seasonal variation in the flow rate of the Columbia River markedly
affects the quantity of water available for dilution of the reactor effluent.
Also affected is the time required for a specific volume of water to move
from one location to another.
The flow rate of the Columbia River at Pasco
and Vancouver for 1959 through 1963 is shown in Figure 4.
The variation in
concentration of several radionuclides in the river water at Pasco for the
Same period is shown in Figure 5.
The rate of transport of these same radio-
nuclides past Pasco is shown in Figure 6, and in Table 8 of Appendix A.
The rate of transport of certain radionuclides passing Vancouver may be used
as an index of the quantities entering the Pacific Ocean from the Columbia
River.
The annual average rate of transport of selected radionuclides is
given in Table UI and detailed measurements are tabulated in Appendix A,
Table 9.
TABLEIII
ANNUAL AVERAGE RATE OF TRANSPORT
OF SELECTED RADIONUCLIDES PAST VANCOUVER
Curies/day
Radionuclides
p??
cr?!
zn°°
1963
1962
1961
12
860
28
13
630
29
29
840
44