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HW-80991
Fhe inventory of each of these nuclides which exists in the ocean
can be calculated by assuming an equilibrium between the rate of addition
through the river and the rate of decay in the ocean.
A constant rate of
entry into the ocean equivalent to that indicated by the 1963 Vancouver
measurements,
implies inventories of about 250 curies of ps2
30, 000
curies of crt, and 9,000 curies of zn®° |
Radiation exposure that results from the drinking of water pumped
from the river and sent through treatment plants is discussed in the next
section of this report.
There is no known instance of untreated river
water being consumed routinely by humans.
For comparative purposes,
however, the relationship between the concentrations of radionuclides in
the untreated Columbia River water and published values for maximum
permissible concentrations in water is shown in Table IV.
In this case
the comparison is with the MPC's listed in Column 2, Table II of Annex I
of AEC Manual Chapter Appendix 0524, (2) For the most part these MPC's
are equivalent to one-tenth of the most limiting values recommended by the
ncRP'?) for occupational workers.
The marked reduction in percentof
MPC, that occurs with distance downstream from the reactors results
principally from radioactive decay of the shorter-lived nuclides.
TABLE IV
RELATIONSHIP BETWEEN THE CONCENTRATIONS
OF RADIONUCLIDES IN UNTREATED COLUMBIA RIVER WATER
AND MAXIMUM PERMISSIBLE CONCENTRATIONS
Sampling Location
% of MPc*
Hanford
34
Richland
17
Pasco
12
Vancouver
.
2
* This is a Summation of the percents of MPC's contributed
by the several individual radionuclides measured routinely
in the river water. The MPC's used and the method of
summation are taken from AEC Manual Chapter 0524. (?)