-43-
HW-80991
because of the presence of gamma emitters, especially Na@4, from reactor
effluent.
Near Richland and Pasco the average dose rates measured in the
river during the months of April through October were about 2 and 1.5 mr
per day, respectively.
Further upstream near the laboratories area the
dose rate was 3 mr per day.
A person swimming or boating in the river for
240 hours during the year would receive about 20 mr total body exposure in
the vicinity of Richland and about 15 mr near Pasco.
Measurements of
immersion dose are shown in Appendix D, Table 2.
At the river shoreline radiation measurements indicated the dose
rate was about 0.25 mr/hour from radionuclides deposited with debris and
in the mud and sandby the fluctuating water level.
An ardent fisherman
spending 6 hours per week, 8 months of the year, along the river bank in the
vicinity of Richland would receive an annual whole body exposure of about
50 mr.
J.
Radioactive Wastes Released to Ground
Liquid wastes from the Chemical Separations areas are routed to vari-
ous facilities dependent upon their burden of radionuclides.
High level wastes,
normally containing concentrations greater than 100 uc/cc, are stored in concrete tanks lined with steel.
Intermediate level wastes, ordinarily containing
concentrations in the range of 5 x 107° uc/ec to 100 uc/ec, are sent to underground "cribs'' from which they percolate into the soil. Low level wastes, usually
containing less than 5 x 107> ue/ce, are sent to depressions in the ground
where surface ponds or ''swamps"’ have been formed as a result of the continuous addition of relatively large volumes.
The areas selected for liquid waste
disposal have soil with good ion exchange capacity and depths of 150 to 350 feet
to ground water.
One important objective in the management of wastes placed in the
ground is the prevention of radiologically important radionuclides from reaching
the ground water in quantities that could ultimately cause significant human expo-
sure should they migrate to the Columbia River.
For this reason wells have been
drilled in and around crib and tank storage areas to detect any leaks in the tanks