1983-1988, annual average 3 H concentrations in
the river (<200 pCi/L) were at least a factor of
100 below the drinking water limit (Jaquish and
Bryce, 1989). It is noteworthy that 3 H also
occurs in the Columbia River upstream of Hanford.
From 1983-1988, annual average 3 H concentrations
in the river, upstream at Priest Rapids Dam,
ranged from 70-100 pCi/L.
Surface Water
Columbia River water is used for drinking at
downstream cities, for crop irrigation and for
recreational activities (fishing, hunting,
boating, waterskiing, swimming). Thus, it
constitutes a primary environmental pathway to
people for radioactivity in liquid effluents.
Radionuclides can enter human foodstuffs through
crops irrigated with river water and cow's milk
through irrigated alfalfa and other cattle
forage. Although radionuclides associated with
Hanford operations, worldwide fallout and natural
phenomena continue to be found in small but
measurable quantities in the Columbia River,
concentrations are below Washington State and
Environmental Protection Agency (EPA) drinking
water standards.
Deep sediments in downstream reservoirs still
contain low concentrations of some long-lived
radionuclides (Nelson and Haushild, 1970;
Haushild et al., 1975; Robertson and Fix, 1977;
Sula, 1980; Beasley et al., 1981). Trace amounts
of 239 Pu 60 Co, 137 Cs, and 152 Eu persist in sediments
accumulated above the first downstream dam
(McNary). In 1977, about 20 to 25% of the total
plutonium inventory ( 239 . 240 . 241 p u ) i n Lake Wallula
sediments, 100 km downstream, was believed to
originate from the 1944 through 1971 releases at
Hanford (Beasley et al., 1981). However, only
239 Pu was believed to actually reflect earlier
reactor operations. Furthermore, this 239 Pu was
derived from 239 Np (produced by neutron capture in
natural uranium followed by decay to 239 Np), an
abundant isotope in Columbia River water. Thus,
plutonium may not have been released to the river
from reactor operations.
Fish and Wildlife
Fish are collected at various locations along the
Columbia River and boneless fillets are analyzed
for 60 Co, 90 Sr, and 137 Cs. Carcasses are analyzed
to estimate 90 Sr in bone. Following shutdown of
the last single-purpose, once-through cooling
reactor and installation of improved liquid
effluent control systems at N Reactor, short
lived radionuclides, including the biologically
important 32 P and 65 Zn, essentially disappeared
from the river (Cushing et al., 1981) through
radioactive decay. Radionuclide concentrations
in fish collected from the Hanford Reach of the
Columbia River are similar to those in fish from
upstream locations.
Deer (Odocoileus sp.), ring-necked pheasants
(Phasianus colchicus), mallard ducks (Anas
piatvrhvnchus), Nuttall cottontail rabbits
(Svlvilagus nuttallii) and black-tailed jack
rabbits (Lepus californicus) are collected and
tissues are analyzed for ^Co and 137 Cs (muscle),
239.240p u (-|-j ver ) anc | 90$ r (berne). The doses that
could be received by consuming wildlife at the
maximum radionuclide concentrations measured in
1985-1988 were below applicable DOE standards
(Price, 1986; PNL, 1987; Jaquish and Mitchell,
1988; Jaquish and Bryce, 1989).
Soil and Vegetation
Airborne radionuclides are eventually deposited on
vegetation or soil. Samples of surface soil and
rangeland vegetation (sagebrush) are currently
collected at 15 onsite and 23 site perimeter and
offsite locations (Jaquish and Bryce, 1989). Sam
ples are collected from nonagricultural, undis
turbed sites so that natural deposition and
buildup processes are represented. Sampling and
analyses in 1985 through 1988 showed no radio
nuclide buildup offsite that could be attributed
to Hanford operations (Price, 1986; PNL, 1987;
Jaquish and Mitchell, 1988; Jaquish and Bryce,
1989).
Foodstuffs
The most direct way for deposited radionuclides to
enter the foodchain is through consumption of
leafy vegetables. Samples of alfalfa and several
foodstuffs, including milk, vegetables, fruits,
wine, beef, chickens, eggs and wheat, are col
lected from several locations, primarily downwind
(i.e., south and east) of the Site (Jaquish and
Bryce,'1989). Samples are also collected from
upwind and somewhat distant locations to provide
information on radiation levels attributable to
worldwide fallout. Foodstuffs from the Riverview
Area (across the river and southeast) are irri
gated with Columbia River water withdrawn down
stream of the Site. Although low levels of 3 H,
90 Sr, 129 I, and 137 Cs have been found in some food
stuffs, concentrations in samples collected near
Hanford are similar to those in samples collected
away from the Site.
Penetrating Radiation
Penetrating radiation (primarily gamma-rays) is
measured in the Hanford environs with thermolumi
nescent dosimeters to estimate dose rates from
external radiation sources. Radiation surveys are
routinely conducted at numerous onsite locations
including roads, railroads and retired waste-
disposal sites located outside of operating areas.
Onsite and offsite measurements and survey results
for 1985-1988 were similar to past years. Dose
rates near some operating facilities were only
slightly higher than natural background rates.
Overall Impact from Hanford Operations
Beginning in 1974, evaluation of radiation doses
has included assessment of the maximum external
dose rate at a location accessible to the general
public, doses to a hypothetical maximally exposed
individual, and doses to the population within
80 km (50 mi) of the Site. The calculated 50-year
whole-body cumulative dose received by the maxi
mally exposed individual ranged from 0.5 to 3 mrem
during the years 1981 through 1986 (PNL, 1987).
This hypothetical person receives the maximum
calculated radiation dose using worst-case assump
tions for location, inhalation of radioactive
emissions, consumption of contaminated food and
water, and direct exposure to contaminants.
Expressed as effective dose equivalents, the
calculated dose received by a hypothetical maxi
mally exposed individual was 0.05 to 0.1 mrem
annually from 1985 through 1988. The average per
capita effective dose from 1985 through 1988,
based on the human population of 340,000 within
80 km of the Site, was 0.01 to 0.03 mrem annually
(Price, 1986; PNL, 1987; Jaquish and Mitchell,
1988; Jaquish and Bryce, 1989). Based on these
assessments, potential radiation doses to the
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